From b121186ab1b12e2a96a945d88eae0735b4542158 Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Tue, 21 Aug 2012 16:16:08 -0700 Subject: mm: correct page->pfmemalloc to fix deactivate_slab regression Commit cfd19c5a9ecf ("mm: only set page->pfmemalloc when ALLOC_NO_WATERMARKS was used") tried to narrow down page->pfmemalloc setting, but it missed some places the pfmemalloc should be set. So, in __slab_alloc, the unalignment pfmemalloc and ALLOC_NO_WATERMARKS cause incorrect deactivate_slab() on our core2 server: 64.73% fio [kernel.kallsyms] [k] _raw_spin_lock | --- _raw_spin_lock | |---0.34%-- deactivate_slab | __slab_alloc | kmem_cache_alloc | | That causes our fio sync write performance to have a 40% regression. Move the checking in get_page_from_freelist() which resolves this issue. Signed-off-by: Alex Shi Acked-by: Mel Gorman Cc: David Miller Tested-by: Eric Dumazet Tested-by: Sage Weil Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 009ac285fea7..07f19248acb5 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1928,6 +1928,17 @@ this_zone_full: zlc_active = 0; goto zonelist_scan; } + + if (page) + /* + * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was + * necessary to allocate the page. The expectation is + * that the caller is taking steps that will free more + * memory. The caller should avoid the page being used + * for !PFMEMALLOC purposes. + */ + page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS); + return page; } @@ -2389,14 +2400,6 @@ rebalance: zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); if (page) { - /* - * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was - * necessary to allocate the page. The expectation is - * that the caller is taking steps that will free more - * memory. The caller should avoid the page being used - * for !PFMEMALLOC purposes. - */ - page->pfmemalloc = true; goto got_pg; } } @@ -2569,8 +2572,6 @@ retry_cpuset: page = __alloc_pages_slowpath(gfp_mask, order, zonelist, high_zoneidx, nodemask, preferred_zone, migratetype); - else - page->pfmemalloc = false; trace_mm_page_alloc(page, order, gfp_mask, migratetype); -- cgit v1.2.3-59-g8ed1b