diff options
author | Jianguo Wu <wujianguo@huawei.com> | 2012-10-09 01:33:06 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-09 09:22:54 +0200 |
commit | 7f1290f2f2a4d2c3f1b7ce8e87256e052ca23125 (patch) | |
tree | 10328fcb468647ba678e022911d5c2005080f309 /mm | |
parent | mm: enable CONFIG_COMPACTION by default (diff) | |
download | linux-7f1290f2f2a4d2c3f1b7ce8e87256e052ca23125.tar.xz linux-7f1290f2f2a4d2c3f1b7ce8e87256e052ca23125.zip |
mm: fix-up zone present pages
I think zone->present_pages indicates pages that buddy system can management,
it should be:
zone->present_pages = spanned pages - absent pages - bootmem pages,
but is now:
zone->present_pages = spanned pages - absent pages - memmap pages.
spanned pages: total size, including holes.
absent pages: holes.
bootmem pages: pages used in system boot, managed by bootmem allocator.
memmap pages: pages used by page structs.
This may cause zone->present_pages less than it should be. For example,
numa node 1 has ZONE_NORMAL and ZONE_MOVABLE, it's memmap and other
bootmem will be allocated from ZONE_MOVABLE, so ZONE_NORMAL's
present_pages should be spanned pages - absent pages, but now it also
minus memmap pages(free_area_init_core), which are actually allocated from
ZONE_MOVABLE. When offlining all memory of a zone, this will cause
zone->present_pages less than 0, because present_pages is unsigned long
type, it is actually a very large integer, it indirectly caused
zone->watermark[WMARK_MIN] becomes a large
integer(setup_per_zone_wmarks()), than cause totalreserve_pages become a
large integer(calculate_totalreserve_pages()), and finally cause memory
allocating failure when fork process(__vm_enough_memory()).
[root@localhost ~]# dmesg
-bash: fork: Cannot allocate memory
I think the bug described in
http://marc.info/?l=linux-mm&m=134502182714186&w=2
is also caused by wrong zone present pages.
This patch intends to fix-up zone->present_pages when memory are freed to
buddy system on x86_64 and IA64 platforms.
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Reported-by: Petr Tesarik <ptesarik@suse.cz>
Tested-by: Petr Tesarik <ptesarik@suse.cz>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/bootmem.c | 10 | ||||
-rw-r--r-- | mm/memory_hotplug.c | 7 | ||||
-rw-r--r-- | mm/nobootmem.c | 3 | ||||
-rw-r--r-- | mm/page_alloc.c | 34 |
4 files changed, 53 insertions, 1 deletions
diff --git a/mm/bootmem.c b/mm/bootmem.c index f468185b3b28..434be4ae7a04 100644 --- a/mm/bootmem.c +++ b/mm/bootmem.c @@ -198,6 +198,8 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata) int order = ilog2(BITS_PER_LONG); __free_pages_bootmem(pfn_to_page(start), order); + fixup_zone_present_pages(page_to_nid(pfn_to_page(start)), + start, start + BITS_PER_LONG); count += BITS_PER_LONG; start += BITS_PER_LONG; } else { @@ -208,6 +210,9 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata) if (vec & 1) { page = pfn_to_page(start + off); __free_pages_bootmem(page, 0); + fixup_zone_present_pages( + page_to_nid(page), + start + off, start + off + 1); count++; } vec >>= 1; @@ -221,8 +226,11 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata) pages = bdata->node_low_pfn - bdata->node_min_pfn; pages = bootmem_bootmap_pages(pages); count += pages; - while (pages--) + while (pages--) { + fixup_zone_present_pages(page_to_nid(page), + page_to_pfn(page), page_to_pfn(page) + 1); __free_pages_bootmem(page++, 0); + } bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index f9ac0955e10a..ce690a911f1b 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -106,6 +106,7 @@ static void get_page_bootmem(unsigned long info, struct page *page, void __ref put_page_bootmem(struct page *page) { unsigned long type; + struct zone *zone; type = (unsigned long) page->lru.next; BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || @@ -116,6 +117,12 @@ void __ref put_page_bootmem(struct page *page) set_page_private(page, 0); INIT_LIST_HEAD(&page->lru); __free_pages_bootmem(page, 0); + + zone = page_zone(page); + zone_span_writelock(zone); + zone->present_pages++; + zone_span_writeunlock(zone); + totalram_pages++; } } diff --git a/mm/nobootmem.c b/mm/nobootmem.c index bd82f6b31411..714d5d650470 100644 --- a/mm/nobootmem.c +++ b/mm/nobootmem.c @@ -116,6 +116,8 @@ static unsigned long __init __free_memory_core(phys_addr_t start, return 0; __free_pages_memory(start_pfn, end_pfn); + fixup_zone_present_pages(pfn_to_nid(start >> PAGE_SHIFT), + start_pfn, end_pfn); return end_pfn - start_pfn; } @@ -126,6 +128,7 @@ unsigned long __init free_low_memory_core_early(int nodeid) phys_addr_t start, end, size; u64 i; + reset_zone_present_pages(); for_each_free_mem_range(i, MAX_NUMNODES, &start, &end, NULL) count += __free_memory_core(start, end); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8ac593893e6e..00750bc08a3a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6087,3 +6087,37 @@ void dump_page(struct page *page) dump_page_flags(page->flags); mem_cgroup_print_bad_page(page); } + +/* reset zone->present_pages */ +void reset_zone_present_pages(void) +{ + struct zone *z; + int i, nid; + + for_each_node_state(nid, N_HIGH_MEMORY) { + for (i = 0; i < MAX_NR_ZONES; i++) { + z = NODE_DATA(nid)->node_zones + i; + z->present_pages = 0; + } + } +} + +/* calculate zone's present pages in buddy system */ +void fixup_zone_present_pages(int nid, unsigned long start_pfn, + unsigned long end_pfn) +{ + struct zone *z; + unsigned long zone_start_pfn, zone_end_pfn; + int i; + + for (i = 0; i < MAX_NR_ZONES; i++) { + z = NODE_DATA(nid)->node_zones + i; + zone_start_pfn = z->zone_start_pfn; + zone_end_pfn = zone_start_pfn + z->spanned_pages; + + /* if the two regions intersect */ + if (!(zone_start_pfn >= end_pfn || zone_end_pfn <= start_pfn)) + z->present_pages += min(end_pfn, zone_end_pfn) - + max(start_pfn, zone_start_pfn); + } +} |