This is a note to let you know that I've just added the patch titled
mm/swapfile: add cond_resched() in get_swap_pages()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-swapfile-add-cond_resched-in-get_swap_pages.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7717fc1a12f88701573f9ed897cc4f6699c661e3 Mon Sep 17 00:00:00 2001
From: Longlong Xia <xialonglong1@xxxxxxxxxx>
Date: Sat, 28 Jan 2023 09:47:57 +0000
Subject: mm/swapfile: add cond_resched() in get_swap_pages()
From: Longlong Xia <xialonglong1@xxxxxxxxxx>
commit 7717fc1a12f88701573f9ed897cc4f6699c661e3 upstream.
The softlockup still occurs in get_swap_pages() under memory pressure. 64
CPU cores, 64GB memory, and 28 zram devices, the disksize of each zram
device is 50MB with same priority as si. Use the stress-ng tool to
increase memory pressure, causing the system to oom frequently.
The plist_for_each_entry_safe() loops in get_swap_pages() could reach tens
of thousands of times to find available space (extreme case:
cond_resched() is not called in scan_swap_map_slots()). Let's add
cond_resched() into get_swap_pages() when failed to find available space
to avoid softlockup.
Link: https://lkml.kernel.org/r/20230128094757.1060525-1-xialonglong1@xxxxxxxxxx
Signed-off-by: Longlong Xia <xialonglong1@xxxxxxxxxx>
Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Chen Wandun <chenwandun@xxxxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Nanyong Sun <sunnanyong@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/swapfile.c | 1 +
1 file changed, 1 insertion(+)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1101,6 +1101,7 @@ start_over:
goto check_out;
pr_debug("scan_swap_map of si %d failed to find offset\n",
si->type);
+ cond_resched();
spin_lock(&swap_avail_lock);
nextsi:
Patches currently in stable-queue which might be from xialonglong1@xxxxxxxxxx are
queue-6.1/mm-swapfile-add-cond_resched-in-get_swap_pages.patch
