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| author | Christoph Lameter <cl@linux.com> | 2013-09-11 14:21:30 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-11 15:57:31 -0700 |
| commit | 2bb921e526656556e68f99f5f15a4a1bf2691844 (patch) | |
| tree | 91b009a59938d7713de0781df9d5c0c2eacfc51f /mm/page_alloc.c | |
| parent | d2cf5ad6312ca9913464fac40fb47ba47ad945c4 (diff) | |
| download | linux-2bb921e526656556e68f99f5f15a4a1bf2691844.tar.gz linux-2bb921e526656556e68f99f5f15a4a1bf2691844.tar.bz2 linux-2bb921e526656556e68f99f5f15a4a1bf2691844.zip | |
vmstat: create separate function to fold per cpu diffs into local counters
The main idea behind this patchset is to reduce the vmstat update overhead
by avoiding interrupt enable/disable and the use of per cpu atomics.
This patch (of 3):
It is better to have a separate folding function because
refresh_cpu_vm_stats() also does other things like expire pages in the
page allocator caches.
If we have a separate function then refresh_cpu_vm_stats() is only called
from the local cpu which allows additional optimizations.
The folding function is only called when a cpu is being downed and
therefore no other processor will be accessing the counters. Also
simplifies synchronization.
[akpm@linux-foundation.org: fix UP build]
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
CC: Tejun Heo <tj@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.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 | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 42c59300bacd..f885eb827159 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5435,7 +5435,7 @@ static int page_alloc_cpu_notify(struct notifier_block *self, * This is only okay since the processor is dead and cannot * race with what we are doing. */ - refresh_cpu_vm_stats(cpu); + cpu_vm_stats_fold(cpu); } return NOTIFY_OK; } |