Linus Torvalds [Thu, 16 Nov 2017 17:10:59 +0000 (09:10 -0800)]
Merge tag 'char-misc-4.15-rc1' of ssh://gitolite./linux/kernel/git/gregkh/char-misc
Pull char/misc updates from Greg KH:
"Here is the big set of char/misc and other driver subsystem patches
for 4.15-rc1.
There are small changes all over here, hyperv driver updates, pcmcia
driver updates, w1 driver updats, vme driver updates, nvmem driver
updates, and lots of other little one-off driver updates as well. The
shortlog has the full details.
All of these have been in linux-next for quite a while with no
reported issues"
* tag 'char-misc-4.15-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (90 commits)
VME: Return -EBUSY when DMA list in use
w1: keep balance of mutex locks and refcnts
MAINTAINERS: Update VME subsystem tree.
nvmem: sunxi-sid: add support for A64/H5's SID controller
nvmem: imx-ocotp: Update module description
nvmem: imx-ocotp: Enable i.MX7D OTP write support
nvmem: imx-ocotp: Add i.MX7D timing write clock setup support
nvmem: imx-ocotp: Move i.MX6 write clock setup to dedicated function
nvmem: imx-ocotp: Add support for banked OTP addressing
nvmem: imx-ocotp: Pass parameters via a struct
nvmem: imx-ocotp: Restrict OTP write to IMX6 processors
nvmem: uniphier: add UniPhier eFuse driver
dt-bindings: nvmem: add description for UniPhier eFuse
nvmem: set nvmem->owner to nvmem->dev->driver->owner if unset
nvmem: qfprom: fix different address space warnings of sparse
nvmem: mtk-efuse: fix different address space warnings of sparse
nvmem: mtk-efuse: use stack for nvmem_config instead of malloc'ing it
nvmem: imx-iim: use stack for nvmem_config instead of malloc'ing it
thunderbolt: tb: fix use after free in tb_activate_pcie_devices
MAINTAINERS: Add git tree for Thunderbolt development
...
Linus Torvalds [Thu, 16 Nov 2017 16:55:30 +0000 (08:55 -0800)]
Merge tag 'driver-core-4.15-rc1' of git://git./linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here is the set of driver core / debugfs patches for 4.15-rc1.
Not many here, mostly all are debugfs fixes to resolve some
long-reported problems with files going away with references to them
in userspace. There's also some SPDX cleanups for the debugfs code, as
well as a few other minor driver core changes for issues reported by
people.
All of these have been in linux-next for a week or more with no
reported issues"
* tag 'driver-core-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
driver core: Fix device link deferred probe
debugfs: Remove redundant license text
debugfs: add SPDX identifiers to all debugfs files
debugfs: defer debugfs_fsdata allocation to first usage
debugfs: call debugfs_real_fops() only after debugfs_file_get()
debugfs: purge obsolete SRCU based removal protection
IB/hfi1: convert to debugfs_file_get() and -put()
debugfs: convert to debugfs_file_get() and -put()
debugfs: debugfs_real_fops(): drop __must_hold sparse annotation
debugfs: implement per-file removal protection
debugfs: add support for more elaborate ->d_fsdata
driver core: Move device_links_purge() after bus_remove_device()
arch_topology: Fix section miss match warning due to free_raw_capacity()
driver-core: pr_err() strings should end with newlines
Linus Torvalds [Thu, 16 Nov 2017 04:42:10 +0000 (20:42 -0800)]
Merge tag 'drm-for-v4.15' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
"This is the main drm pull request for v4.15.
Core:
- Atomic object lifetime fixes
- Atomic iterator improvements
- Sparse/smatch fixes
- Legacy kms ioctls to be interruptible
- EDID override improvements
- fb/gem helper cleanups
- Simple outreachy patches
- Documentation improvements
- Fix dma-buf rcu races
- DRM mode object leasing for improving VR use cases.
- vgaarb improvements for non-x86 platforms.
New driver:
- tve200: Faraday Technology TVE200 block.
This "TV Encoder" encodes a ITU-T BT.656 stream and can be found in
the StorLink SL3516 (later Cortina Systems CS3516) as well as the
Grain Media GM8180.
New bridges:
- SiI9234 support
New panels:
- S6E63J0X03, OTM8009A, Seiko 43WVF1G, 7" rpi touch panel, Toshiba
LT089AC19000, Innolux AT043TN24
i915:
- Remove Coffeelake from alpha support
- Cannonlake workarounds
- Infoframe refactoring for DisplayPort
- VBT updates
- DisplayPort vswing/emph/buffer translation refactoring
- CCS fixes
- Restore GPU clock boost on missed vblanks
- Scatter list updates for userptr allocations
- Gen9+ transition watermarks
- Display IPC (Isochronous Priority Control)
- Private PAT management
- GVT: improved error handling and pci config sanitizing
- Execlist refactoring
- Transparent Huge Page support
- User defined priorities support
- HuC/GuC firmware refactoring
- DP MST fixes
- eDP power sequencing fixes
- Use RCU instead of stop_machine
- PSR state tracking support
- Eviction fixes
- BDW DP aux channel timeout fixes
- LSPCON fixes
- Cannonlake PLL fixes
amdgpu:
- Per VM BO support
- Powerplay cleanups
- CI powerplay support
- PASID mgr for kfd
- SR-IOV fixes
- initial GPU reset for vega10
- Prime mmap support
- TTM updates
- Clock query interface for Raven
- Fence to handle ioctl
- UVD encode ring support on Polaris
- Transparent huge page DMA support
- Compute LRU pipe tweaks
- BO flag to allow buffers to opt out of implicit sync
- CTX priority setting API
- VRAM lost infrastructure plumbing
qxl:
- fix flicker since atomic rework
amdkfd:
- Further improvements from internal AMD tree
- Usermode events
- Drop radeon support
nouveau:
- Pascal temperature sensor support
- Improved BAR2 handling
- MMU rework to support Pascal MMU
exynos:
- Improved HDMI/mixer support
- HDMI audio interface support
tegra:
- Prep work for tegra186
- Cleanup/fixes
msm:
- Preemption support for a5xx
- Display fixes for 8x96 (snapdragon 820)
- Async cursor plane fixes
- FW loading rework
- GPU debugging improvements
vc4:
- Prep for DSI panels
- fix T-format tiling scanout
- New madvise ioctl
Rockchip:
- LVDS support
omapdrm:
- omap4 HDMI CEC support
etnaviv:
- GPU performance counters groundwork
sun4i:
- refactor driver load + TCON backend
- HDMI improvements
- A31 support
- Misc fixes
udl:
- Probe/EDID read fixes.
tilcdc:
- Misc fixes.
pl111:
- Support more variants
adv7511:
- Improve EDID handling.
- HDMI CEC support
sii8620:
- Add remote control support"
* tag 'drm-for-v4.15' of git://people.freedesktop.org/~airlied/linux: (1480 commits)
drm/rockchip: analogix_dp: Use mutex rather than spinlock
drm/mode_object: fix documentation for object lookups.
drm/i915: Reorder context-close to avoid calling i915_vma_close() under RCU
drm/i915: Move init_clock_gating() back to where it was
drm/i915: Prune the reservation shared fence array
drm/i915: Idle the GPU before shinking everything
drm/i915: Lock llist_del_first() vs llist_del_all()
drm/i915: Calculate ironlake intermediate watermarks correctly, v2.
drm/i915: Disable lazy PPGTT page table optimization for vGPU
drm/i915/execlists: Remove the priority "optimisation"
drm/i915: Filter out spurious execlists context-switch interrupts
drm/amdgpu: use irq-safe lock for kiq->ring_lock
drm/amdgpu: bypass lru touch for KIQ ring submission
drm/amdgpu: Potential uninitialized variable in amdgpu_vm_update_directories()
drm/amdgpu: potential uninitialized variable in amdgpu_vce_ring_parse_cs()
drm/amd/powerplay: initialize a variable before using it
drm/amd/powerplay: suppress KASAN out of bounds warning in vega10_populate_all_memory_levels
drm/amd/amdgpu: fix evicted VRAM bo adjudgement condition
drm/vblank: Tune drm_crtc_accurate_vblank_count() WARN down to a debug
drm/rockchip: add CONFIG_OF dependency for lvds
...
Linus Torvalds [Thu, 16 Nov 2017 04:30:12 +0000 (20:30 -0800)]
Merge tag 'media/v4.15-1' of ssh://gitolite./linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
- Documentation for digital TV (both kAPI and uAPI) are now in sync
with the implementation (except for legacy/deprecated ioctls). This
is a major step, as there were always a gap there
- New sensor driver: imx274
- New cec driver: cec-gpio
- New platform driver for rockship rga and tegra CEC
- New RC driver: tango-ir
- Several cleanups at atomisp driver
- Core improvements for RC, CEC, V4L2 async probing support and DVB
- Lots of drivers cleanup, fixes and improvements.
* tag 'media/v4.15-1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (332 commits)
dvb_frontend: don't use-after-free the frontend struct
media: dib0700: fix invalid dvb_detach argument
media: v4l2-ctrls: Don't validate BITMASK twice
media: s5p-mfc: fix lockdep warning
media: dvb-core: always call invoke_release() in fe_free()
media: usb: dvb-usb-v2: dvb_usb_core: remove redundant code in dvb_usb_fe_sleep
media: au0828: make const array addr_list static
media: cx88: make const arrays default_addr_list and pvr2000_addr_list static
media: drxd: make const array fastIncrDecLUT static
media: usb: fix spelling mistake: "synchronuously" -> "synchronously"
media: ddbridge: fix build warnings
media: av7110: avoid 2038 overflow in debug print
media: Don't do DMA on stack for firmware upload in the AS102 driver
media: v4l: async: fix unregister for implicitly registered sub-device notifiers
media: v4l: async: fix return of unitialized variable ret
media: imx274: fix missing return assignment from call to imx274_mode_regs
media: camss-vfe: always initialize reg at vfe_set_xbar_cfg()
media: atomisp: make function calls cleaner
media: atomisp: get rid of storage_class.h
media: atomisp: get rid of wrong stddef.h include
...
Linus Torvalds [Thu, 16 Nov 2017 04:11:56 +0000 (20:11 -0800)]
Merge tag 'leaks-4.15-rc1' of git://github.com/tcharding/linux
Pull leaking_addresses script updates from Tobin Harding:
"Here are development patches for the leaking_addresses.pl script.
Changes include:
- add summary reporting to the script
- add 'SigIgn' to false positives
- add a file read timeout so the script doesn't block indefinitely
- add infrastructure to enable multi-arch support and add support for ppc
- add some exclude files/paths suggested by various people
- code clean up and refactoring
- overhaul command line options"
* tag 'leaks-4.15-rc1' of git://github.com/tcharding/linux:
leaking_addresses: add SigIgn to false positives
leaking_addresses: add timeout on file read
leaking_addresses: add support for ppc64
leaking_addresses: add summary reporting options
leaking_addresses: add to exclude files/paths list
leaking_addresses: fix comment string typo
leaking_addresses: remove command line options
leaking_addresses: remove dead/unused code
leaking_addresses: use tabs instead of spaces
Linus Torvalds [Thu, 16 Nov 2017 03:42:40 +0000 (19:42 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
- a few misc bits
- ocfs2 updates
- almost all of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (131 commits)
memory hotplug: fix comments when adding section
mm: make alloc_node_mem_map a void call if we don't have CONFIG_FLAT_NODE_MEM_MAP
mm: simplify nodemask printing
mm,oom_reaper: remove pointless kthread_run() error check
mm/page_ext.c: check if page_ext is not prepared
writeback: remove unused function parameter
mm: do not rely on preempt_count in print_vma_addr
mm, sparse: do not swamp log with huge vmemmap allocation failures
mm/hmm: remove redundant variable align_end
mm/list_lru.c: mark expected switch fall-through
mm/shmem.c: mark expected switch fall-through
mm/page_alloc.c: broken deferred calculation
mm: don't warn about allocations which stall for too long
fs: fuse: account fuse_inode slab memory as reclaimable
mm, page_alloc: fix potential false positive in __zone_watermark_ok
mm: mlock: remove lru_add_drain_all()
mm, sysctl: make NUMA stats configurable
shmem: convert shmem_init_inodecache() to void
Unify migrate_pages and move_pages access checks
mm, pagevec: rename pagevec drained field
...
Fan Du [Thu, 16 Nov 2017 01:39:21 +0000 (17:39 -0800)]
memory hotplug: fix comments when adding section
Here, pfn_to_node should be page_to_nid.
Link: http://lkml.kernel.org/r/1510735205-22540-1-git-send-email-fan.du@intel.com
Signed-off-by: Fan Du <fan.du@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oscar Salvador [Thu, 16 Nov 2017 01:39:18 +0000 (17:39 -0800)]
mm: make alloc_node_mem_map a void call if we don't have CONFIG_FLAT_NODE_MEM_MAP
free_area_init_node() calls alloc_node_mem_map(), but this function does
nothing unless we have CONFIG_FLAT_NODE_MEM_MAP.
As a cleanup, we can move the "#ifdef CONFIG_FLAT_NODE_MEM_MAP" within
alloc_node_mem_map() out of the function, and define a
alloc_node_mem_map() { } when CONFIG_FLAT_NODE_MEM_MAP is not present.
This also moves the printk that lays within the "#ifdef
CONFIG_FLAT_NODE_MEM_MAP" block from free_area_init_node() to
alloc_node_mem_map(), getting rid of the "#ifdef
CONFIG_FLAT_NODE_MEM_MAP" in free_area_init_node().
[akpm@linux-foundation.org: clean up the printk while we're there]
Link: http://lkml.kernel.org/r/20171114111935.GA11758@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@techadventures.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 16 Nov 2017 01:39:14 +0000 (17:39 -0800)]
mm: simplify nodemask printing
alloc_warn() and dump_header() have to explicitly handle NULL nodemask
which forces both paths to use pr_cont. We can do better. printk
already handles NULL pointers properly so all we need is to teach
nodemask_pr_args to handle NULL nodemask carefully. This allows
simplification of both alloc_warn() and dump_header() and gets rid of
pr_cont altogether.
This patch has been motivated by patch from Joe Perches
http://lkml.kernel.org/r/
b31236dfe3fc924054fd7842bde678e71d193638.
