Re: [PATCH v3] mm/oom_kill: show oom eligibility when displaying the current memory state of all tasks

From: Aaron Tomlin
Date: Tue Aug 03 2021 - 06:32:38 EST


On Tue 2021-08-03 09:05 +0200, Michal Hocko wrote:
> There were some attempts to print oom_score during OOM. E.g.
> http://lkml.kernel.org/r/20190808183247.28206-1-echron@xxxxxxxxxx. That
> one was rejected on the grounds that the number on its own doesn't
> really present any real value. It is really only valuable when comparing
> to other potential oom victims. I have to say I am still worried about
> printing this internal scoring as it should have really been an
> implementation detail but with /proc/<pid>/oom_score this is likely a
> lost battle and I am willing to give up on that front.

Understood.

> I am still not entirely convinced this is worth doing though.
> oom_badness is not a cheap operation. task_lock has to be taken again
> during dump_tasks for each task so the already quite expensive operation
> will be more so. Is this really something we cannot live without?

Fair enough and I now agree, it is unquestionably not worth it.



Kind regards,

--
Aaron Tomlin