Re: [PATCH v8] oom_kill.c: futex: Don't OOM reap the VMA containing the robust_list_head

Michal Hocko
2022-04-08T09:36:46Z

On Fri 08-04-22 04:52:33, Nico Pache wrote:
[...]
> In a heavily contended CPU with high memory pressure the delay may also
> lead to other processes unnecessarily OOMing.

Let me just comment on this part because there is likely a confusion
inlved. Delaying the oom_reaper _cannot_ lead to additional OOM killing
because the the oom killing is throttled by existence of a preexisting
OOM victim. In other words as long as there is an alive victim no
further victims are not selected and the oom killer backs off. The
oom_repaer will hide the alive oom victim after it is processed.
The longer the delay will be the longer an oom victim can block a
further progress but it cannot really cause unnecessary OOMing.
--
Michal Hocko
SUSE Labs