1509991345.git.joe@perches.com
[akpm@linux-foundation.org: fix tile warning, per Arnd]
Link: http://lkml.kernel.org/r/20171109100531.3cn2hcqnuj7mjaju@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tetsuo Handa [Thu, 16 Nov 2017 01:39:10 +0000 (17:39 -0800)]
mm,oom_reaper: remove pointless kthread_run() error check
Since oom_init() is called before userspace processes start, memory
allocation failure for creating the OOM reaper kernel thread will let
the OOM killer call panic() rather than wake up the OOM reaper.
Link: http://lkml.kernel.org/r/1510137800-4602-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jaewon Kim [Thu, 16 Nov 2017 01:39:07 +0000 (17:39 -0800)]
mm/page_ext.c: check if page_ext is not prepared
online_page_ext() and page_ext_init() allocate page_ext for each
section, but they do not allocate if the first PFN is !pfn_present(pfn)
or !pfn_valid(pfn). Then section->page_ext remains as NULL.
lookup_page_ext checks NULL only if CONFIG_DEBUG_VM is enabled. For a
valid PFN, __set_page_owner will try to get page_ext through
lookup_page_ext. Without CONFIG_DEBUG_VM lookup_page_ext will misuse
NULL pointer as value 0. This incurrs invalid address access.
This is the panic example when PFN 0x100000 is not valid but PFN
0x13FC00 is being used for page_ext. section->page_ext is NULL,
get_entry returned invalid page_ext address as 0x1DFA000 for a PFN
0x13FC00.
To avoid this panic, CONFIG_DEBUG_VM should be removed so that page_ext
will be checked at all times.
Unable to handle kernel paging request at virtual address
01dfa014
------------[ cut here ]------------
Kernel BUG at
ffffff80082371e0 [verbose debug info unavailable]
Internal error: Oops:
96000045 [#1] PREEMPT SMP
Modules linked in:
PC is at __set_page_owner+0x48/0x78
LR is at __set_page_owner+0x44/0x78
__set_page_owner+0x48/0x78
get_page_from_freelist+0x880/0x8e8
__alloc_pages_nodemask+0x14c/0xc48
__do_page_cache_readahead+0xdc/0x264
filemap_fault+0x2ac/0x550
ext4_filemap_fault+0x3c/0x58
__do_fault+0x80/0x120
handle_mm_fault+0x704/0xbb0
do_page_fault+0x2e8/0x394
do_mem_abort+0x88/0x124
Pre-4.7 kernels also need commit
f86e4271978b ("mm: check the return
value of lookup_page_ext for all call sites").
Link: http://lkml.kernel.org/r/20171107094131.14621-1-jaewon31.kim@samsung.com
Fixes: eefa864b701d ("mm/page_ext: resurrect struct page extending code for debugging")
Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: <stable@vger.kernel.org> [depends on f86e427197, see above]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wang Long [Thu, 16 Nov 2017 01:39:03 +0000 (17:39 -0800)]
writeback: remove unused function parameter
The parameter `struct bdi_writeback *wb` is not been used in the
function body. Remove it.
Link: http://lkml.kernel.org/r/1509685485-15278-1-git-send-email-wanglong19@meituan.com
Signed-off-by: Wang Long <wanglong19@meituan.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 16 Nov 2017 01:38:59 +0000 (17:38 -0800)]
mm: do not rely on preempt_count in print_vma_addr
The preempt count check on print_vma_addr has been added by commit
e8bff74afbdb ("x86: fix "BUG: sleeping function called from invalid
context" in print_vma_addr()") and it relied on the elevated preempt
count from preempt_conditional_sti because preempt_count check doesn't
work on non preemptive kernels by default.
The code has evolved though and commit
d99e1bd175f4 ("x86/entry/traps:
Refactor preemption and interrupt flag handling") has replaced
preempt_conditional_sti by an explicit preempt_disable which is noop on
!PREEMPT so the check in print_vma_addr is broken.
Fix the issue by using trylock on mmap_sem rather than chacking the
preempt count. The allocation we are relying on has to be GFP_NOWAIT as
well. There is a chance that we won't dump the vma state if the lock is
contended or the memory short but this is acceptable outcome and much
less fragile than the not working preemption check or tricks around it.
Link: http://lkml.kernel.org/r/20171106134031.g6dbelg55mrbyc6i@dhcp22.suse.cz
Fixes: d99e1bd175f4 ("x86/entry/traps: Refactor preemption and interrupt flag handling")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Yang Shi <yang.s@alibaba-inc.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 16 Nov 2017 01:38:56 +0000 (17:38 -0800)]
mm, sparse: do not swamp log with huge vmemmap allocation failures
While doing memory hotplug tests under heavy memory pressure we have
noticed too many page allocation failures when allocating vmemmap memmap
backed by huge page
kworker/u3072:1: page allocation failure: order:9, mode:0x24084c0(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO)
[...]
Call Trace:
dump_trace+0x59/0x310
show_stack_log_lvl+0xea/0x170
show_stack+0x21/0x40
dump_stack+0x5c/0x7c
warn_alloc_failed+0xe2/0x150
__alloc_pages_nodemask+0x3ed/0xb20
alloc_pages_current+0x7f/0x100
vmemmap_alloc_block+0x79/0xb6
__vmemmap_alloc_block_buf+0x136/0x145
vmemmap_populate+0xd2/0x2b9
sparse_mem_map_populate+0x23/0x30
sparse_add_one_section+0x68/0x18e
__add_pages+0x10a/0x1d0
arch_add_memory+0x4a/0xc0
add_memory_resource+0x89/0x160
add_memory+0x6d/0xd0
acpi_memory_device_add+0x181/0x251
acpi_bus_attach+0xfd/0x19b
acpi_bus_scan+0x59/0x69
acpi_device_hotplug+0xd2/0x41f
acpi_hotplug_work_fn+0x1a/0x23
process_one_work+0x14e/0x410
worker_thread+0x116/0x490
kthread+0xbd/0xe0
ret_from_fork+0x3f/0x70
and we do see many of those because essentially every allocation fails
for each memory section. This is an excessive way to tell the user that
there is nothing to really worry about because we do have a fallback
mechanism to use base pages. The only downside might be a performance
degradation due to TLB pressure.
This patch changes vmemmap_alloc_block() to use __GFP_NOWARN and warn
explicitly once on the first allocation failure. This will reduce the
noise in the kernel log considerably, while we still have an indication
that a performance might be impacted.
[mhocko@kernel.org: forgot to git add the follow up fix]
Link: http://lkml.kernel.org/r/20171107090635.c27thtse2lchjgvb@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20171106092228.31098-1-mhocko@kernel.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Colin Ian King [Thu, 16 Nov 2017 01:38:52 +0000 (17:38 -0800)]
mm/hmm: remove redundant variable align_end
Variable align_end is assigned a value but it is never read, so the
variable is redundant and can be removed. Cleans up the clang warning:
Value stored to 'align_end' is never read
Link: http://lkml.kernel.org/r/20171017143837.23207-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Gustavo A. R. Silva [Thu, 16 Nov 2017 01:38:49 +0000 (17:38 -0800)]
mm/list_lru.c: mark expected switch fall-through
In preparation for enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Link: http://lkml.kernel.org/r/20171020190754.GA24332@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Gustavo A. R. Silva [Thu, 16 Nov 2017 01:38:45 +0000 (17:38 -0800)]
mm/shmem.c: mark expected switch fall-through
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Link: http://lkml.kernel.org/r/20171020191058.GA24427@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:38:41 +0000 (17:38 -0800)]
mm/page_alloc.c: broken deferred calculation
In reset_deferred_meminit() we determine number of pages that must not
be deferred. We initialize pages for at least 2G of memory, but also
pages for reserved memory in this node.
The reserved memory is determined in this function:
memblock_reserved_memory_within(), which operates over physical
addresses, and returns size in bytes. However, reset_deferred_meminit()
assumes that that this function operates with pfns, and returns page
count.
The result is that in the best case machine boots slower than expected
due to initializing more pages than needed in single thread, and in the
worst case panics because fewer than needed pages are initialized early.
Link: http://lkml.kernel.org/r/20171021011707.15191-1-pasha.tatashin@oracle.com
Fixes: 864b9a393dcb ("mm: consider memblock reservations for deferred memory initialization sizing")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tetsuo Handa [Thu, 16 Nov 2017 01:38:37 +0000 (17:38 -0800)]
mm: don't warn about allocations which stall for too long
Commit
63f53dea0c98 ("mm: warn about allocations which stall for too
long") was a great step for reducing possibility of silent hang up
problem caused by memory allocation stalls. But this commit reverts it,
for it is possible to trigger OOM lockup and/or soft lockups when many
threads concurrently called warn_alloc() (in order to warn about memory
allocation stalls) due to current implementation of printk(), and it is
difficult to obtain useful information due to limitation of synchronous
warning approach.
Current printk() implementation flushes all pending logs using the
context of a thread which called console_unlock(). printk() should be
able to flush all pending logs eventually unless somebody continues
appending to printk() buffer.
Since warn_alloc() started appending to printk() buffer while waiting
for oom_kill_process() to make forward progress when oom_kill_process()
is processing pending logs, it became possible for warn_alloc() to force
oom_kill_process() loop inside printk(). As a result, warn_alloc()
significantly increased possibility of preventing oom_kill_process()
from making forward progress.
---------- Pseudo code start ----------
Before warn_alloc() was introduced:
retry:
if (mutex_trylock(&oom_lock)) {
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_lock)
}
goto retry;
After warn_alloc() was introduced:
retry:
if (mutex_trylock(&oom_lock)) {
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_lock)
} else if (waited_for_10seconds()) {
atomic_inc(&printk_pending_logs);
}
goto retry;
---------- Pseudo code end ----------
Although waited_for_10seconds() becomes true once per 10 seconds,
unbounded number of threads can call waited_for_10seconds() at the same
time. Also, since threads doing waited_for_10seconds() keep doing
almost busy loop, the thread doing print_one_log() can use little CPU
resource. Therefore, this situation can be simplified like
---------- Pseudo code start ----------
retry:
if (mutex_trylock(&oom_lock)) {
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_lock)
} else {
atomic_inc(&printk_pending_logs);
}
goto retry;
---------- Pseudo code end ----------
when printk() is called faster than print_one_log() can process a log.
One of possible mitigation would be to introduce a new lock in order to
make sure that no other series of printk() (either oom_kill_process() or
warn_alloc()) can append to printk() buffer when one series of printk()
(either oom_kill_process() or warn_alloc()) is already in progress.
Such serialization will also help obtaining kernel messages in readable
form.
---------- Pseudo code start ----------
retry:
if (mutex_trylock(&oom_lock)) {
mutex_lock(&oom_printk_lock);
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_printk_lock);
mutex_unlock(&oom_lock)
} else {
if (mutex_trylock(&oom_printk_lock)) {
atomic_inc(&printk_pending_logs);
mutex_unlock(&oom_printk_lock);
}
}
goto retry;
---------- Pseudo code end ----------
But this commit does not go that direction, for we don't want to
introduce a new lock dependency, and we unlikely be able to obtain
useful information even if we serialized oom_kill_process() and
warn_alloc().
Synchronous approach is prone to unexpected results (e.g. too late [1],
too frequent [2], overlooked [3]). As far as I know, warn_alloc() never
helped with providing information other than "something is going wrong".
I want to consider asynchronous approach which can obtain information
during stalls with possibly relevant threads (e.g. the owner of
oom_lock and kswapd-like threads) and serve as a trigger for actions
(e.g. turn on/off tracepoints, ask libvirt daemon to take a memory dump
of stalling KVM guest for diagnostic purpose).
This commit temporarily loses ability to report e.g. OOM lockup due to
unable to invoke the OOM killer due to !__GFP_FS allocation request.
But asynchronous approach will be able to detect such situation and emit
warning. Thus, let's remove warn_alloc().
[1] https://bugzilla.kernel.org/show_bug.cgi?id=192981
[2] http://lkml.kernel.org/r/CAM_iQpWuPVGc2ky8M-9yukECtS+zKjiDasNymX7rMcBjBFyM_A@mail.gmail.com
[3] commit
db73ee0d46379922 ("mm, vmscan: do not loop on too_many_isolated for ever"))
Link: http://lkml.kernel.org/r/1509017339-4802-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Cong Wang <xiyou.wangcong@gmail.com>
Reported-by: yuwang.yuwang <yuwang.yuwang@alibaba-inc.com>
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Johannes Weiner [Thu, 16 Nov 2017 01:38:34 +0000 (17:38 -0800)]
fs: fuse: account fuse_inode slab memory as reclaimable
Fuse inodes are currently included in the unreclaimable slab counts -
SUnreclaim in /proc/meminfo, slab_unreclaimable in /proc/vmstat and the
per-cgroup memory.stat. But they are reclaimable just like other
filesystems' inodes, and /proc/sys/vm/drop_caches frees them easily.
Mark the slab cache reclaimable.
Link: http://lkml.kernel.org/r/20171102202727.12539-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Thu, 16 Nov 2017 01:38:30 +0000 (17:38 -0800)]
mm, page_alloc: fix potential false positive in __zone_watermark_ok
Since commit
97a16fc82a7c ("mm, page_alloc: only enforce watermarks for
order-0 allocations"), __zone_watermark_ok() check for high-order
allocations will shortcut per-migratetype free list checks for
ALLOC_HARDER allocations, and return true as long as there's free page
of any migratetype. The intention is that ALLOC_HARDER can allocate
from MIGRATE_HIGHATOMIC free lists, while normal allocations can't.
However, as a side effect, the watermark check will then also return
true when there are pages only on the MIGRATE_ISOLATE list, or (prior to
CMA conversion to ZONE_MOVABLE) on the MIGRATE_CMA list. Since the
allocation cannot actually obtain isolated pages, and might not be able
to obtain CMA pages, this can result in a false positive.
The condition should be rare and perhaps the outcome is not a fatal one.
Still, it's better if the watermark check is correct. There also
shouldn't be a performance tradeoff here.
Link: http://lkml.kernel.org/r/20171102125001.23708-1-vbabka@suse.cz
Fixes: 97a16fc82a7c ("mm, page_alloc: only enforce watermarks for order-0 allocations")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shakeel Butt [Thu, 16 Nov 2017 01:38:26 +0000 (17:38 -0800)]
mm: mlock: remove lru_add_drain_all()
lru_add_drain_all() is not required by mlock() and it will drain
everything that has been cached at the time mlock is called. And that
is not really related to the memory which will be faulted in (and
cached) and mlocked by the syscall itself.
