The quilt patch titled
Subject: mm/page_io: count submission time as thrashing delay for delayacct
has been removed from the -mm tree. Its filename was
mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Yang Yang <yang.yang29@xxxxxxxxxx>
Subject: mm/page_io: count submission time as thrashing delay for delayacct
Date: Mon, 15 Aug 2022 07:28:37 +0000
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@xxxxxxxxxx
Signed-off-by: Yang Yang <yang.yang29@xxxxxxxxxx>
Signed-off-by: CGEL ZTE <cgel.zte@xxxxxxxxx>
Reviewed-by: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
Reviewed-by: wangyong <wang.yong12@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_io.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
--- a/mm/page_io.c~mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct
+++ a/mm/page_io.c
@@ -452,18 +452,21 @@ int swap_readpage(struct page *page, boo
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, boo
bio_put(bio);
out:
- if (workingset)
+ if (workingset) {
+ delayacct_thrashing_end(&in_thrashing);
psi_memstall_leave(&pflags);
+ }
delayacct_swapin_end();
return ret;
}
_
Patches currently in -mm which might be from yang.yang29@xxxxxxxxxx are
