The patch titled
Subject: mm, vmscan: don't turn on cache_trim_mode at the highest scan priority
has been added to the -mm mm-unstable branch. Its filename is
mm-vmscan-dont-turn-on-cache_trim_mode-at-the-highest-scan-priority.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmscan-dont-turn-on-cache_trim_mode-at-the-highest-scan-priority.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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------------------------------------------------------
From: Byungchul Park <byungchul@xxxxxx>
Subject: mm, vmscan: don't turn on cache_trim_mode at the highest scan priority
Date: Thu, 8 Feb 2024 15:18:25 +0900
With cache_trim_mode on, reclaim logic doesn't bother reclaiming anon
pages. However, it should be more careful to turn on the mode because
it's going to prevent anon pages from being reclaimed even if there are a
huge number of anon pages that are very cold and which should be
reclaimed. Even worse, that can lead kswapd_failures to reach
MAX_RECLAIM_RETRIES and stopping kswapd until direct reclaim eventually
works to resume kswapd.
Link: https://lkml.kernel.org/r/20240208061825.36640-1-byungchul@xxxxxx
Signed-off-by: Byungchul Park <byungchul@xxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmscan.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/vmscan.c~mm-vmscan-dont-turn-on-cache_trim_mode-at-the-highest-scan-priority
+++ a/mm/vmscan.c
@@ -2269,7 +2269,8 @@ static void prepare_scan_control(pg_data
* anonymous pages.
*/
file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE);
- if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE))
+ if (sc->priority != 1 && file >> sc->priority &&
+ !(sc->may_deactivate & DEACTIVATE_FILE))
sc->cache_trim_mode = 1;
else
sc->cache_trim_mode = 0;
_
Patches currently in -mm which might be from byungchul@xxxxxx are
mm-vmscan-dont-turn-on-cache_trim_mode-at-the-highest-scan-priority.patch