If anything lru_add_drain_all() should be called _after_ pages have been
mlocked and faulted in but even that is not strictly needed because
those pages would get to the appropriate LRUs lazily during the reclaim
path. Moreover follow_page_pte (gup) will drain the local pcp LRU
cache.
On larger machines the overhead of lru_add_drain_all() in mlock() can be
significant when mlocking data already in memory. We have observed high
latency in mlock() due to lru_add_drain_all() when the users were
mlocking in memory tmpfs files.
[mhocko@suse.com: changelog fix]
Link: http://lkml.kernel.org/r/20171019222507.2894-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kemi Wang [Thu, 16 Nov 2017 01:38:22 +0000 (17:38 -0800)]
mm, sysctl: make NUMA stats configurable
This is the second step which introduces a tunable interface that allow
numa stats configurable for optimizing zone_statistics(), as suggested
by Dave Hansen and Ying Huang.
=========================================================================
When page allocation performance becomes a bottleneck and you can
tolerate some possible tool breakage and decreased numa counter
precision, you can do:
echo 0 > /proc/sys/vm/numa_stat
In this case, numa counter update is ignored. We can see about
*4.8%*(185->176) drop of cpu cycles per single page allocation and
reclaim on Jesper's page_bench01 (single thread) and *8.1%*(343->315)
drop of cpu cycles per single page allocation and reclaim on Jesper's
page_bench03 (88 threads) running on a 2-Socket Broadwell-based server
(88 threads, 126G memory).
Benchmark link provided by Jesper D Brouer (increase loop times to
10000000):
https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench
=========================================================================
When page allocation performance is not a bottleneck and you want all
tooling to work, you can do:
echo 1 > /proc/sys/vm/numa_stat
This is system default setting.
Many thanks to Michal Hocko, Dave Hansen, Ying Huang and Vlastimil Babka
for comments to help improve the original patch.
[keescook@chromium.org: make sure mutex is a global static]
Link: http://lkml.kernel.org/r/20171107213809.GA4314@beast
Link: http://lkml.kernel.org/r/1508290927-8518-1-git-send-email-kemi.wang@intel.com
Signed-off-by: Kemi Wang <kemi.wang@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Suggested-by: Ying Huang <ying.huang@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christopher Lameter <cl@linux.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
weiping zhang [Thu, 16 Nov 2017 01:38:18 +0000 (17:38 -0800)]
shmem: convert shmem_init_inodecache() to void
shmem_inode_cachep was created with SLAB_PANIC flag and
shmem_init_inodecache() never returns non-zero, so convert this
function to return void.
Link: http://lkml.kernel.org/r/20170909124542.GA35224@bogon.didichuxing.com
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Otto Ebeling [Thu, 16 Nov 2017 01:38:14 +0000 (17:38 -0800)]
Unify migrate_pages and move_pages access checks
Commit
197e7e521384 ("Sanitize 'move_pages()' permission checks") fixed
a security issue I reported in the move_pages syscall, and made it so
that you can't act on set-uid processes unless you have the
CAP_SYS_PTRACE capability.
Unify the access check logic of migrate_pages to match the new behavior
of move_pages. We discussed this a bit in the security@ list and
thought it'd be good for consistency even though there's no evident
security impact. The NUMA node access checks are left intact and
require CAP_SYS_NICE as before.
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1710011830320.6333@lakka.kapsi.fi
Signed-off-by: Otto Ebeling <otto.ebeling@iki.fi>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:38:10 +0000 (17:38 -0800)]
mm, pagevec: rename pagevec drained field
According to Vlastimil Babka, the drained field in pagevec is
potentially misleading because it might be interpreted as draining this
pagevec instead of the percpu lru pagevecs. Rename the field for
clarity.
Link: http://lkml.kernel.org/r/20171019093346.ylahzdpzmoriyf4v@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vlastimil Babka [Thu, 16 Nov 2017 01:38:07 +0000 (17:38 -0800)]
mm, page_alloc: simplify list handling in rmqueue_bulk()
rmqueue_bulk() fills an empty pcplist with pages from the free list. It
tries to preserve increasing order by pfn to the caller, because it
leads to better performance with some I/O controllers, as explained in
commit
e084b2d95e48 ("page-allocator: preserve PFN ordering when
__GFP_COLD is set").
To preserve the order, it's sufficient to add pages to the tail of the
list as they are retrieved. The current code instead adds to the head
of the list, but then updates the list head pointer to the last added
page, in each step. This does result in the same order, but is
needlessly confusing and potentially wasteful, with no apparent benefit.
This patch simplifies the code and adjusts comment accordingly.
Link: http://lkml.kernel.org/r/f6505442-98a9-12e4-b2cd-0fa83874c159@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:38:03 +0000 (17:38 -0800)]
mm: remove __GFP_COLD
As the page free path makes no distinction between cache hot and cold
pages, there is no real useful ordering of pages in the free list that
allocation requests can take advantage of. Juding from the users of
__GFP_COLD, it is likely that a number of them are the result of copying
other sites instead of actually measuring the impact. Remove the
__GFP_COLD parameter which simplifies a number of paths in the page
allocator.
This is potentially controversial but bear in mind that the size of the
per-cpu pagelists versus modern cache sizes means that the whole per-cpu
list can often fit in the L3 cache. Hence, there is only a potential
benefit for microbenchmarks that alloc/free pages in a tight loop. It's
even worse when THP is taken into account which has little or no chance
of getting a cache-hot page as the per-cpu list is bypassed and the
zeroing of multiple pages will thrash the cache anyway.
The truncate microbenchmarks are not shown as this patch affects the
allocation path and not the free path. A page fault microbenchmark was
tested but it showed no sigificant difference which is not surprising
given that the __GFP_COLD branches are a miniscule percentage of the
fault path.
Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:37:59 +0000 (17:37 -0800)]
mm: remove cold parameter from free_hot_cold_page*
Most callers users of free_hot_cold_page claim the pages being released
are cache hot. The exception is the page reclaim paths where it is
likely that enough pages will be freed in the near future that the
per-cpu lists are going to be recycled and the cache hotness information
is lost. As no one really cares about the hotness of pages being
released to the allocator, just ditch the parameter.
The APIs are renamed to indicate that it's no longer about hot/cold
pages. It should also be less confusing as there are subtle differences
between them. __free_pages drops a reference and frees a page when the
refcount reaches zero. free_hot_cold_page handled pages whose refcount
was already zero which is non-obvious from the name. free_unref_page
should be more obvious.
No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.
[mgorman@techsingularity.net: add pages to head, not tail]
Link: http://lkml.kernel.org/r/20171019154321.qtpzaeftoyyw4iey@techsingularity.net
Link: http://lkml.kernel.org/r/20171018075952.10627-8-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:37:55 +0000 (17:37 -0800)]
mm: remove cold parameter for release_pages
All callers of release_pages claim the pages being released are cache
hot. As no one cares about the hotness of pages being released to the
allocator, just ditch the parameter.
No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.
Link: http://lkml.kernel.org/r/20171018075952.10627-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:37:52 +0000 (17:37 -0800)]
mm, pagevec: remove cold parameter for pagevecs
Every pagevec_init user claims the pages being released are hot even in
cases where it is unlikely the pages are hot. As no one cares about the
hotness of pages being released to the allocator, just ditch the
parameter.
No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.
Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:37:48 +0000 (17:37 -0800)]
mm: only drain per-cpu pagevecs once per pagevec usage
When a pagevec is initialised on the stack, it is generally used
multiple times over a range of pages, looking up entries and then
releasing them. On each pagevec_release, the per-cpu deferred LRU
pagevecs are drained on the grounds the page being released may be on
those queues and the pages may be cache hot. In many cases only the
first drain is necessary as it's unlikely that the range of pages being
walked is racing against LRU addition. Even if there is such a race,
the impact is marginal where as constantly redraining the lru pagevecs
costs.
This patch ensures that pagevec is only drained once in a given
lifecycle without increasing the cache footprint of the pagevec
structure. Only sparsetruncate tiny is shown here as large files have
many exceptional entries and calls pagecache_release less frequently.
sparsetruncate (tiny)
4.14.0-rc4 4.14.0-rc4
batchshadow-v1r1 onedrain-v1r1
Min Time 141.00 ( 0.00%) 141.00 ( 0.00%)
1st-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%)
2nd-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%)
3rd-qrtle Time 143.00 ( 0.00%) 143.00 ( 0.00%)
Max-90% Time 144.00 ( 0.00%) 144.00 ( 0.00%)
Max-95% Time 146.00 ( 0.00%) 145.00 ( 0.68%)
Max-99% Time 198.00 ( 0.00%) 194.00 ( 2.02%)
Max Time 254.00 ( 0.00%) 208.00 ( 18.11%)
Amean Time 145.12 ( 0.00%) 144.30 ( 0.56%)
Stddev Time 12.74 ( 0.00%) 9.62 ( 24.49%)
Coeff Time 8.78 ( 0.00%) 6.67 ( 24.06%)
Best99%Amean Time 144.29 ( 0.00%) 143.82 ( 0.32%)
Best95%Amean Time 142.68 ( 0.00%) 142.31 ( 0.26%)
Best90%Amean Time 142.52 ( 0.00%) 142.19 ( 0.24%)
Best75%Amean Time 142.26 ( 0.00%) 141.98 ( 0.20%)
Best50%Amean Time 141.90 ( 0.00%) 141.71 ( 0.13%)
Best25%Amean Time 141.80 ( 0.00%) 141.43 ( 0.26%)
The impact on bonnie is marginal and within the noise because a
significant percentage of the file being truncated has been reclaimed
and consists of shadow entries which reduce the hotness of the
pagevec_release path.
Link: http://lkml.kernel.org/r/20171018075952.10627-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:37:44 +0000 (17:37 -0800)]
mm, truncate: remove all exceptional entries from pagevec under one lock
During truncate each entry in a pagevec is checked to see if it is an
exceptional entry and if so, the shadow entry is cleaned up. This is
potentially expensive as multiple entries for a mapping locks/unlocks
the tree lock. This batches the operation such that any exceptional
entries removed from a pagevec only acquire the mapping tree lock once.
The corner case where this is more expensive is where there is only one
exceptional entry but this is unlikely due to temporal locality and how
it affects LRU ordering. Note that for truncations of small files
created recently, this patch should show no gain because it only batches
the handling of exceptional entries.
sparsetruncate (large)
4.14.0-rc4 4.14.0-rc4
pickhelper-v1r1 batchshadow-v1r1
Min Time 38.00 ( 0.00%) 27.00 ( 28.95%)
1st-qrtle Time 40.00 ( 0.00%) 28.00 ( 30.00%)
2nd-qrtle Time 44.00 ( 0.00%) 41.00 ( 6.82%)
3rd-qrtle Time 146.00 ( 0.00%) 147.00 ( -0.68%)
Max-90% Time 153.00 ( 0.00%) 153.00 ( 0.00%)
Max-95% Time 155.00 ( 0.00%) 156.00 ( -0.65%)
Max-99% Time 181.00 ( 0.00%) 171.00 ( 5.52%)
Amean Time 93.04 ( 0.00%) 88.43 ( 4.96%)
Best99%Amean Time 92.08 ( 0.00%) 86.13 ( 6.46%)
Best95%Amean Time 89.19 ( 0.00%) 83.13 ( 6.80%)
Best90%Amean Time 85.60 ( 0.00%) 79.15 ( 7.53%)
Best75%Amean Time 72.95 ( 0.00%) 65.09 ( 10.78%)
Best50%Amean Time 39.86 ( 0.00%) 28.20 ( 29.25%)
Best25%Amean Time 39.44 ( 0.00%) 27.70 ( 29.77%)
bonnie
4.14.0-rc4 4.14.0-rc4
pickhelper-v1r1 batchshadow-v1r1
Hmean SeqCreate ops 71.92 ( 0.00%) 76.78 ( 6.76%)
Hmean SeqCreate read 42.42 ( 0.00%) 45.01 ( 6.10%)
Hmean SeqCreate del 26519.88 ( 0.00%) 27191.87 ( 2.53%)
Hmean RandCreate ops 71.92 ( 0.00%) 76.95 ( 7.00%)
Hmean RandCreate read 44.44 ( 0.00%) 49.23 ( 10.78%)
Hmean RandCreate del 24948.62 ( 0.00%) 24764.97 ( -0.74%)
Truncation of a large number of files shows a substantial gain with 99%
of files being truncated 6.46% faster. bonnie shows a modest gain of
2.53%
[jack@suse.cz: fix truncate_exceptional_pvec_entries()]
Link: http://lkml.kernel.org/r/20171108164226.26788-1-jack@suse.cz
Link: http://lkml.kernel.org/r/20171018075952.10627-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:37:41 +0000 (17:37 -0800)]
mm, truncate: do not check mapping for every page being truncated
During truncation, the mapping has already been checked for shmem and
dax so it's known that workingset_update_node is required.
This patch avoids the checks on mapping for each page being truncated.
In all other cases, a lookup helper is used to determine if
workingset_update_node() needs to be called. The one danger is that the
API is slightly harder to use as calling workingset_update_node directly
without checking for dax or shmem mappings could lead to surprises.
However, the API rarely needs to be used and hopefully the comment is
enough to give people the hint.
sparsetruncate (tiny)
4.14.0-rc4 4.14.0-rc4
oneirq-v1r1 pickhelper-v1r1
Min Time 141.00 ( 0.00%) 140.00 ( 0.71%)
1st-qrtle Time 142.00 ( 0.00%) 141.00 ( 0.70%)
2nd-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%)
3rd-qrtle Time 143.00 ( 0.00%) 143.00 ( 0.00%)
Max-90% Time 144.00 ( 0.00%) 144.00 ( 0.00%)
Max-95% Time 147.00 ( 0.00%) 145.00 ( 1.36%)
Max-99% Time 195.00 ( 0.00%) 191.00 ( 2.05%)
Max Time 230.00 ( 0.00%) 205.00 ( 10.87%)
Amean Time 144.37 ( 0.00%) 143.82 ( 0.38%)
Stddev Time 10.44 ( 0.00%) 9.00 ( 13.74%)
Coeff Time 7.23 ( 0.00%) 6.26 ( 13.41%)
Best99%Amean Time 143.72 ( 0.00%) 143.34 ( 0.26%)
Best95%Amean Time 142.37 ( 0.00%) 142.00 ( 0.26%)
Best90%Amean Time 142.19 ( 0.00%) 141.85 ( 0.24%)
Best75%Amean Time 141.92 ( 0.00%) 141.58 ( 0.24%)
Best50%Amean Time 141.69 ( 0.00%) 141.31 ( 0.27%)
Best25%Amean Time 141.38 ( 0.00%) 140.97 ( 0.29%)
As you'd expect, the gain is marginal but it can be detected. The
differences in bonnie are all within the noise which is not surprising
given the impact on the microbenchmark.
radix_tree_update_node_t is a callback for some radix operations that
optionally passes in a private field. The only user of the callback is
workingset_update_node and as it no longer requires a mapping, the
private field is removed.
