Re: [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend

[Tejun Heo]

On Wed, Nov 05, 2014 at 11:54:28AM -0500, Tejun Heo wrote:
> > Still not following. How do you want to detect an on-going OOM without
> > any interface around out_of_memory?
> 
> I thought you were using oom_killer_allowed_start() outside OOM path.
> Ugh.... why is everything weirdly structured?  oom_killer_disabled
> implies that oom killer may fail, right?  Why is
> __alloc_pages_slowpath() checking it directly?  If whether oom killing
> failed or not is relevant to its users, make out_of_memory() return an
> error code.  There's no reason for the exclusion detail to leak out of
> the oom killer proper.  The only interface should be disable/enable
> and whether oom killing failed or not.

And what's implemented is wrong.  What happens if oom killing is
already in progress and then a task blocks trying to write-lock the
rwsem and then that task is selected as the OOM victim?  disable()
call must be able to fail.

-- 
tejun
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