+ mm-mglru-dont-sync-disk-for-each-aging-cycle.patch added to mm-unstable branch

+ mm-mglru-dont-sync-disk-for-each-aging-cycle.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/mglru: don't sync disk for each aging cycle
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mglru-dont-sync-disk-for-each-aging-cycle.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mglru-dont-sync-disk-for-each-aging-cycle.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: Yu Zhao <yuzhao@google.com>
Subject: mm/mglru: don't sync disk for each aging cycle
Date: Wed, 28 Sep 2022 13:36:58 -0600

wakeup_flusher_threads() was added under the assumption that if a system
runs out of clean cold pages, it might want to write back dirty pages more
aggressively so that they can become clean and be dropped.

However, doing so can breach the rate limit a system wants to impose on
writeback, resulting in early SSD wearout.

Link: https://lkml.kernel.org/r/YzSiWq9UEER5LKup@google.com
Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks")
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reported-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmscan.c |    2 --
 1 file changed, 2 deletions(-)

--- a/mm/vmscan.c~mm-mglru-dont-sync-disk-for-each-aging-cycle
+++ a/mm/vmscan.c
@@ -4413,8 +4413,6 @@ done:
 	if (wq_has_sleeper(&lruvec->mm_state.wait))
 		wake_up_all(&lruvec->mm_state.wait);
 
-	wakeup_flusher_threads(WB_REASON_VMSCAN);
-
 	return true;
 }
 
_

Patches currently in -mm which might be from yuzhao@google.com are

mm-mglru-dont-sync-disk-for-each-aging-cycle.patch