Link: http://lkml.kernel.org/r/20171018075952.10627-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Thu, 16 Nov 2017 01:37:37 +0000 (17:37 -0800)]
mm, page_alloc: enable/disable IRQs once when freeing a list of pages
Patch series "Follow-up for speed up page cache truncation", v2.
This series is a follow-on for Jan Kara's series "Speed up page cache
truncation" series. We both ended up looking at the same problem but
saw different problems based on the same data. This series builds upon
his work.
A variety of workloads were compared on four separate machines but each
machine showed gains albeit at different levels. Minimally, some of the
differences are due to NUMA where truncating data from a remote node is
slower than a local node. The workloads checked were
o sparse truncate microbenchmark, tiny
o sparse truncate microbenchmark, large
o reaim-io disk workfile
o dbench4 (modified by mmtests to produce more stable results)
o filebench varmail configuration for small memory size
o bonnie, directory operations, working set size 2*RAM
reaim-io, dbench and filebench all showed minor gains. Truncation does
not dominate those workloads but were tested to ensure no other
regressions. They will not be reported further.
The sparse truncate microbench was written by Jan. It creates a number
of files and then times how long it takes to truncate each one. The
"tiny" configuraiton creates a number of files that easily fits in
memory and times how long it takes to truncate files with page cache.
The large configuration uses enough files to have data that is twice the
size of memory and so timings there include truncating page cache and
working set shadow entries in the radix tree.
Patches 1-4 are the most relevant parts of this series. Patches 5-8 are
optional as they are deleting code that is essentially useless but has a
negligible performance impact.
The changelogs have more information on performance but just for bonnie
delete options, the main comparison is
bonnie
4.14.0-rc5 4.14.0-rc5 4.14.0-rc5
jan-v2 vanilla mel-v2
Hmean SeqCreate ops 76.20 ( 0.00%) 75.80 ( -0.53%) 76.80 ( 0.79%)
Hmean SeqCreate read 85.00 ( 0.00%) 85.00 ( 0.00%) 85.00 ( 0.00%)
Hmean SeqCreate del 13752.31 ( 0.00%) 12090.23 ( -12.09%) 15304.84 ( 11.29%)
Hmean RandCreate ops 76.00 ( 0.00%) 75.60 ( -0.53%) 77.00 ( 1.32%)
Hmean RandCreate read 96.80 ( 0.00%) 96.80 ( 0.00%) 97.00 ( 0.21%)
Hmean RandCreate del 13233.75 ( 0.00%) 11525.35 ( -12.91%) 14446.61 ( 9.16%)
Jan's series is the baseline and the vanilla kernel is 12% slower where
as this series on top gains another 11%. This is from a different
machine than the data in the changelogs but the detailed data was not
collected as there was no substantial change in v2.
This patch (of 8):
Freeing a list of pages current enables/disables IRQs for each page
freed. This patch splits freeing a list of pages into two operations --
preparing the pages for freeing and the actual freeing. This is a
tradeoff - we're taking two passes of the list to free in exchange for
avoiding multiple enable/disable of IRQs.
sparsetruncate (tiny)
4.14.0-rc4 4.14.0-rc4
janbatch-v1r1 oneirq-v1r1
Min Time 149.00 ( 0.00%) 141.00 ( 5.37%)
1st-qrtle Time 150.00 ( 0.00%) 142.00 ( 5.33%)
2nd-qrtle Time 151.00 ( 0.00%) 142.00 ( 5.96%)
3rd-qrtle Time 151.00 ( 0.00%) 143.00 ( 5.30%)
Max-90% Time 153.00 ( 0.00%) 144.00 ( 5.88%)
Max-95% Time 155.00 ( 0.00%) 147.00 ( 5.16%)
Max-99% Time 201.00 ( 0.00%) 195.00 ( 2.99%)
Max Time 236.00 ( 0.00%) 230.00 ( 2.54%)
Amean Time 152.65 ( 0.00%) 144.37 ( 5.43%)
Stddev Time 9.78 ( 0.00%) 10.44 ( -6.72%)
Coeff Time 6.41 ( 0.00%) 7.23 ( -12.84%)
Best99%Amean Time 152.07 ( 0.00%) 143.72 ( 5.50%)
Best95%Amean Time 150.75 ( 0.00%) 142.37 ( 5.56%)
Best90%Amean Time 150.59 ( 0.00%) 142.19 ( 5.58%)
Best75%Amean Time 150.36 ( 0.00%) 141.92 ( 5.61%)
Best50%Amean Time 150.04 ( 0.00%) 141.69 ( 5.56%)
Best25%Amean Time 149.85 ( 0.00%) 141.38 ( 5.65%)
With a tiny number of files, each file truncated has resident page cache
and it shows that time to truncate is roughtly 5-6% with some minor
jitter.
4.14.0-rc4 4.14.0-rc4
janbatch-v1r1 oneirq-v1r1
Hmean SeqCreate ops 65.27 ( 0.00%) 81.86 ( 25.43%)
Hmean SeqCreate read 39.48 ( 0.00%) 47.44 ( 20.16%)
Hmean SeqCreate del 24963.95 ( 0.00%) 26319.99 ( 5.43%)
Hmean RandCreate ops 65.47 ( 0.00%) 82.01 ( 25.26%)
Hmean RandCreate read 42.04 ( 0.00%) 51.75 ( 23.09%)
Hmean RandCreate del 23377.66 ( 0.00%) 23764.79 ( 1.66%)
As expected, there is a small gain for the delete operation.
[mgorman@techsingularity.net: use page_private and set_page_private helpers]
Link: http://lkml.kernel.org/r/20171018101547.mjycw7zreb66jzpa@techsingularity.net
Link: http://lkml.kernel.org/r/20171018075952.10627-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Jan Kara <jack@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:37:33 +0000 (17:37 -0800)]
mm: batch radix tree operations when truncating pages
Currently we remove pages from the radix tree one by one. To speed up
page cache truncation, lock several pages at once and free them in one
go. This allows us to batch radix tree operations in a more efficient
way and also save round-trips on mapping->tree_lock. As a result we
gain about 20% speed improvement in page cache truncation.
Data from a simple benchmark timing 10000 truncates of 1024 pages (on
ext4 on ramdisk but the filesystem is barely visible in the profiles).
The range shows 1% and 95% percentiles of the measured times:
4.14-rc2 4.14-rc2 + batched truncation
248-256 209-219
249-258 209-217
248-255 211-239
248-255 209-217
247-256 210-218
[jack@suse.cz: convert delete_from_page_cache_batch() to pagevec]
Link: http://lkml.kernel.org/r/20171018111648.13714-1-jack@suse.cz
[akpm@linux-foundation.org: move struct pagevec forward declaration to top-of-file]
Link: http://lkml.kernel.org/r/20171010151937.26984-8-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:37:29 +0000 (17:37 -0800)]
mm: factor out checks and accounting from __delete_from_page_cache()
Move checks and accounting updates from __delete_from_page_cache() into
a separate function. We will reuse it when batching page cache
truncation operations.
Link: http://lkml.kernel.org/r/20171010151937.26984-7-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:37:26 +0000 (17:37 -0800)]
mm: move clearing of page->mapping to page_cache_tree_delete()
Clearing of page->mapping makes sense in page_cache_tree_delete() as
well and it will help us with batching things this way.
Link: http://lkml.kernel.org/r/20171010151937.26984-6-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:37:22 +0000 (17:37 -0800)]
mm: move accounting updates before page_cache_tree_delete()
Move updates of various counters before page_cache_tree_delete() call.
It will be easier to batch things this way and there is no difference
whether the counters get updated before or after removal from the radix
tree.
Link: http://lkml.kernel.org/r/20171010151937.26984-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:37:18 +0000 (17:37 -0800)]
mm: factor out page cache page freeing into a separate function
Factor out page freeing from delete_from_page_cache() into a separate
function. We will need to call the same when batching pagecache
deletion operations.
invalidate_complete_page2() and replace_page_cache_page() might want to
call this function as well however they currently don't seem to handle
THPs so it's unnecessary for them to take the hit of checking whether a
page is THP or not.
Link: http://lkml.kernel.org/r/20171010151937.26984-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:37:15 +0000 (17:37 -0800)]
mm: refactor truncate_complete_page()
Move call of delete_from_page_cache() and page->mapping check out of
truncate_complete_page() into the single caller - truncate_inode_page().
Also move page_mapped() check into truncate_complete_page(). That way
it will be easier to batch operations.
Also rename truncate_complete_page() to truncate_cleanup_page().
Link: http://lkml.kernel.org/r/20171010151937.26984-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:37:11 +0000 (17:37 -0800)]
mm: speed up cancel_dirty_page() for clean pages
Patch series "Speed up page cache truncation", v1.
When rebasing our enterprise distro to a newer kernel (from 4.4 to 4.12)
we have noticed a regression in bonnie++ benchmark when deleting files.
Eventually we have tracked this down to a fact that page cache
truncation got slower by about 10%. There were both gains and losses in
the above interval of kernels but we have been able to identify that
commit
83929372f629 ("filemap: prepare find and delete operations for
huge pages") caused about 10% regression on its own.
After some investigation it didn't seem easily possible to fix the
regression while maintaining the THP in page cache functionality so
we've decided to optimize the page cache truncation path instead to make
up for the change. This series is a result of that effort.
Patch 1 is an easy speedup of cancel_dirty_page(). Patches 2-6 refactor
page cache truncation code so that it is easier to batch radix tree
operations. Patch 7 implements batching of deletes from the radix tree
which more than makes up for the original regression.
This patch (of 7):
cancel_dirty_page() does quite some work even for clean pages (fetching
of mapping, locking of memcg, atomic bit op on page flags) so it
accounts for ~2.5% of cost of truncation of a clean page. That is not
much but still dumb for something we don't need at all. Check whether a
page is actually dirty and avoid any work if not.
Link: http://lkml.kernel.org/r/20171010151937.26984-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Colin Ian King [Thu, 16 Nov 2017 01:37:08 +0000 (17:37 -0800)]
drivers/block/zram/zram_drv.c: make zram_page_end_io() static
zram_page_end_io() is local to the source and does not need to be in
global scope, so make it static.
Cleans up sparse warning:
symbol 'zram_page_end_io' was not declared. Should it be static?
Link: http://lkml.kernel.org/r/20171016173336.20320-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kees Cook [Thu, 16 Nov 2017 01:37:04 +0000 (17:37 -0800)]
mm/page-writeback.c: convert timers to use timer_setup()
In preparation for unconditionally passing the struct timer_list pointer
to all timer callbacks, switch to using the new timer_setup() and
from_timer() to pass the timer pointer explicitly.
Link: http://lkml.kernel.org/r/20171016225913.GA99214@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Laszlo Toth [Thu, 16 Nov 2017 01:37:00 +0000 (17:37 -0800)]
mm, soft_offline: improve hugepage soft offlining error log
On a failed attempt, we get the following entry: soft offline: 0x3c0000:
migration failed 1, type
17ffffc0008008 (uptodate|head)
Make this more specific to be straightforward and to follow other error
log formats in soft_offline_huge_page().
Link: http://lkml.kernel.org/r/20171016171757.GA3018@ubuntu-desk-vm
Signed-off-by: Laszlo Toth <laszlth@gmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Thu, 16 Nov 2017 01:36:56 +0000 (17:36 -0800)]
userfaultfd: use mmgrab instead of open-coded increment of mm_count
Link: http://lkml.kernel.org/r/1508132478-7738-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Aaron Lu [Thu, 16 Nov 2017 01:36:53 +0000 (17:36 -0800)]
mm/page_alloc: make sure __rmqueue() etc are always inline
__rmqueue(), __rmqueue_fallback(), __rmqueue_smallest() and
__rmqueue_cma_fallback() are all in page allocator's hot path and better
be finished as soon as possible. One way to make them faster is by making
them inline. But as Andrew Morton and Andi Kleen pointed out:
https://lkml.org/lkml/2017/10/10/1252
https://lkml.org/lkml/2017/10/10/1279
To make sure they are inlined, we should use __always_inline for them.
With the will-it-scale/page_fault1/process benchmark, when using nr_cpu
processes to stress buddy, the results for will-it-scale.processes with
and without the patch are:
On a 2-sockets Intel-Skylake machine:
compiler base head
gcc-4.4.7
6496131 6911823 +6.4%
gcc-4.9.4
7225110 7731072 +7.0%
gcc-5.4.1
7054224 7688146 +9.0%
gcc-6.2.0
7059794 7651675 +8.4%
On a 4-sockets Intel-Skylake machine:
compiler base head
gcc-4.4.7
13162890 13508193 +2.6%
gcc-4.9.4
14997463 15484353 +3.2%
gcc-5.4.1
14708711 15449805 +5.0%
gcc-6.2.0
14574099 15349204 +5.3%
The above 4 compilers are used because I've done the tests through
Intel's Linux Kernel Performance(LKP) infrastructure and they are the
available compilers there.
The benefit being less on 4 sockets machine is due to the lock
contention there(perf-profile/native_queued_spin_lock_slowpath=81%) is
less severe than on the 2 sockets machine(85%).
