]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm/swapfile: add cond_resched() in get_swap_pages()
authorLonglong Xia <xialonglong1@huawei.com>
Sat, 28 Jan 2023 09:47:57 +0000 (09:47 +0000)
committerAndrew Morton <akpm@linux-foundation.org>
Wed, 1 Feb 2023 00:44:10 +0000 (16:44 -0800)
commit7717fc1a12f88701573f9ed897cc4f6699c661e3
tree6bf7619e3a3861ca5d3834851d6e4232a861d4fc
parent993f57e0277b78182eb9e4955d118cc8b086c83d
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>
mm/swapfile.c