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| author | Alex Shi <alex.shi@intel.com> | 2012-08-21 16:16:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-08-21 16:45:03 -0700 |
| commit | b121186ab1b12e2a96a945d88eae0735b4542158 (patch) | |
| tree | 9d142b77b090af2c508302457435f33143630a0b /mm/page_alloc.c | |
| parent | 5ed12f12825c6c0451d703bfe918a7fc190e2738 (diff) | |
| download | linux-b121186ab1b12e2a96a945d88eae0735b4542158.tar.bz2 | |
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 <alex.shi@intel.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: David Miller <davem@davemloft.net
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Sage Weil <sage@inktank.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 21 |
1 files changed, 11 insertions, 10 deletions
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); |