What the benchmark does is: it forks nr_cpu processes and then each
process does the following:
1 mmap() 128M anonymous space;
2 writes to each page there to trigger actual page allocation;
3 munmap() it.
in a loop.
https://github.com/antonblanchard/will-it-scale/blob/master/tests/page_fault1.c
Binary size wise, I have locally built them with different compilers:
[aaron@aaronlu obj]$ size */*/mm/page_alloc.o
text data bss dec hex filename
37409 9904 8524 55837 da1d gcc-4.9.4/base/mm/page_alloc.o
38273 9904 8524 56701 dd7d gcc-4.9.4/head/mm/page_alloc.o
37465 9840 8428 55733 d9b5 gcc-5.5.0/base/mm/page_alloc.o
38169 9840 8428 56437 dc75 gcc-5.5.0/head/mm/page_alloc.o
37573 9840 8428 55841 da21 gcc-6.4.0/base/mm/page_alloc.o
38261 9840 8428 56529 dcd1 gcc-6.4.0/head/mm/page_alloc.o
36863 9840 8428 55131 d75b gcc-7.2.0/base/mm/page_alloc.o
37711 9840 8428 55979 daab gcc-7.2.0/head/mm/page_alloc.o
Text size increased about 800 bytes for mm/page_alloc.o.
[aaron@aaronlu obj]$ size */*/vmlinux
text data bss dec hex filename
10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/base/vmlinux
10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/head/vmlinux
10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/base/vmlinux
10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/head/vmlinux
10094546 5836696 17715200 33646442 201676a gcc-6.4.0/base/vmlinux
10094546 5836696 17715200 33646442 201676a gcc-6.4.0/head/vmlinux
10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/base/vmlinux
10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/head/vmlinux
Text size for vmlinux has no change though, probably due to function
alignment.
Link: http://lkml.kernel.org/r/20171013063111.GA26032@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:48 +0000 (17:36 -0800)]
sparc64: optimize struct page zeroing
Add an optimized mm_zero_struct_page(), so struct page's are zeroed
without calling memset(). We do eight to ten regular stores based on
the size of struct page. Compiler optimizes out the conditions of
switch() statement.
SPARC-M6 with 15T of memory, single thread performance:
BASE FIX OPTIMIZED_FIX
bootmem_init 28.440467985s 2.305674818s 2.305161615s
free_area_init_nodes 202.845901673s 225.343084508s 172.556506560s
--------------------------------------------
Total 231.286369658s 227.648759326s 174.861668175s
BASE: current linux
FIX: This patch series without "optimized struct page zeroing"
OPTIMIZED_FIX: This patch series including the current patch.
bootmem_init() is where memory for struct pages is zeroed during
allocation. Note, about two seconds in this function is a fixed time:
it does not increase as memory is increased.
Link: http://lkml.kernel.org/r/20171013173214.27300-11-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:44 +0000 (17:36 -0800)]
mm: stop zeroing memory during allocation in vmemmap
vmemmap_alloc_block() will no longer zero the block, so zero memory at
its call sites for everything except struct pages. Struct page memory
is zero'd by struct page initialization.
Replace allocators in sparse-vmemmap to use the non-zeroing version.
So, we will get the performance improvement by zeroing the memory in
parallel when struct pages are zeroed.
Add struct page zeroing as a part of initialization of other fields in
__init_single_page().
This single thread performance collected on: Intel(R) Xeon(R) CPU E7-8895
v3 @ 2.60GHz with 1T of memory (
268400646 pages in 8 nodes):
BASE FIX
sparse_init 11.244671836s 0.007199623s
zone_sizes_init 4.879775891s 8.355182299s
--------------------------
Total 16.124447727s 8.362381922s
sparse_init is where memory for struct pages is zeroed, and the zeroing
part is moved later in this patch into __init_single_page(), which is
called from zone_sizes_init().
[akpm@linux-foundation.org: make vmemmap_alloc_block_zero() private to sparse-vmemmap.c]
Link: http://lkml.kernel.org/r/20171013173214.27300-10-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Will Deacon [Thu, 16 Nov 2017 01:36:40 +0000 (17:36 -0800)]
arm64/mm/kasan: don't use vmemmap_populate() to initialize shadow
The kasan shadow is currently mapped using vmemmap_populate() since that
provides a semi-convenient way to map pages into init_top_pgt. However,
since that no longer zeroes the mapped pages, it is not suitable for
kasan, which requires zeroed shadow memory.
Add kasan_populate_shadow() interface and use it instead of
vmemmap_populate(). Besides, this allows us to take advantage of
gigantic pages and use them to populate the shadow, which should save us
some memory wasted on page tables and reduce TLB pressure.
Link: http://lkml.kernel.org/r/20171103185147.2688-3-pasha.tatashin@oracle.com
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Ryabinin [Thu, 16 Nov 2017 01:36:35 +0000 (17:36 -0800)]
x86/mm/kasan: don't use vmemmap_populate() to initialize shadow
The kasan shadow is currently mapped using vmemmap_populate() since that
provides a semi-convenient way to map pages into init_top_pgt. However,
since that no longer zeroes the mapped pages, it is not suitable for
kasan, which requires zeroed shadow memory.
Add kasan_populate_shadow() interface and use it instead of
vmemmap_populate(). Besides, this allows us to take advantage of
gigantic pages and use them to populate the shadow, which should save us
some memory wasted on page tables and reduce TLB pressure.
Link: http://lkml.kernel.org/r/20171103185147.2688-2-pasha.tatashin@oracle.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:31 +0000 (17:36 -0800)]
mm: zero reserved and unavailable struct pages
Some memory is reserved but unavailable: not present in memblock.memory
(because not backed by physical pages), but present in memblock.reserved.
Such memory has backing struct pages, but they are not initialized by
going through __init_single_page().
In some cases these struct pages are accessed even if they do not
contain any data. One example is page_to_pfn() might access page->flags
if this is where section information is stored (CONFIG_SPARSEMEM,
SECTION_IN_PAGE_FLAGS).
One example of such memory: trim_low_memory_range() unconditionally
reserves from pfn 0, but e820__memblock_setup() might provide the
exiting memory from pfn 1 (i.e. KVM).
Since struct pages are zeroed in __init_single_page(), and not during
allocation time, we must zero such struct pages explicitly.
The patch involves adding a new memblock iterator:
for_each_resv_unavail_range(i, p_start, p_end)
Which iterates through reserved && !memory lists, and we zero struct pages
explicitly by calling mm_zero_struct_page().
===
Here is more detailed example of problem that this patch is addressing:
Run tested on qemu with the following arguments:
-enable-kvm -cpu kvm64 -m 512 -smp 2
This patch reports that there are 98 unavailable pages.
They are: pfn 0 and pfns in range [159, 255].
Note, trim_low_memory_range() reserves only pfns in range [0, 15], it does
not reserve [159, 255] ones.
e820__memblock_setup() reports linux that the following physical ranges are
available:
[1 , 158]
[256, 130783]
Notice, that exactly unavailable pfns are missing!
Now, lets check what we have in zone 0: [1, 131039]
pfn 0, is not part of the zone, but pfns [1, 158], are.
However, the bigger problem we have if we do not initialize these struct
pages is with memory hotplug. Because, that path operates at 2M
boundaries (section_nr). And checks if 2M range of pages is hot
removable. It starts with first pfn from zone, rounds it down to 2M
boundary (sturct pages are allocated at 2M boundaries when vmemmap is
created), and checks if that section is hot removable. In this case
start with pfn 1 and convert it down to pfn 0. Later pfn is converted
to struct page, and some fields are checked. Now, if we do not zero
struct pages, we get unpredictable results.
In fact when CONFIG_VM_DEBUG is enabled, and we explicitly set all
vmemmap memory to ones, the following panic is observed with kernel test
without this patch applied:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: is_pageblock_removable_nolock+0x35/0x90
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT
...
task:
ffff88001f4e2900 task.stack:
ffffc90000314000
RIP: 0010:is_pageblock_removable_nolock+0x35/0x90
Call Trace:
? is_mem_section_removable+0x5a/0xd0
show_mem_removable+0x6b/0xa0
dev_attr_show+0x1b/0x50
sysfs_kf_seq_show+0xa1/0x100
kernfs_seq_show+0x22/0x30
seq_read+0x1ac/0x3a0
kernfs_fop_read+0x36/0x190
? security_file_permission+0x90/0xb0
__vfs_read+0x16/0x30
vfs_read+0x81/0x130
SyS_read+0x44/0xa0
entry_SYSCALL_64_fastpath+0x1f/0xbd
Link: http://lkml.kernel.org/r/20171013173214.27300-7-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:27 +0000 (17:36 -0800)]
mm: define memblock_virt_alloc_try_nid_raw
* A new variant of memblock_virt_alloc_* allocations:
memblock_virt_alloc_try_nid_raw()
- Does not zero the allocated memory
- Does not panic if request cannot be satisfied
* optimize early system hash allocations
Clients can call alloc_large_system_hash() with flag: HASH_ZERO to
specify that memory that was allocated for system hash needs to be
zeroed, otherwise the memory does not need to be zeroed, and client will
initialize it.
If memory does not need to be zero'd, call the new
memblock_virt_alloc_raw() interface, and thus improve the boot
performance.
* debug for raw alloctor
When CONFIG_DEBUG_VM is enabled, this patch sets all the memory that is
returned by memblock_virt_alloc_try_nid_raw() to ones to ensure that no
places excpect zeroed memory.
Link: http://lkml.kernel.org/r/20171013173214.27300-6-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:22 +0000 (17:36 -0800)]
sparc64: simplify vmemmap_populate
Remove duplicating code by using common functions vmemmap_pud_populate
and vmemmap_pgd_populate.
Link: http://lkml.kernel.org/r/20171013173214.27300-5-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:18 +0000 (17:36 -0800)]
sparc64/mm: set fields in deferred pages
Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),
flags and other fields in "struct page"es are never changed prior to
first initializing struct pages by going through __init_single_page().
With deferred struct page feature enabled there is a case where we set
some fields prior to initializing:
mem_init() {
register_page_bootmem_info();
free_all_bootmem();
...
}
When register_page_bootmem_info() is called only non-deferred struct
pages are initialized. But, this function goes through some reserved
pages which might be part of the deferred, and thus are not yet
initialized.
mem_init
register_page_bootmem_info
register_page_bootmem_info_node
get_page_bootmem
.. setting fields here ..
such as: page->freelist = (void *)type;
free_all_bootmem()
free_low_memory_core_early()
for_each_reserved_mem_region()
reserve_bootmem_region()
init_reserved_page() <- Only if this is deferred reserved page
__init_single_pfn()
__init_single_page()
memset(0) <-- Loose the set fields here
We end up with similar issue as in the previous patch, where currently
we do not observe problem as memory is zeroed. But, if flag asserts are
changed we can start hitting issues.
Also, because in this patch series we will stop zeroing struct page
memory during allocation, we must make sure that struct pages are
properly initialized prior to using them.
The deferred-reserved pages are initialized in free_all_bootmem().
Therefore, the fix is to switch the above calls.
Link: http://lkml.kernel.org/r/20171013173214.27300-4-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:14 +0000 (17:36 -0800)]
x86/mm: set fields in deferred pages
Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),
flags and other fields in "struct page"es are never changed prior to
first initializing struct pages by going through __init_single_page().
With deferred struct page feature enabled, however, we set fields in
register_page_bootmem_info that are subsequently clobbered right after
in free_all_bootmem:
mem_init() {
register_page_bootmem_info();
free_all_bootmem();
...
}
When register_page_bootmem_info() is called only non-deferred struct
pages are initialized. But, this function goes through some reserved
pages which might be part of the deferred, and thus are not yet
initialized.
mem_init
register_page_bootmem_info
register_page_bootmem_info_node
get_page_bootmem
.. setting fields here ..
such as: page->freelist = (void *)type;
free_all_bootmem()
free_low_memory_core_early()
for_each_reserved_mem_region()
reserve_bootmem_region()
init_reserved_page() <- Only if this is deferred reserved page
__init_single_pfn()
__init_single_page()
memset(0) <-- Loose the set fields here
We end up with issue where, currently we do not observe problem as
memory is explicitly zeroed. But, if flag asserts are changed we can
start hitting issues.
Also, because in this patch series we will stop zeroing struct page
memory during allocation, we must make sure that struct pages are
properly initialized prior to using them.
The deferred-reserved pages are initialized in free_all_bootmem().
Therefore, the fix is to switch the above calls.
Link: http://lkml.kernel.org/r/20171013173214.27300-3-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pavel Tatashin [Thu, 16 Nov 2017 01:36:09 +0000 (17:36 -0800)]
mm: deferred_init_memmap improvements
Patch series "complete deferred page initialization", v12.
SMP machines can benefit from the DEFERRED_STRUCT_PAGE_INIT config
option, which defers initializing struct pages until all cpus have been
started so it can be done in parallel.
However, this feature is sub-optimal, because the deferred page
initialization code expects that the struct pages have already been
zeroed, and the zeroing is done early in boot with a single thread only.
Also, we access that memory and set flags before struct pages are
initialized. All of this is fixed in this patchset.
In this work we do the following:
- Never read access struct page until it was initialized
- Never set any fields in struct pages before they are initialized
- Zero struct page at the beginning of struct page initialization
==========================================================================
Performance improvements on x86 machine with 8 nodes:
Intel(R) Xeon(R) CPU E7-8895 v3 @ 2.60GHz and 1T of memory:
TIME SPEED UP
base no deferred: 95.796233s
fix no deferred: 79.978956s 19.77%
base deferred: 77.254713s
fix deferred: 55.050509s 40.34%
==========================================================================
SPARC M6 3600 MHz with 15T of memory
TIME SPEED UP
base no deferred: 358.335727s
fix no deferred: 302.320936s 18.52%
base deferred: 237.534603s
fix deferred: 182.103003s 30.44%
==========================================================================
Raw dmesg output with timestamps:
x86 base no deferred: https://hastebin.com/ofunepurit.scala
x86 base deferred: https://hastebin.com/ifazegeyas.scala
x86 fix no deferred: https://hastebin.com/pegocohevo.scala
x86 fix deferred: https://hastebin.com/ofupevikuk.scala
sparc base no deferred: https://hastebin.com/ibobeteken.go
sparc base deferred: https://hastebin.com/fariqimiyu.go
sparc fix no deferred: https://hastebin.com/muhegoheyi.go
sparc fix deferred: https://hastebin.com/xadinobutu.go
This patch (of 11):
deferred_init_memmap() is called when struct pages are initialized later
in boot by slave CPUs. This patch simplifies and optimizes this
function, and also fixes a couple issues (described below).
The main change is that now we are iterating through free memblock areas
instead of all configured memory. Thus, we do not have to check if the
struct page has already been initialized.
