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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2012-12-12 13:51:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-12 17:38:32 -0800
commitd8a8e1f0da3d29d7268b3300c96a059d63901b76 (patch)
tree46bd195f1cf4fd66c87f7d16c6bf043ad7fda9ff /Documentation/vm
parent97ae17497e996ff09bf97b6db3b33f7fd4029092 (diff)
downloadlinux-linaro-stable-d8a8e1f0da3d29d7268b3300c96a059d63901b76.tar.gz
thp, vmstat: implement HZP_ALLOC and HZP_ALLOC_FAILED events
hzp_alloc is incremented every time a huge zero page is successfully allocated. It includes allocations which where dropped due race with other allocation. Note, it doesn't count every map of the huge zero page, only its allocation. hzp_alloc_failed is incremented if kernel fails to allocate huge zero page and falls back to using small pages. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Cc: Mel Gorman <mel@csn.ul.ie> 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 'Documentation/vm')
-rw-r--r--Documentation/vm/transhuge.txt8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt
index 8f5b41db314c..60aeedd54615 100644
--- a/Documentation/vm/transhuge.txt
+++ b/Documentation/vm/transhuge.txt
@@ -197,6 +197,14 @@ thp_split is incremented every time a huge page is split into base
pages. This can happen for a variety of reasons but a common
reason is that a huge page is old and is being reclaimed.
+thp_zero_page_alloc is incremented every time a huge zero page is
+ successfully allocated. It includes allocations which where
+ dropped due race with other allocation. Note, it doesn't count
+ every map of the huge zero page, only its allocation.
+
+thp_zero_page_alloc_failed is incremented if kernel fails to allocate
+ huge zero page and falls back to using small pages.
+
As the system ages, allocating huge pages may be expensive as the
system uses memory compaction to copy data around memory to free a
huge page for use. There are some counters in /proc/vmstat to help