diff options
| author |   Yang Yang <yang.yang29@zte.com.cn> | 2022-03-22 14:46:33 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 15:57:09 -0700 |
| commit | 4d45c3aff5ebf80d329eba0f90544d20224f612d (patch) | |
| tree | fc2d0043a99fe44608ed8f01da3cfa3e4f7365cb /mm/vmstat.c | |
| parent | mm: page_io: fix psi memory pressure error on cold swapins (diff) | |
| download | linux-dev-4d45c3aff5ebf80d329eba0f90544d20224f612d.tar.xz linux-dev-4d45c3aff5ebf80d329eba0f90544d20224f612d.zip | |
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.c | 3 |
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", |