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authorLonglong Xia <xialonglong1@huawei.com>2023-01-28 12:47:57 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-02-09 13:28:22 +0300
commit49178d4d61e78aed8c837dfeea8a450700f196e2 (patch)
tree92b3294a55ef256991eaff72753b664ddd31ea87 /mm
parent2d11727655bf931776fb541f5862daf04bd5bf02 (diff)
downloadlinux-49178d4d61e78aed8c837dfeea8a450700f196e2.tar.xz
mm/swapfile: add cond_resched() in get_swap_pages()
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@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 72e481aacd5d..b72908df52ac 100644
--- 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: