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authorYang Yang <yang.yang29@zte.com.cn>2022-08-15 07:28:37 +0000
committerAndrew Morton <akpm@linux-foundation.org>2022-09-26 19:46:08 -0700
commit3a9bb7b1879bef057a5dbff1dac1fa1411638064 (patch)
tree28c2876a44ea4f02422dc0f9ce709b4296ab3cb4 /mm/page_io.c
parentaa1cf99b87e934e761b46ce2b925335a398980da (diff)
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mm/page_io: count submission time as thrashing delay for delayacct
Once upon a time, we only support accounting thrashing of page cache. Then Joonsoo introduced workingset detection for anonymous pages and we gained the ability to account thrashing of them[1]. Likes PSI, we count submission time as thrashing delay because when the device is congested, or the submitting cgroup IO-throttled, submission can be a significant part of overall IO time. Without this patch, swap thrashing through frontswap or some block device supporting rw_page operation isn't measured correctly. This patch is based on "delayacct: support re-entrance detection of thrashing accounting". [1] commit aae466b0052e ("mm/swap: implement workingset detection for anonymous LRU") Link: https://lkml.kernel.org/r/20220815072835.74876-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: CGEL ZTE <cgel.zte@gmail.com> Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Reviewed-by: wangyong <wang.yong12@zte.com.cn> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_io.c')
-rw-r--r--mm/page_io.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/mm/page_io.c b/mm/page_io.c
index 68d53fc27598..fc6b3fb1f7c5 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -452,18 +452,21 @@ int swap_readpage(struct page *page, bool synchronous,
struct swap_info_struct *sis = page_swap_info(page);
bool workingset = PageWorkingset(page);
unsigned long pflags;
+ bool in_thrashing;
VM_BUG_ON_PAGE(!PageSwapCache(page) && !synchronous, page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageUptodate(page), page);
/*
- * Count submission time as memory stall. When the device is congested,
- * or the submitting cgroup IO-throttled, submission can be a
- * significant part of overall IO time.
+ * Count submission time as memory stall and delay. When the device
+ * is congested, or the submitting cgroup IO-throttled, submission
+ * can be a significant part of overall IO time.
*/
- if (workingset)
+ if (workingset) {
+ delayacct_thrashing_start(&in_thrashing);
psi_memstall_enter(&pflags);
+ }
delayacct_swapin_start();
if (frontswap_load(page) == 0) {
@@ -512,8 +515,10 @@ int swap_readpage(struct page *page, bool synchronous,
bio_put(bio);
out:
- if (workingset)
+ if (workingset) {
+ delayacct_thrashing_end(&in_thrashing);
psi_memstall_leave(&pflags);
+ }
delayacct_swapin_end();
return ret;
}