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authorAlex Shi <alex.shi@intel.com>2012-08-21 16:16:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-08-21 16:45:03 -0700
commitb121186ab1b12e2a96a945d88eae0735b4542158 (patch)
tree9d142b77b090af2c508302457435f33143630a0b /mm
parent5ed12f12825c6c0451d703bfe918a7fc190e2738 (diff)
downloadlwn-b121186ab1b12e2a96a945d88eae0735b4542158.tar.gz
lwn-b121186ab1b12e2a96a945d88eae0735b4542158.zip
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')
-rw-r--r--mm/page_alloc.c21
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);