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authorLonglong Xia <xialonglong1@huawei.com>2023-01-28 09:47:57 +0000
committerAndrew Morton <akpm@linux-foundation.org>2023-01-31 16:44:10 -0800
commit7717fc1a12f88701573f9ed897cc4f6699c661e3 (patch)
tree6bf7619e3a3861ca5d3834851d6e4232a861d4fc /mm
parent993f57e0277b78182eb9e4955d118cc8b086c83d (diff)
mm/swapfile: add cond_resched() in get_swap_pages()
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@huawei.com Signed-off-by: Longlong Xia <xialonglong1@huawei.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Chen Wandun <chenwandun@huawei.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/swapfile.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 908a529bca12..4fa440e87cd6 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1100,6 +1100,7 @@ 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: