target/linux/generic/backport-5.15/021-v6.1-mm-mglru-don-t-sync-disk-for-each-aging-cycle.patch

   1 From 14aa8b2d5c2ebead01b542f62d68029023054774 Mon Sep 17 00:00:00 2001
   2 From: Yu Zhao <yuzhao@google.com>
   3 Date: Wed, 28 Sep 2022 13:36:58 -0600
   4 Subject: [PATCH 1/1] mm/mglru: don't sync disk for each aging cycle
   5
   6 wakeup_flusher_threads() was added under the assumption that if a system
   7 runs out of clean cold pages, it might want to write back dirty pages more
   8 aggressively so that they can become clean and be dropped.
   9
  10 However, doing so can breach the rate limit a system wants to impose on
  11 writeback, resulting in early SSD wearout.
  12
  13 Link: https://lkml.kernel.org/r/YzSiWq9UEER5LKup@google.com
  14 Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks")
  15 Signed-off-by: Yu Zhao <yuzhao@google.com>
  16 Reported-by: Axel Rasmussen <axelrasmussen@google.com>
  17 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  18 ---
  19  mm/vmscan.c | 2 --
  20  1 file changed, 2 deletions(-)
  21
  22 --- a/mm/vmscan.c
  23 +++ b/mm/vmscan.c
  24 @@ -4007,8 +4007,6 @@ static bool try_to_inc_max_seq(struct lr
  25         if (wq_has_sleeper(&lruvec->mm_walk.wait))
  26                 wake_up_all(&lruvec->mm_walk.wait);
  27
  28 -       wakeup_flusher_threads(WB_REASON_VMSCAN);
  29 -
  30         return true;
  31  }
  32