Re: [PATCH] mm/page_alloc: try oom if reclaim is unable to make forward progress

[Aaron Tomlin]

Michal,

On Wed 2021-05-19 13:10 +0200, Michal Hocko wrote:
> > Looking at try_to_compact_pages(), indeed COMPACT_SKIPPED can be returned;
> > albeit, not every zone, on the zone list, would be considered in the case
> > a fatal signal is found to be pending. Yet, in should_compact_retry(),
> > given the last known compaction result, each zone, on the zone list, can be
> > considered/or checked (see compaction_zonelist_suitable()). If a zone e.g.
> > was found to succeed then reclaim/compaction would be tried again
> > (notwithstanding the above).
> 
> I believe Vlastimil would be much better fit into looking into those
> details but it smells like pending fatal signals can lead to a unbound
> retry indeed.

Understood.

I will post a trivial patch to hopefully address this particular condition
in the compaction retry code path, shortly for further discussion.


Kind regards,

-- 
Aaron Tomlin