=====
In deferred_init_memmap() where all deferred struct pages are
initialized we have a check like this:
if (page->flags) {
VM_BUG_ON(page_zone(page) != zone);
goto free_range;
}
This way we are checking if the current deferred page has already been
initialized. It works, because memory for struct pages has been zeroed,
and the only way flags are not zero if it went through
__init_single_page() before. But, once we change the current behavior
and won't zero the memory in memblock allocator, we cannot trust
anything inside "struct page"es until they are initialized. This patch
fixes this.
The deferred_init_memmap() is re-written to loop through only free
memory ranges provided by memblock.
Note, this first issue is relevant only when the following change is
merged:
=====
This patch fixes another existing issue on systems that have holes in
zones i.e CONFIG_HOLES_IN_ZONE is defined.
In for_each_mem_pfn_range() we have code like this:
if (!pfn_valid_within(pfn)
goto free_range;
Note: 'page' is not set to NULL and is not incremented but 'pfn'
advances. Thus means if deferred struct pages are enabled on systems
with these kind of holes, linux would get memory corruptions. I have
fixed this issue by defining a new macro that performs all the necessary
operations when we free the current set of pages.
[pasha.tatashin@oracle.com: buddy page accessed before initialized]
Link: http://lkml.kernel.org/r/20171102170221.7401-2-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20171013173214.27300-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Changbin Du [Thu, 16 Nov 2017 01:36:06 +0000 (17:36 -0800)]
mm/swap_state.c: declare a few variables as __read_mostly
These global variables are only set during initialization or rarely
change, so declare them as __read_mostly.
Link: http://lkml.kernel.org/r/1507802349-5554-1-git-send-email-changbin.du@intel.com
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Levin, Alexander (Sasha Levin) [Thu, 16 Nov 2017 01:36:02 +0000 (17:36 -0800)]
kmemcheck: rip it out
Fix up makefiles, remove references, and git rm kmemcheck.
Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Levin, Alexander (Sasha Levin) [Thu, 16 Nov 2017 01:35:58 +0000 (17:35 -0800)]
kmemcheck: remove whats left of NOTRACK flags
Now that kmemcheck is gone, we don't need the NOTRACK flags.
Link: http://lkml.kernel.org/r/20171007030159.22241-5-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Levin, Alexander (Sasha Levin) [Thu, 16 Nov 2017 01:35:54 +0000 (17:35 -0800)]
kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK
Convert all allocations that used a NOTRACK flag to stop using it.
Link: http://lkml.kernel.org/r/20171007030159.22241-3-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Levin, Alexander (Sasha Levin) [Thu, 16 Nov 2017 01:35:51 +0000 (17:35 -0800)]
kmemcheck: remove annotations
Patch series "kmemcheck: kill kmemcheck", v2.
As discussed at LSF/MM, kill kmemcheck.
KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow). KASan is already upstream.
We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).
The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.
Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.
This patch (of 4):
Remove kmemcheck annotations, and calls to kmemcheck from the kernel.
[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Colin Ian King [Thu, 16 Nov 2017 01:35:47 +0000 (17:35 -0800)]
mm/rmap.c: remove redundant variable cend
Variable cend is set but never read, hence it is redundant and can be
removed.
Cleans up clang build warning: Value stored to 'cend' is never read
Link: http://lkml.kernel.org/r/20171011174942.1372-1-colin.king@canonical.com
Fixes: 369ea8242c0f ("mm/rmap: update to new mmu_notifier semantic v2")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shakeel Butt [Thu, 16 Nov 2017 01:35:44 +0000 (17:35 -0800)]
fs, mm: account filp cache to kmemcg
The allocations from filp cache can be directly triggered by userspace
applications. A buggy application can consume a significant amount of
unaccounted system memory. Though we have not noticed such buggy
applications in our production but upon close inspection, we found that
a lot of machines spend very significant amount of memory on these
caches.
One way to limit allocations from filp cache is to set system level
limit of maximum number of open files. However this limit is shared
between different users on the system and one user can hog this
resource. To cater that, we can charge filp to kmemcg and set the
maximum limit very high and let the memory limit of each user limit the
number of files they can open and indirectly limiting their allocations
from filp cache.
One side effect of this change is that it will allow _sysctl() to return
ENOMEM and the man page of _sysctl() does not specify that. However the
man page also discourages to use _sysctl() at all.
Link: http://lkml.kernel.org/r/20171011190359.34926-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Thu, 16 Nov 2017 01:35:40 +0000 (17:35 -0800)]
mm: consolidate page table accounting
Currently, we account page tables separately for each page table level,
but that's redundant -- we only make use of total memory allocated to
page tables for oom_badness calculation. We also provide the
information to userspace, but it has dubious value there too.
This patch switches page table accounting to single counter.
mm->pgtables_bytes is now used to account all page table levels. We use
bytes, because page table size for different levels of page table tree
may be different.
The change has user-visible effect: we don't have VmPMD and VmPUD
reported in /proc/[pid]/status. Not sure if anybody uses them. (As
alternative, we can always report 0 kB for them.)
OOM-killer report is also slightly changed: we now report pgtables_bytes
instead of nr_ptes, nr_pmd, nr_puds.
Apart from reducing number of counters per-mm, the benefit is that we
now calculate oom_badness() more correctly for machines which have
different size of page tables depending on level or where page tables
are less than a page in size.
The only downside can be debuggability because we do not know which page
table level could leak. But I do not remember many bugs that would be
caught by separate counters so I wouldn't lose sleep over this.
[akpm@linux-foundation.org: fix mm/huge_memory.c]
Link: http://lkml.kernel.org/r/20171006100651.44742-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
[kirill.shutemov@linux.intel.com: fix build]
Link: http://lkml.kernel.org/r/20171016150113.ikfxy3e7zzfvsr4w@black.fi.intel.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Thu, 16 Nov 2017 01:35:37 +0000 (17:35 -0800)]
mm: introduce wrappers to access mm->nr_ptes
Let's add wrappers for ->nr_ptes with the same interface as for nr_pmd
and nr_pud.
The patch also makes nr_ptes accounting dependent onto CONFIG_MMU. Page
table accounting doesn't make sense if you don't have page tables.
It's preparation for consolidation of page-table counters in mm_struct.
Link: http://lkml.kernel.org/r/20171006100651.44742-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov [Thu, 16 Nov 2017 01:35:33 +0000 (17:35 -0800)]
mm: account pud page tables
On a machine with 5-level paging support a process can allocate
significant amount of memory and stay unnoticed by oom-killer and memory
cgroup. The trick is to allocate a lot of PUD page tables. We don't
account PUD page tables, only PMD and PTE.
We already addressed the same issue for PMD page tables, see commit
dc6c9a35b66b ("mm: account pmd page tables to the process").
Introduction of 5-level paging brings the same issue for PUD page
tables.
The patch expands accounting to PUD level.
[kirill.shutemov@linux.intel.com: s/pmd_t/pud_t/]
Link: http://lkml.kernel.org/r/20171004074305.x35eh5u7ybbt5kar@black.fi.intel.com
[heiko.carstens@de.ibm.com: s390/mm: fix pud table accounting]
Link: http://lkml.kernel.org/r/20171103090551.18231-1-heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20171002080427.3320-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Konstantin Khlebnikov [Thu, 16 Nov 2017 01:35:30 +0000 (17:35 -0800)]
kmemleak: change /sys/kernel/debug/kmemleak permissions from 0444 to 0644
Kmemleak can be tweaked at runtime by writing commands into debugfs
file. Root can use it anyway, but without the write-bit this interface
isn't obvious.
Link: http://lkml.kernel.org/r/150728996582.744328.11541332857988399411.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:26 +0000 (17:35 -0800)]
cifs: use find_get_pages_range_tag()
wdata_alloc_and_fillpages() needlessly iterates calls to
find_get_pages_tag(). Also it wants only pages from given range. Make
it use find_get_pages_range_tag().
Link: http://lkml.kernel.org/r/20171009151359.31984-17-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Suggested-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:23 +0000 (17:35 -0800)]
afs: use find_get_pages_range_tag()
Use find_get_pages_range_tag() in afs_writepages_region() as we are
interested only in pages from given range. Remove unnecessary code
after this conversion.
Link: http://lkml.kernel.org/r/20171009151359.31984-16-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:19 +0000 (17:35 -0800)]
mm: remove nr_pages argument from pagevec_lookup_{,range}_tag()
All users of pagevec_lookup() and pagevec_lookup_range() now pass
PAGEVEC_SIZE as a desired number of pages. Just drop the argument.
Link: http://lkml.kernel.org/r/20171009151359.31984-15-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:16 +0000 (17:35 -0800)]
ceph: use pagevec_lookup_range_nr_tag()
Use new function for looking up pages since nr_pages argument from
pagevec_lookup_range_tag() is going away.
Link: http://lkml.kernel.org/r/20171009151359.31984-14-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:12 +0000 (17:35 -0800)]
mm: add variant of pagevec_lookup_range_tag() taking number of pages
Currently pagevec_lookup_range_tag() takes number of pages to look up
but most users don't need this. Create a new function
pagevec_lookup_range_nr_tag() that takes maximum number of pages to
lookup for Ceph which wants this functionality so that we can drop
nr_pages argument from pagevec_lookup_range_tag().
Link: http://lkml.kernel.org/r/20171009151359.31984-13-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:09 +0000 (17:35 -0800)]
mm: use pagevec_lookup_range_tag() in write_cache_pages()
Use pagevec_lookup_range_tag() in write_cache_pages() as it is
interested only in pages from given range. Remove unnecessary code
resulting from this.
Link: http://lkml.kernel.org/r/20171009151359.31984-12-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:05 +0000 (17:35 -0800)]
mm: use pagevec_lookup_range_tag() in __filemap_fdatawait_range()
Use pagevec_lookup_range_tag() in __filemap_fdatawait_range() as it is
interested only in pages from given range. Remove unnecessary code
resulting from this.
Link: http://lkml.kernel.org/r/20171009151359.31984-11-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:35:02 +0000 (17:35 -0800)]
nilfs2: use pagevec_lookup_range_tag()
We want only pages from given range in nilfs_lookup_dirty_data_buffers().
Use pagevec_lookup_range_tag() instead of pagevec_lookup_tag() and
remove unnecessary code.
Link: http://lkml.kernel.org/r/20171009151359.31984-10-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:58 +0000 (17:34 -0800)]
gfs2: use pagevec_lookup_range_tag()
We want only pages from given range in gfs2_write_cache_jdata(). Use
pagevec_lookup_range_tag() instead of pagevec_lookup_tag() and remove
unnecessary code.
Link: http://lkml.kernel.org/r/20171009151359.31984-9-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:55 +0000 (17:34 -0800)]
f2fs: use find_get_pages_tag() for looking up single page
__get_first_dirty_index() wants to lookup only the first dirty page
after given index. There's no point in using pagevec_lookup_tag() for
that. Just use find_get_pages_tag() directly.
Link: http://lkml.kernel.org/r/20171009151359.31984-8-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:51 +0000 (17:34 -0800)]
f2fs: simplify page iteration loops
In several places we want to iterate over all tagged pages in a mapping.
However the code was apparently copied from places that iterate only
over a limited range and thus it checks for index <= end, optimizes the
case where we are coming close to range end which is all pointless when
end == ULONG_MAX. So just remove this dead code.
[akpm@linux-foundation.org: fix warnings]
Link: http://lkml.kernel.org/r/20171009151359.31984-7-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:48 +0000 (17:34 -0800)]
f2fs: use pagevec_lookup_range_tag()
We want only pages from given range in f2fs_write_cache_pages(). Use
pagevec_lookup_range_tag() instead of pagevec_lookup_tag() and remove
unnecessary code.
Link: http://lkml.kernel.org/r/20171009151359.31984-6-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:44 +0000 (17:34 -0800)]
ext4: use pagevec_lookup_range_tag()
We want only pages from given range in ext4_writepages(). Use
pagevec_lookup_range_tag() instead of pagevec_lookup_tag() and remove
unnecessary code.
Link: http://lkml.kernel.org/r/20171009151359.31984-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:41 +0000 (17:34 -0800)]
ceph: use pagevec_lookup_range_tag()
We want only pages from given range in ceph_writepages_start(). Use
pagevec_lookup_range_tag() instead of pagevec_lookup_tag() and remove
unnecessary code.
Link: http://lkml.kernel.org/r/20171009151359.31984-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:37 +0000 (17:34 -0800)]
btrfs: use pagevec_lookup_range_tag()
We want only pages from given range in btree_write_cache_pages() and
extent_write_cache_pages(). Use pagevec_lookup_range_tag() instead of
pagevec_lookup_tag() and remove unnecessary code.
Link: http://lkml.kernel.org/r/20171009151359.31984-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Sterba <dsterba@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Thu, 16 Nov 2017 01:34:33 +0000 (17:34 -0800)]
mm: implement find_get_pages_range_tag()
Patch series "Ranged pagevec tagged lookup", v3.
In this series I provide a ranged variant of pagevec_lookup_tag() and
use it in places where it makes sense. This series removes some common
code and it also has a potential for speeding up some operations
similarly as for pagevec_lookup_range() (but for now I can think of only
artificial cases where this happens).
This patch (of 16):
Implement a variant of find_get_pages_tag() that stops iterating at
given index. Lots of users of this function (through pagevec_lookup())
actually want a range lookup and all of them are currently open-coding
this.
Also create corresponding pagevec_lookup_range_tag() function.
Link: http://lkml.kernel.org/r/20171009151359.31984-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steve French <sfrench@samba.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ayush Mittal [Thu, 16 Nov 2017 01:34:30 +0000 (17:34 -0800)]
mm/page_owner.c: reduce page_owner structure size
Maximum page order can be at max 10 which can be accomodated in short
data type(2 bytes). last_migrate_reason is defined as enum type whose
values can be accomodated in short data type (2 bytes).
Total structure size is currently 16 bytes but after changing structure
size it goes to 12 bytes.
Vlastimil said:
"Looks like it works, so why not.
Before:
[ 0.001000] allocated
50331648 bytes of page_ext
After:
[ 0.001000] allocated
41943040 bytes of page_ext"
Link: http://lkml.kernel.org/r/1507623917-37991-1-git-send-email-ayush.m@samsung.com
Signed-off-by: Ayush Mittal <ayush.m@samsung.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pintu Agarwal [Thu, 16 Nov 2017 01:34:26 +0000 (17:34 -0800)]
mm/cma.c: change pr_info to pr_err for cma_alloc fail log
It was observed that under cma_alloc fail log, pr_info was used instead
of pr_err. This will lead to problems if printk debug level is set to
below 7. In this case the cma_alloc failure log will not be captured in
the log and it will be difficult to debug.
