openwrt/target/linux/generic/backport-5.15/020-v6.1-13-mm-mglru-don-t-sync-disk-for-each-aging-cycle.patch

From 92d430e8955c976eacb7cc91d7ff849c0dd009af Mon Sep 17 00:00:00 2001
From: Yu Zhao <yuzhao@google.com>
Date: Wed, 28 Sep 2022 13:36:58 -0600
Subject: [PATCH 13/29] mm/mglru: don't sync disk for each aging cycle

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
+++ b/mm/vmscan.c
@@ -4165,8 +4165,6 @@ done:
 	if (wq_has_sleeper(&lruvec->mm_state.wait))
 		wake_up_all(&lruvec->mm_state.wait);
 
-	wakeup_flusher_threads(WB_REASON_VMSCAN);
-
 	return true;
 }