lkml.org 
[lkml]   [2014]   [Nov]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 3/4] OOM, PM: OOM killed task shouldn't escape PM suspend
On Wed, Nov 05, 2014 at 05:39:56PM +0100, Michal Hocko wrote:
> On Wed 05-11-14 11:29:29, Tejun Heo wrote:
> > Hello, Michal.
> >
> > On Wed, Nov 05, 2014 at 05:01:15PM +0100, Michal Hocko wrote:
> > > I am not sure I am following. With the latest patch OOM path is no
> > > longer blocked by the PM (aka oom_killer_disable()). Allocations simply
> > > fail if the read_trylock fails.
> > > oom_killer_disable is moved before tasks are frozen and it will wait for
> > > all on-going OOM killers on the write lock. OOM killer is enabled again
> > > on the resume path.
> >
> > Sure, but why are we exposing new interfaces? Can't we just make
> > oom_killer_disable() first set the disable flag and wait for the
> > on-going ones to finish (and make the function fail if it gets chosen
> > as an OOM victim)?
>
> 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.

Thanks.

--
tejun


\
 
 \ /
  Last update: 2014-11-05 18:01    [W:0.442 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site