Simply replace the pr_info with pr_err to capture failure log.
Link: http://lkml.kernel.org/r/1507650633-4430-1-git-send-email-pintu.ping@gmail.com
Signed-off-by: Pintu Agarwal <pintu.ping@gmail.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jaewon Kim <jaewon31.kim@samsung.com>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 16 Nov 2017 01:34:22 +0000 (17:34 -0800)]
mm, arch: remove empty_bad_page*
empty_bad_page() and empty_bad_pte_table() seem to be relics from old
days which is not used by any code for a long time. I have tried to
find when exactly but this is not really all that straightforward due to
many code movements - traces disappear around 2.4 times.
Anyway no code really references neither empty_bad_page nor
empty_bad_pte_table. We only allocate the storage which is not used by
anybody so remove them.
Link: http://lkml.kernel.org/r/20171004150045.30755-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Ralf Baechle <ralf@linus-mips.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David Howells <dhowells@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tim Chen [Thu, 16 Nov 2017 01:34:18 +0000 (17:34 -0800)]
mm/swap_slots.c: fix race conditions in swap_slots cache init
Memory allocations can happen before the swap_slots cache initialization
is completed during cpu bring up. If we are low on memory, we could
call get_swap_page() and access swap_slots_cache before it is fully
initialized.
Add a check in get_swap_page() for initialized swap_slots_cache to
prevent this condition. Similar check already exists in free_swap_slot.
Also annotate the checks to indicate the likely condition.
We also added a memory barrier to make sure that the locks
initialization are done before the assignment of cache->slots and
cache->slots_ret pointers. This ensures the assumption that it is safe
to acquire the slots cache locks and use the slots cache when the
corresponding cache->slots or cache->slots_ret pointers are non null.
[akpm@linux-foundation.org: tidy up comment]
[akpm@linux-foundation.org: fix spello in comment]
Link: http://lkml.kernel.org/r/65a9d0f133f63e66bba37b53b2fd0464b7cae771.1500677066.git.tim.c.chen@linux.intel.com
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Reported-by: Wenwei Tao <wenwei.tww@alibaba-inc.com>
Acked-by: Ying Huang <ying.huang@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Ryabinin [Thu, 16 Nov 2017 01:34:15 +0000 (17:34 -0800)]
mm: remove unused pgdat->inactive_ratio
Since commit
59dc76b0d4df ("mm: vmscan: reduce size of inactive file
list") 'pgdat->inactive_ratio' is not used, except for printing
"node_inactive_ratio: 0" in /proc/zoneinfo output.
Remove it.
Link: http://lkml.kernel.org/r/20171003152611.27483-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jérôme Glisse [Thu, 16 Nov 2017 01:34:11 +0000 (17:34 -0800)]
mm/mmu_notifier: avoid call to invalidate_range() in range_end()
This is an optimization patch that only affect mmu_notifier users which
rely on the invalidate_range() callback. This patch avoids calling that
callback twice in a row from inside __mmu_notifier_invalidate_range_end
Existing pattern (before this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_end()
mmu_notifier_invalidate_range()
New pattern (after this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_only_end()
We call the invalidate_range callback after clearing the page table
under the page table lock and we skip the call to invalidate_range
inside the __mmu_notifier_invalidate_range_end() function.
Idea from Andrea Arcangeli
Link: http://lkml.kernel.org/r/20171017031003.7481-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jérôme Glisse [Thu, 16 Nov 2017 01:34:07 +0000 (17:34 -0800)]
mm/mmu_notifier: avoid double notification when it is useless
This patch only affects users of mmu_notifier->invalidate_range callback
which are device drivers related to ATS/PASID, CAPI, IOMMUv2, SVM ...
and it is an optimization for those users. Everyone else is unaffected
by it.
When clearing a pte/pmd we are given a choice to notify the event under
the page table lock (notify version of *_clear_flush helpers do call the
mmu_notifier_invalidate_range). But that notification is not necessary
in all cases.
This patch removes almost all cases where it is useless to have a call
to mmu_notifier_invalidate_range before
mmu_notifier_invalidate_range_end. It also adds documentation in all
those cases explaining why.
Below is a more in depth analysis of why this is fine to do this:
For secondary TLB (non CPU TLB) like IOMMU TLB or device TLB (when
device use thing like ATS/PASID to get the IOMMU to walk the CPU page
table to access a process virtual address space). There is only 2 cases
when you need to notify those secondary TLB while holding page table
lock when clearing a pte/pmd:
A) page backing address is free before mmu_notifier_invalidate_range_end
B) a page table entry is updated to point to a new page (COW, write fault
on zero page, __replace_page(), ...)
Case A is obvious you do not want to take the risk for the device to write
to a page that might now be used by something completely different.
Case B is more subtle. For correctness it requires the following sequence
to happen:
- take page table lock
- clear page table entry and notify (pmd/pte_huge_clear_flush_notify())
- set page table entry to point to new page
If clearing the page table entry is not followed by a notify before setting
the new pte/pmd value then you can break memory model like C11 or C++11 for
the device.
Consider the following scenario (device use a feature similar to ATS/
PASID):
Two address addrA and addrB such that |addrA - addrB| >= PAGE_SIZE we
assume they are write protected for COW (other case of B apply too).
[Time N] -----------------------------------------------------------------
CPU-thread-0 {try to write to addrA}
CPU-thread-1 {try to write to addrB}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {read addrA and populate device TLB}
DEV-thread-2 {read addrB and populate device TLB}
[Time N+1] ---------------------------------------------------------------
CPU-thread-0 {COW_step0: {mmu_notifier_invalidate_range_start(addrA)}}
CPU-thread-1 {COW_step0: {mmu_notifier_invalidate_range_start(addrB)}}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+2] ---------------------------------------------------------------
CPU-thread-0 {COW_step1: {update page table point to new page for addrA}}
CPU-thread-1 {COW_step1: {update page table point to new page for addrB}}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+3] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {preempted}
CPU-thread-2 {write to addrA which is a write to new page}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+3] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {preempted}
CPU-thread-2 {}
CPU-thread-3 {write to addrB which is a write to new page}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+4] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {COW_step3: {mmu_notifier_invalidate_range_end(addrB)}}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+5] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {read addrA from old page}
DEV-thread-2 {read addrB from new page}
So here because at time N+2 the clear page table entry was not pair with a
notification to invalidate the secondary TLB, the device see the new value
for addrB before seing the new value for addrA. This break total memory
ordering for the device.
When changing a pte to write protect or to point to a new write protected
page with same content (KSM) it is ok to delay invalidate_range callback
to mmu_notifier_invalidate_range_end() outside the page table lock. This
is true even if the thread doing page table update is preempted right
after releasing page table lock before calling
mmu_notifier_invalidate_range_end
Thanks to Andrea for thinking of a problematic scenario for COW.
[jglisse@redhat.com: v2]
Link: http://lkml.kernel.org/r/20171017031003.7481-2-jglisse@redhat.com
Link: http://lkml.kernel.org/r/20170901173011.10745-1-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Thu, 16 Nov 2017 01:34:03 +0000 (17:34 -0800)]
zsmalloc: calling zs_map_object() from irq is a bug
Use BUG_ON(in_interrupt()) in zs_map_object(). This is not a new
BUG_ON(), it's always been there, but was recently changed to
VM_BUG_ON(). There are several problems there. First, we use use
per-CPU mappings both in zsmalloc and in zram, and interrupt may easily
corrupt those buffers. Second, and more importantly, we believe it's
possible to start leaking sensitive information. Consider the following
case:
-> process P
swap out
zram
per-cpu mapping CPU1
compress page A
-> IRQ
swap out
zram
per-cpu mapping CPU1
compress page B
write page from per-cpu mapping CPU1 to zsmalloc pool
iret
-> process P
write page from per-cpu mapping CPU1 to zsmalloc pool [*]
return
* so we store overwritten data that actually belongs to another
page (task) and potentially contains sensitive data. And when
process P will page fault it's going to read (swap in) that
other task's data.
Link: http://lkml.kernel.org/r/20170929045140.4055-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ralph Campbell [Thu, 16 Nov 2017 01:34:00 +0000 (17:34 -0800)]
mm/hmm: constify hmm_devmem_page_get_drvdata() parameter
Constify pointer parameter to avoid issue when use from code that only
has const struct page pointer to use in the first place.
Link: http://lkml.kernel.org/r/1506972774-10191-1-git-send-email-jglisse@redhat.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anshuman Khandual [Thu, 16 Nov 2017 01:33:56 +0000 (17:33 -0800)]
fs/hugetlbfs/inode.c: remove redundant -ENIVAL return from hugetlbfs_setattr()
There is no need to have a local return code set with -EINVAL when both
the conditions following it return error codes appropriately. Just
remove the redundant one.
Link: http://lkml.kernel.org/r/20170929145444.17611-1-khandual@linux.vnet.ibm.com
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Thu, 16 Nov 2017 01:33:53 +0000 (17:33 -0800)]
zram: remove zlib from the list of recommended algorithms
ZSTD tends to outperform deflate/inflate, thus we remove zlib from the
list of recommended algorithms and recommend zstd instead.
Link: http://lkml.kernel.org/r/20170912050005.3247-2-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatsky [Thu, 16 Nov 2017 01:33:49 +0000 (17:33 -0800)]
zram: add zstd to the supported algorithms list
Add ZSTD to the list of supported compression algorithms.
ZRAM fio perf test:
LZO DEFLATE ZSTD
#jobs1
WRITE: (2180MB/s) (77.2MB/s) (1429MB/s)
WRITE: (1617MB/s) (77.7MB/s) (1202MB/s)
READ: (426MB/s) (595MB/s) (1181MB/s)
READ: (422MB/s) (572MB/s) (1020MB/s)
READ: (318MB/s) (67.8MB/s) (563MB/s)
WRITE: (318MB/s) (67.9MB/s) (564MB/s)
READ: (336MB/s) (68.3MB/s) (583MB/s)
WRITE: (335MB/s) (68.2MB/s) (582MB/s)
#jobs2
WRITE: (3441MB/s) (152MB/s) (2141MB/s)
WRITE: (2507MB/s) (147MB/s) (1888MB/s)
READ: (801MB/s) (1146MB/s) (1890MB/s)
READ: (767MB/s) (1096MB/s) (2073MB/s)
READ: (621MB/s) (126MB/s) (1009MB/s)
WRITE: (621MB/s) (126MB/s) (1009MB/s)
READ: (656MB/s) (125MB/s) (1075MB/s)
WRITE: (657MB/s) (126MB/s) (1077MB/s)
#jobs3
WRITE: (4772MB/s) (225MB/s) (3394MB/s)
WRITE: (3905MB/s) (211MB/s) (2939MB/s)
READ: (1216MB/s) (1608MB/s) (3218MB/s)
READ: (1159MB/s) (1431MB/s) (2981MB/s)
READ: (906MB/s) (156MB/s) (1457MB/s)
WRITE: (907MB/s) (156MB/s) (1458MB/s)
READ: (953MB/s) (158MB/s) (1595MB/s)
WRITE: (952MB/s) (157MB/s) (1593MB/s)
#jobs4
WRITE: (6036MB/s) (265MB/s) (4469MB/s)
WRITE: (5059MB/s) (263MB/s) (3951MB/s)
READ: (1618MB/s) (2066MB/s) (4276MB/s)
READ: (1573MB/s) (1942MB/s) (3830MB/s)
READ: (1202MB/s) (227MB/s) (1971MB/s)
WRITE: (1200MB/s) (227MB/s) (1968MB/s)
READ: (1265MB/s) (226MB/s) (2116MB/s)
WRITE: (1264MB/s) (226MB/s) (2114MB/s)
#jobs5
WRITE: (5339MB/s) (233MB/s) (3781MB/s)
WRITE: (4298MB/s) (234MB/s) (3276MB/s)
READ: (1626MB/s) (2048MB/s) (4081MB/s)
READ: (1567MB/s) (1929MB/s) (3758MB/s)
READ: (1174MB/s) (205MB/s) (1747MB/s)
WRITE: (1173MB/s) (204MB/s) (1746MB/s)
READ: (1214MB/s) (208MB/s) (1890MB/s)
WRITE: (1215MB/s) (208MB/s) (1892MB/s)
#jobs6
WRITE: (5666MB/s) (270MB/s) (4338MB/s)
WRITE: (4828MB/s) (267MB/s) (3772MB/s)
READ: (1803MB/s) (2058MB/s) (4946MB/s)
READ: (1805MB/s) (2156MB/s) (4711MB/s)
READ: (1334MB/s) (235MB/s) (2135MB/s)
WRITE: (1335MB/s) (235MB/s) (2137MB/s)
READ: (1364MB/s) (236MB/s) (2268MB/s)
WRITE: (1365MB/s) (237MB/s) (2270MB/s)
#jobs7
WRITE: (5474MB/s) (270MB/s) (4300MB/s)
WRITE: (4666MB/s) (266MB/s) (3817MB/s)
READ: (2022MB/s) (2319MB/s) (5472MB/s)
READ: (1924MB/s) (2260MB/s) (5031MB/s)
READ: (1369MB/s) (242MB/s) (2153MB/s)
WRITE: (1370MB/s) (242MB/s) (2155MB/s)
READ: (1499MB/s) (246MB/s) (2310MB/s)
WRITE: (1497MB/s) (246MB/s) (2307MB/s)
#jobs8
WRITE: (5558MB/s) (273MB/s) (4439MB/s)
