+ mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2.patch added to mm-hotfixes-unstable branch

+ mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2.patch

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

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------------------------------------------------------
From: Li Zhijian <lizhijian@fujitsu.com>
Subject: mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2
Date: Sat, 11 Jan 2025 09:52:53 +0800

introduce local nr_demoted to fix nr_reclaimed double counting

Link: https://lkml.kernel.org/r/20250111015253.425693-1-lizhijian@fujitsu.com
Fixes: f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA balancing operations")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Cc: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmscan.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/mm/vmscan.c~mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2
+++ a/mm/vmscan.c
@@ -1053,7 +1053,7 @@ static unsigned int shrink_folio_list(st
 	struct folio_batch free_folios;
 	LIST_HEAD(ret_folios);
 	LIST_HEAD(demote_folios);
-	unsigned int nr_reclaimed = 0;
+	unsigned int nr_reclaimed = 0, nr_demoted = 0;
 	unsigned int pgactivate = 0;
 	bool do_demote_pass;
 	struct swap_iocb *plug = NULL;
@@ -1522,8 +1522,9 @@ keep:
 	/* 'folio_list' is always empty here */
 
 	/* Migrate folios selected for demotion */
-	stat->nr_demoted += demote_folio_list(&demote_folios, pgdat);
-	nr_reclaimed += stat->nr_demoted;
+	nr_demoted = demote_folio_list(&demote_folios, pgdat);
+	nr_reclaimed += nr_demoted;
+	stat->nr_demoted += nr_demoted;
 	/* Folios that could not be demoted are still in @demote_folios */
 	if (!list_empty(&demote_folios)) {
 		/* Folios which weren't demoted go back on @folio_list */
_

Patches currently in -mm which might be from lizhijian@fujitsu.com are

mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics.patch
mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2.patch
mm-vmscan-fix-pgdemote_-accounting-with-lru_gen_enabled.patch
selftests-mm-add-a-few-missing-gitignore-files.patch

Re: + mm-vmscan-accumulate-nr_demoted-for-accurate-demotion-statistics-v2.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

On Sun, 26 Jan 2025 04:14:22 +0000 "Zhijian Li (Fujitsu)" <lizhijian@fujitsu.com> wrote:

> Hi Andrew
> 
> I just noticed this patch was not included in -mm PR for v6.14-rc1[1]
> 
> However, our product needs to incorporate this patch as soon as possible. So I would like to ask if it can make it catch up 6.14?

Note that is was added to mm.git's hotfixes branch.  So expect this to
be sent into Linus as a hot fix within the next week.

Note also that the patch has cc:stable, so expect the -stable
maintainers to backport it into -stable trees as appropriate.