Messages in this thread | | | From | "Huang, Ying" <> | Subject | Re: [PATCH] mm/swapfile: add cond_resched() in get_swap_pages() | Date | Sun, 29 Jan 2023 08:39:21 +0800 |
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Longlong Xia <xialonglong1@huawei.com> writes:
> 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. > > Signed-off-by: Longlong Xia <xialonglong1@huawei.com>
Looks good to me. Thanks!
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
> --- > mm/swapfile.c | 1 + > 1 file changed, 1 insertion(+) > > 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 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size) > 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:
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