+ mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct.patch added to mm-unstable branch

+ mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/page_io: count submission time as thrashing delay for delayacct
has been added to the -mm mm-unstable branch.  Its filename is
     mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Yang Yang <yang.yang29@zte.com.cn>
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.

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>
---

 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@zte.com.cn are

mm-vmscan-define-macros-for-refaults-in-struct-lruvec.patch
filemap-make-the-accounting-of-thrashing-more-consistent.patch
mm-vmscan-make-the-annotations-of-refaults-code-at-the-right-place.patch
delayacct-support-re-entrance-detection-of-thrashing-accounting.patch
mm-page_io-count-submission-time-as-thrashing-delay-for-delayacct.patch