From 342332e6a925e9ed015e5465062c38d2b86ec8f9 Mon Sep 17 00:00:00 2001 From: Taku Izumi Date: Tue, 15 Mar 2016 14:55:22 -0700 Subject: [PATCH] mm/page_alloc.c: introduce kernelcore=mirror option This patch extends existing "kernelcore" option and introduces kernelcore=mirror option. By specifying "mirror" instead of specifying the amount of memory, non-mirrored (non-reliable) region will be arranged into ZONE_MOVABLE. [akpm@linux-foundation.org: fix build with CONFIG_HAVE_MEMBLOCK_NODE_MAP=n] Signed-off-by: Taku Izumi Tested-by: Sudeep Holla Cc: Tony Luck Cc: Xishi Qiu Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Dave Hansen Cc: Matt Fleming Cc: Arnd Bergmann Cc: Steve Capper Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 12 ++- mm/page_alloc.c | 114 ++++++++++++++++++++++++++-- 2 files changed, 119 insertions(+), 7 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8ae47a7b4923..208ae7287659 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1750,7 +1750,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. keepinitrd [HW,ARM] - kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter + kernelcore= [KNL,X86,IA-64,PPC] + Format: nn[KMGTPE] | "mirror" + This parameter specifies the amount of memory usable by the kernel for non-movable allocations. The requested amount is spread evenly throughout all nodes in the system. The @@ -1766,6 +1768,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. use the HighMem zone if it exists, and the Normal zone if it does not. + Instead of specifying the amount of memory (nn[KMGTPE]), + you can specify "mirror" option. In case "mirror" + option is specified, mirrored (reliable) memory is used + for non-movable allocations and remaining memory is used + for Movable pages. nn[KMGTPE] and "mirror" are exclusive, + so you can NOT specify nn[KMGTPE] and "mirror" at the same + time. + kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. Format: [,poll interval] The controller # is the number of the ehci usb debug diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0d20a19151a4..b8160b9d5e72 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -247,6 +247,7 @@ static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES]; static unsigned long __initdata required_kernelcore; static unsigned long __initdata required_movablecore; static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES]; +static bool mirrored_kernelcore; /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */ int movable_zone; @@ -4491,6 +4492,9 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, pg_data_t *pgdat = NODE_DATA(nid); unsigned long pfn; unsigned long nr_initialised = 0; +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + struct memblock_region *r = NULL, *tmp; +#endif if (highest_memmap_pfn < end_pfn - 1) highest_memmap_pfn = end_pfn - 1; @@ -4516,6 +4520,40 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised)) break; + +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + /* + * if not mirrored_kernelcore and ZONE_MOVABLE exists, + * range from zone_movable_pfn[nid] to end of each node + * should be ZONE_MOVABLE not ZONE_NORMAL. skip it. + */ + if (!mirrored_kernelcore && zone_movable_pfn[nid]) + if (zone == ZONE_NORMAL && + pfn >= zone_movable_pfn[nid]) + continue; + + /* + * check given memblock attribute by firmware which + * can affect kernel memory layout. + * if zone==ZONE_MOVABLE but memory is mirrored, + * it's an overlapped memmap init. skip it. + */ + if (mirrored_kernelcore && zone == ZONE_MOVABLE) { + if (!r || + pfn >= memblock_region_memory_end_pfn(r)) { + for_each_memblock(memory, tmp) + if (pfn < memblock_region_memory_end_pfn(tmp)) + break; + r = tmp; + } + if (pfn >= memblock_region_memory_base_pfn(r) && + memblock_is_mirror(r)) { + /* already initialized as NORMAL */ + pfn = memblock_region_memory_end_pfn(r); + continue; + } + } +#endif } /* @@ -4934,11 +4972,6 @@ static void __meminit adjust_zone_range_for_zone_movable(int nid, *zone_end_pfn = min(node_end_pfn, arch_zone_highest_possible_pfn[movable_zone]); - /* Adjust for ZONE_MOVABLE starting within this range */ - } else if (*zone_start_pfn < zone_movable_pfn[nid] && - *zone_end_pfn > zone_movable_pfn[nid]) { - *zone_end_pfn = zone_movable_pfn[nid]; - /* Check if this whole range is within ZONE_MOVABLE */ } else if (*zone_start_pfn >= zone_movable_pfn[nid]) *zone_start_pfn = *zone_end_pfn; @@ -5023,6 +5056,7 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid, unsigned long zone_low = arch_zone_lowest_possible_pfn[zone_type]; unsigned long zone_high = arch_zone_highest_possible_pfn[zone_type]; unsigned long zone_start_pfn, zone_end_pfn; + unsigned long nr_absent; /* When hotadd a new node from cpu_up(), the node should be empty */ if (!node_start_pfn && !node_end_pfn) @@ -5034,7 +5068,39 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid, adjust_zone_range_for_zone_movable(nid, zone_type, node_start_pfn, node_end_pfn, &zone_start_pfn, &zone_end_pfn); - return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); + nr_absent = __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn); + + /* + * ZONE_MOVABLE handling. + * Treat pages to be ZONE_MOVABLE in ZONE_NORMAL as absent pages + * and vice versa. + */ + if (zone_movable_pfn[nid]) { + if (mirrored_kernelcore) { + unsigned long start_pfn, end_pfn; + struct memblock_region *r; + + for_each_memblock(memory, r) { + start_pfn = clamp(memblock_region_memory_base_pfn(r), + zone_start_pfn, zone_end_pfn); + end_pfn = clamp(memblock_region_memory_end_pfn(r), + zone_start_pfn, zone_end_pfn); + + if (zone_type == ZONE_MOVABLE && + memblock_is_mirror(r)) + nr_absent += end_pfn - start_pfn; + + if (zone_type == ZONE_NORMAL && + !memblock_is_mirror(r)) + nr_absent += end_pfn - start_pfn; + } + } else { + if (zone_type == ZONE_NORMAL) + nr_absent += node_end_pfn - zone_movable_pfn[nid]; + } + } + + return nr_absent; } #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ @@ -5546,6 +5612,36 @@ static void __init find_zone_movable_pfns_for_nodes(void) goto out2; } + /* + * If kernelcore=mirror is specified, ignore movablecore option + */ + if (mirrored_kernelcore) { + bool mem_below_4gb_not_mirrored = false; + + for_each_memblock(memory, r) { + if (memblock_is_mirror(r)) + continue; + + nid = r->nid; + + usable_startpfn = memblock_region_memory_base_pfn(r); + + if (usable_startpfn < 0x100000) { + mem_below_4gb_not_mirrored = true; + continue; + } + + zone_movable_pfn[nid] = zone_movable_pfn[nid] ? + min(usable_startpfn, zone_movable_pfn[nid]) : + usable_startpfn; + } + + if (mem_below_4gb_not_mirrored) + pr_warn("This configuration results in unmirrored kernel memory."); + + goto out2; + } + /* * If movablecore=nn[KMG] was specified, calculate what size of * kernelcore that corresponds so that memory usable for @@ -5806,6 +5902,12 @@ static int __init cmdline_parse_core(char *p, unsigned long *core) */ static int __init cmdline_parse_kernelcore(char *p) { + /* parse kernelcore=mirror */ + if (parse_option_str(p, "mirror")) { + mirrored_kernelcore = true; + return 0; + } + return cmdline_parse_core(p, &required_kernelcore); } -- 2.30.2