WRITE: (4763MB/s) (271MB/s) (3918MB/s)
READ: (2201MB/s) (2599MB/s) (6062MB/s)
READ: (2105MB/s) (2463MB/s) (5413MB/s)
READ: (1490MB/s) (252MB/s) (2238MB/s)
WRITE: (1488MB/s) (252MB/s) (2236MB/s)
READ: (1566MB/s) (254MB/s) (2434MB/s)
WRITE: (1568MB/s) (254MB/s) (2437MB/s)
#jobs9
WRITE: (5120MB/s) (264MB/s) (4035MB/s)
WRITE: (4531MB/s) (267MB/s) (3740MB/s)
READ: (1940MB/s) (2258MB/s) (4986MB/s)
READ: (2024MB/s) (2387MB/s) (4871MB/s)
READ: (1343MB/s) (246MB/s) (2038MB/s)
WRITE: (1342MB/s) (246MB/s) (2037MB/s)
READ: (1553MB/s) (238MB/s) (2243MB/s)
WRITE: (1552MB/s) (238MB/s) (2242MB/s)
#jobs10
WRITE: (5345MB/s) (271MB/s) (3988MB/s)
WRITE: (4750MB/s) (254MB/s) (3668MB/s)
READ: (1876MB/s) (2363MB/s) (5150MB/s)
READ: (1990MB/s) (2256MB/s) (5080MB/s)
READ: (1355MB/s) (250MB/s) (2019MB/s)
WRITE: (1356MB/s) (251MB/s) (2020MB/s)
READ: (1490MB/s) (252MB/s) (2202MB/s)
WRITE: (1488MB/s) (252MB/s) (2199MB/s)
jobs1 perfstat
instructions 52,065,555,710 ( 0.79) 855,731,114,587 ( 2.64) 54,280,709,944 ( 1.40)
branches 14,020,427,116 ( 725.847) 101,733,449,582 (1074.521) 11,170,591,067 ( 992.869)
branch-misses 22,626,174 ( 0.16%) 274,197,885 ( 0.27%) 25,915,805 ( 0.23%)
jobs2 perfstat
instructions 103,633,110,402 ( 0.75) 1,710,822,100,914 ( 2.59) 107,879,874,104 ( 1.28)
branches 27,931,237,282 ( 679.203) 203,298,267,479 (1037.326) 22,185,350,842 ( 884.427)
branch-misses 46,103,811 ( 0.17%) 533,747,204 ( 0.26%) 49,682,483 ( 0.22%)
jobs3 perfstat
instructions 154,857,283,657 ( 0.76) 2,565,748,974,197 ( 2.57) 161,515,435,813 ( 1.31)
branches 41,759,490,355 ( 670.529) 304,905,605,277 ( 978.765) 33,215,805,907 ( 888.003)
branch-misses 74,263,293 ( 0.18%) 759,746,240 ( 0.25%) 76,841,196 ( 0.23%)
jobs4 perfstat
instructions 206,215,849,076 ( 0.75) 3,420,169,460,897 ( 2.60) 215,003,061,664 ( 1.31)
branches 55,632,141,739 ( 666.501) 406,394,977,433 ( 927.241) 44,214,322,251 ( 883.532)
branch-misses 102,287,788 ( 0.18%) 1,098,617,314 ( 0.27%) 103,891,040 ( 0.23%)
jobs5 perfstat
instructions 258,711,315,588 ( 0.67) 4,275,657,533,244 ( 2.23) 269,332,235,685 ( 1.08)
branches 69,802,821,166 ( 588.823) 507,996,211,252 ( 797.036) 55,450,846,129 ( 735.095)
branch-misses 129,217,214 ( 0.19%) 1,243,284,991 ( 0.24%) 173,512,278 ( 0.31%)
jobs6 perfstat
instructions 312,796,166,008 ( 0.61) 5,133,896,344,660 ( 2.02) 323,658,769,588 ( 1.04)
branches 84,372,488,583 ( 520.541) 610,310,494,402 ( 697.642) 66,683,292,992 ( 693.939)
branch-misses 159,438,978 ( 0.19%) 1,396,368,563 ( 0.23%) 174,406,934 ( 0.26%)
jobs7 perfstat
instructions 363,211,372,930 ( 0.56) 5,988,205,600,879 ( 1.75) 377,824,674,156 ( 0.93)
branches 98,057,013,765 ( 463.117) 711,841,255,974 ( 598.762) 77,879,009,954 ( 600.443)
branch-misses 199,513,153 ( 0.20%) 1,507,651,077 ( 0.21%) 248,203,369 ( 0.32%)
jobs8 perfstat
instructions 413,960,354,615 ( 0.52) 6,842,918,558,378 ( 1.45) 431,938,486,581 ( 0.83)
branches 111,812,574,884 ( 414.224) 813,299,084,518 ( 491.173) 89,062,699,827 ( 517.795)
branch-misses 233,584,845 ( 0.21%) 1,531,593,921 ( 0.19%) 286,818,489 ( 0.32%)
jobs9 perfstat
instructions 465,976,220,300 ( 0.53) 7,698,467,237,372 ( 1.47) 486,352,600,321 ( 0.84)
branches 125,931,456,162 ( 424.063) 915,207,005,715 ( 498.192) 100,370,404,090 ( 517.439)
branch-misses 256,992,445 ( 0.20%) 1,782,809,816 ( 0.19%) 345,239,380 ( 0.34%)
jobs10 perfstat
instructions 517,406,372,715 ( 0.53) 8,553,527,312,900 ( 1.48) 540,732,653,094 ( 0.84)
branches 139,839,780,676 ( 427.732) 1,016,737,699,389 ( 503.172) 111,696,557,638 ( 516.750)
branch-misses 259,595,561 ( 0.19%) 1,952,570,279 ( 0.19%) 357,818,661 ( 0.32%)
seconds elapsed 20.
630411534 96.
084546565 12.
743373571
seconds elapsed 22.
292627625 100.
984155001 14.
407413560
seconds elapsed 22.
396016966 110.
344880848 14.
032201392
seconds elapsed 22.
517330949 113.
351459170 14.
243074935
seconds elapsed 28.
548305104 156.
515193765 19.
159286861
seconds elapsed 30.
453538116 164.
559937678 19.
362492717
seconds elapsed 33.
467108086 188.
486827481 21.
492612173
seconds elapsed 35.
617727591 209.
602677783 23.
256422492
seconds elapsed 42.
584239509 243.
959902566 28.
458540338
seconds elapsed 47.
683632526 269.
635248851 31.
542404137
Over all, ZSTD has slower WRITE, but much faster READ (perhaps
a static compression buffer used during the test helped ZSTD a
lot), which results in faster test results.
Memory consumption (zram mm_stat file):
zram LZO mm_stat
mm_stat (jobs1):
2147483648 23068672 33558528 0
33558528 0 0
mm_stat (jobs2):
2147483648 23068672 33558528 0
33558528 0 0
mm_stat (jobs3):
2147483648 23068672 33558528 0
33562624 0 0
mm_stat (jobs4):
2147483648 23068672 33558528 0
33558528 0 0
mm_stat (jobs5):
2147483648 23068672 33558528 0
33558528 0 0
mm_stat (jobs6):
2147483648 23068672 33558528 0
33562624 0 0
mm_stat (jobs7):
2147483648 23068672 33558528 0
33566720 0 0
mm_stat (jobs8):
2147483648 23068672 33558528 0
33558528 0 0
mm_stat (jobs9):
2147483648 23068672 33558528 0
33558528 0 0
mm_stat (jobs10):
2147483648 23068672 33558528 0
33562624 0 0
zram DEFLATE mm_stat
mm_stat (jobs1):
2147483648 16252928 25178112 0
25178112 0 0
mm_stat (jobs2):
2147483648 16252928 25178112 0
25178112 0 0
mm_stat (jobs3):
2147483648 16252928 25178112 0
25178112 0 0
mm_stat (jobs4):
2147483648 16252928 25178112 0
25178112 0 0
mm_stat (jobs5):
2147483648 16252928 25178112 0
25178112 0 0
mm_stat (jobs6):
2147483648 16252928 25178112 0
25178112 0 0
mm_stat (jobs7):
2147483648 16252928 25178112 0
25190400 0 0
mm_stat (jobs8):
2147483648 16252928 25178112 0
25190400 0 0
mm_stat (jobs9):
2147483648 16252928 25178112 0
25178112 0 0
mm_stat (jobs10):
2147483648 16252928 25178112 0
25178112 0 0
zram ZSTD mm_stat
mm_stat (jobs1):
2147483648 11010048 16781312 0
16781312 0 0
mm_stat (jobs2):
2147483648 11010048 16781312 0
16781312 0 0
mm_stat (jobs3):
2147483648 11010048 16781312 0
16785408 0 0
mm_stat (jobs4):
2147483648 11010048 16781312 0
16781312 0 0
mm_stat (jobs5):
2147483648 11010048 16781312 0
16781312 0 0
mm_stat (jobs6):
2147483648 11010048 16781312 0
16781312 0 0
mm_stat (jobs7):
2147483648 11010048 16781312 0
16781312 0 0
mm_stat (jobs8):
2147483648 11010048 16781312 0
16781312 0 0
mm_stat (jobs9):
2147483648 11010048 16781312 0
16785408 0 0
mm_stat (jobs10):
2147483648 11010048 16781312 0
16781312 0 0
==================================================================================
Official benchmarks [1]:
Compressor name Ratio Compression Decompress.
zstd 1.1.3 -1 2.877 430 MB/s 1110 MB/s
zlib 1.2.8 -1 2.743 110 MB/s 400 MB/s
brotli 0.5.2 -0 2.708 400 MB/s 430 MB/s
quicklz 1.5.0 -1 2.238 550 MB/s 710 MB/s
lzo1x 2.09 -1 2.108 650 MB/s 830 MB/s
lz4 1.7.5 2.101 720 MB/s 3600 MB/s
snappy 1.1.3 2.091 500 MB/s 1650 MB/s
lzf 3.6 -1 2.077 400 MB/s 860 MB/s
Minchan said:
: I did test with my sample data and compared zstd with deflate. zstd's
: compress ratio is lower a little bit but compression speed is much faster
: 3 times more and decompress speed is too 2 times more. With different
: data, it is different but overall, zstd would be better for speed at the
: cost of a little lower compress ratio(about 5%) so I believe it's worth to
: replace deflate.
[1] https://github.com/facebook/zstd
Link: http://lkml.kernel.org/r/20170912050005.3247-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Tested-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yafang Shao [Thu, 16 Nov 2017 01:33:45 +0000 (17:33 -0800)]
mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical
The vm direct limit setting must be set greater than vm background limit
setting. Otherwise print a warning to help the operator to figure out
that the vm dirtiness settings is in illogical state.
Link: http://lkml.kernel.org/r/1506592464-30962-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Gioh Kim [Thu, 16 Nov 2017 01:33:42 +0000 (17:33 -0800)]
mm/memblock.c: make the index explicit argument of for_each_memblock_type
for_each_memblock_type macro function relies on idx variable defined in
the caller context. Silent macro arguments are almost always wrong
thing to do. They make code harder to read and easier to get wrong.
Let's use an explicit iterator parameter for for_each_memblock_type and
make the code more obious. This patch is a mere cleanup and it
shouldn't introduce any functional change.
Link: http://lkml.kernel.org/r/20170913133029.28911-1-gi-oh.kim@profitbricks.com
Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 16 Nov 2017 01:33:38 +0000 (17:33 -0800)]
mm, memory_hotplug: remove timeout from __offline_memory
We have a hardcoded 120s timeout after which the memory offline fails
basically since the hot remove has been introduced. This is essentially
a policy implemented in the kernel. Moreover there is no way to adjust
the timeout and so we are sometimes facing memory offline failures if
the system is under a heavy memory pressure or very intensive CPU
workload on large machines.
It is not very clear what purpose the timeout actually serves. The
offline operation is interruptible by a signal so if userspace wants
some timeout based termination this can be done trivially by sending a
signal.
If there is a strong usecase to do this from the kernel then we should
do it properly and have a it tunable from the userspace with the timeout
disabled by default along with the explanation who uses it and for what
purporse.
Link: http://lkml.kernel.org/r/20170918070834.13083-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 16 Nov 2017 01:33:34 +0000 (17:33 -0800)]
mm, memory_hotplug: do not fail offlining too early
Patch series "mm, memory_hotplug: redefine memory offline retry logic", v2.
While testing memory hotplug on a large 4TB machine we have noticed that
memory offlining is just too eager to fail. The primary reason is that
the retry logic is just too easy to give up. We have 4 ways out of the
offline
- we have a permanent failure (isolation or memory notifiers fail,
or hugetlb pages cannot be dropped)
- userspace sends a signal
- a hardcoded 120s timeout expires
- page migration fails 5 times
This is way too convoluted and it doesn't scale very well. We have seen
both temporary migration failures as well as 120s being triggered.
After removing those restrictions we were able to pass stress testing
during memory hot remove without any other negative side effects
observed. Therefore I suggest dropping both hard coded policies. I
couldn't have found any specific reason for them in the changelog. I
neither didn't get any response [1] from Kamezawa. If we need some
upper bound - e.g. timeout based - then we should have a proper and
user defined policy for that. In any case there should be a clear use
case when introducing it.
This patch (of 2):
Memory offlining can fail too eagerly under heavy memory pressure.
page:
ffffea22a646bd00 count:255 mapcount:252 mapping:
ffff88ff926c9f38 index:0x3
flags: 0x9855fe40010048(uptodate|active|mappedtodisk)
page dumped because: isolation failed
page->mem_cgroup:
ffff8801cd662000
memory offlining [mem 0x18b580000000-0x18b5ffffffff] failed
Isolation has failed here because the page is not on LRU. Most probably
because it was on the pcp LRU cache or it has been removed from the LRU
already but it hasn't been freed yet. In both cases the page doesn't
look non-migrable so retrying more makes sense.
__offline_pages seems rather cluttered when it comes to the retry logic.
We have 5 retries at maximum and a timeout. We could argue whether the
timeout makes sense but failing just because of a race when somebody
isoltes a page from LRU or puts it on a pcp LRU lists is just wrong. It
only takes it to race with a process which unmaps some pages and remove
them from the LRU list and we can fail the whole offline because of
something that is a temporary condition and actually not harmful for the
offline.
Please note that unmovable pages should be already excluded during
start_isolate_page_range. We could argue that has_unmovable_pages is
racy and MIGRATE_MOVABLE check doesn't provide any hard guarantee either
but kernel zones (aka < ZONE_MOVABLE) will very likely detect unmovable
pages in most cases and movable zone shouldn't contain unmovable pages
at all. Some of those pages might be pinned but not for ever because
that would be a bug on its own. In any case the context is still
interruptible and so the userspace can easily bail out when the
operation takes too long. This is certainly better behavior than a
hardcoded retry loop which is racy.
Fix this by removing the max retry count and only rely on the timeout
resp. interruption by a signal from the userspace. Also retry rather
than fail when check_pages_isolated sees some !free pages because those
could be a result of the race as well.
Link: http://lkml.kernel.org/r/20170918070834.13083-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / openwrt / staging / blogic.git / log