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authorYang Yang <yang.yang29@zte.com.cn>2022-03-22 14:46:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-22 15:57:09 -0700
commit4d45c3aff5ebf80d329eba0f90544d20224f612d (patch)
treefc2d0043a99fe44608ed8f01da3cfa3e4f7365cb /mm/vmstat.c
parentd8c47cc7bf602ef73384a00869a70148146c1191 (diff)
mm/vmstat: add event for ksm swapping in copy
When faults in from swap what used to be a KSM page and that page had been swapped in before, system has to make a copy, and leaves remerging the pages to a later pass of ksmd. That is not good for performace, we'd better to reduce this kind of copy. There are some ways to reduce it, for example lessen swappiness or madvise(, , MADV_MERGEABLE) range. So add this event to support doing this tuning. Just like this patch: "mm, THP, swap: add THP swapping out fallback counting". Link: https://lkml.kernel.org/r/20220113023839.758845-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Cc: Hugh Dickins <hughd@google.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Saravanan D <saravanand@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmstat.c')
-rw-r--r--mm/vmstat.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 846b670dd346..d5cc8d739fac 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1388,6 +1388,9 @@ const char * const vmstat_text[] = {
#ifdef CONFIG_SWAP
"swap_ra",
"swap_ra_hit",
+#ifdef CONFIG_KSM
+ "ksm_swpin_copy",
+#endif
#endif
#ifdef CONFIG_X86
"direct_map_level2_splits",