From: Jon Tollefson Date: Thu, 9 Oct 2008 10:18:40 +0000 (+0000) Subject: powerpc: Reserve in bootmem lmb reserved regions that cross NUMA nodes X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=8f64e1f2d1e09267ac926e15090fd505c1c0cbcb;p=openwrt%2Fstaging%2Fblogic.git powerpc: Reserve in bootmem lmb reserved regions that cross NUMA nodes If there are multiple reserved memory blocks via lmb_reserve() that are contiguous addresses and on different NUMA nodes we are losing track of which address ranges to reserve in bootmem on which node. I discovered this when I recently got to try 16GB huge pages on a system with more then 2 nodes. When scanning the device tree in early boot we call lmb_reserve() with the addresses of the 16G pages that we find so that the memory doesn't get used for something else. For example the addresses for the pages could be 4000000000, 4400000000, 4800000000, 4C00000000, etc - 8 pages, one on each of eight nodes. In the lmb after all the pages have been reserved it will look something like the following: lmb_dump_all: memory.cnt = 0x2 memory.size = 0x3e80000000 memory.region[0x0].base = 0x0 .size = 0x1e80000000 memory.region[0x1].base = 0x4000000000 .size = 0x2000000000 reserved.cnt = 0x5 reserved.size = 0x3e80000000 reserved.region[0x0].base = 0x0 .size = 0x7b5000 reserved.region[0x1].base = 0x2a00000 .size = 0x78c000 reserved.region[0x2].base = 0x328c000 .size = 0x43000 reserved.region[0x3].base = 0xf4e8000 .size = 0xb18000 reserved.region[0x4].base = 0x4000000000 .size = 0x2000000000 The reserved.region[0x4] contains the 16G pages. In arch/powerpc/mm/num.c: do_init_bootmem() we loop through each of the node numbers looking for the reserved regions that belong to the particular node. It is not able to identify region 0x4 as being a part of each of the 8 nodes. It is assuming that a reserved region is only on a single node. This patch takes out the reserved region loop from inside the loop that goes over each node. It looks up the active region containing the start of the reserved region. If it extends past that active region then it adjusts the size and gets the next active region containing it. Signed-off-by: Jon Tollefson Signed-off-by: Benjamin Herrenschmidt --- diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index be05457631d4..6cf5c71c431f 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -89,6 +89,46 @@ static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn, return 0; } +/* + * get_active_region_work_fn - A helper function for get_node_active_region + * Returns datax set to the start_pfn and end_pfn if they contain + * the initial value of datax->start_pfn between them + * @start_pfn: start page(inclusive) of region to check + * @end_pfn: end page(exclusive) of region to check + * @datax: comes in with ->start_pfn set to value to search for and + * goes out with active range if it contains it + * Returns 1 if search value is in range else 0 + */ +static int __init get_active_region_work_fn(unsigned long start_pfn, + unsigned long end_pfn, void *datax) +{ + struct node_active_region *data; + data = (struct node_active_region *)datax; + + if (start_pfn <= data->start_pfn && end_pfn > data->start_pfn) { + data->start_pfn = start_pfn; + data->end_pfn = end_pfn; + return 1; + } + return 0; + +} + +/* + * get_node_active_region - Return active region containing start_pfn + * @start_pfn: The page to return the region for. + * @node_ar: Returned set to the active region containing start_pfn + */ +static void __init get_node_active_region(unsigned long start_pfn, + struct node_active_region *node_ar) +{ + int nid = early_pfn_to_nid(start_pfn); + + node_ar->nid = nid; + node_ar->start_pfn = start_pfn; + work_with_active_regions(nid, get_active_region_work_fn, node_ar); +} + static void __cpuinit map_cpu_to_node(int cpu, int node) { numa_cpu_lookup_table[cpu] = node; @@ -882,38 +922,50 @@ void __init do_init_bootmem(void) start_pfn, end_pfn); free_bootmem_with_active_regions(nid, end_pfn); + } - /* Mark reserved regions on this node */ - for (i = 0; i < lmb.reserved.cnt; i++) { - unsigned long physbase = lmb.reserved.region[i].base; - unsigned long size = lmb.reserved.region[i].size; - unsigned long start_paddr = start_pfn << PAGE_SHIFT; - unsigned long end_paddr = end_pfn << PAGE_SHIFT; - - if (early_pfn_to_nid(physbase >> PAGE_SHIFT) != nid && - early_pfn_to_nid((physbase+size-1) >> PAGE_SHIFT) != nid) - continue; - - if (physbase < end_paddr && - (physbase+size) > start_paddr) { - /* overlaps */ - if (physbase < start_paddr) { - size -= start_paddr - physbase; - physbase = start_paddr; - } - - if (size > end_paddr - physbase) - size = end_paddr - physbase; - - dbg("reserve_bootmem %lx %lx\n", physbase, - size); - reserve_bootmem_node(NODE_DATA(nid), physbase, - size, BOOTMEM_DEFAULT); - } + /* Mark reserved regions */ + for (i = 0; i < lmb.reserved.cnt; i++) { + unsigned long physbase = lmb.reserved.region[i].base; + unsigned long size = lmb.reserved.region[i].size; + unsigned long start_pfn = physbase >> PAGE_SHIFT; + unsigned long end_pfn = ((physbase + size) >> PAGE_SHIFT); + struct node_active_region node_ar; + + get_node_active_region(start_pfn, &node_ar); + while (start_pfn < end_pfn) { + /* + * if reserved region extends past active region + * then trim size to active region + */ + if (end_pfn > node_ar.end_pfn) + size = (node_ar.end_pfn << PAGE_SHIFT) + - (start_pfn << PAGE_SHIFT); + dbg("reserve_bootmem %lx %lx nid=%d\n", physbase, size, + node_ar.nid); + reserve_bootmem_node(NODE_DATA(node_ar.nid), physbase, + size, BOOTMEM_DEFAULT); + /* + * if reserved region is contained in the active region + * then done. + */ + if (end_pfn <= node_ar.end_pfn) + break; + + /* + * reserved region extends past the active region + * get next active region that contains this + * reserved region + */ + start_pfn = node_ar.end_pfn; + physbase = start_pfn << PAGE_SHIFT; + get_node_active_region(start_pfn, &node_ar); } - sparse_memory_present_with_active_regions(nid); } + + for_each_online_node(nid) + sparse_memory_present_with_active_regions(nid); } void __init paging_init(void)