From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Michal Hocko <mhocko@kernel.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch] mm, oom: prevent soft lockup on memcg oom for UP systems
Date: Thu, 12 Mar 2020 09:12:14 +0900 [thread overview]
Message-ID: <202003120012.02C0CEUB043533@www262.sakura.ne.jp> (raw)
In-Reply-To: <alpine.DEB.2.21.2003111513180.195367@chino.kir.corp.google.com>
> On Thu, 12 Mar 2020, Tetsuo Handa wrote:
> > > If you have an alternate patch to try, we can test it. But since this
> > > cond_resched() is needed anyway, I'm not sure it will change the result.
> >
> > schedule_timeout_killable(1) is an alternate patch to try; I don't think
> > that this cond_resched() is needed anyway.
> >
>
> You are suggesting schedule_timeout_killable(1) in shrink_node_memcgs()?
>
Andrew Morton also mentioned whether cond_resched() in shrink_node_memcgs()
is enough. But like you mentioned,
David Rientjes wrote:
> On Tue, 10 Mar 2020, Andrew Morton wrote:
>
> > > --- a/mm/vmscan.c
> > > +++ b/mm/vmscan.c
> > > @@ -2637,6 +2637,8 @@ static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc)
> > > unsigned long reclaimed;
> > > unsigned long scanned;
> > >
> > > + cond_resched();
> > > +
> > > switch (mem_cgroup_protected(target_memcg, memcg)) {
> > > case MEMCG_PROT_MIN:
> > > /*
> >
> >
> > Obviously better, but this will still spin wheels until this tasks's
> > timeslice expires, and we might want to do something to help ensure
> > that the victim runs next (or soon)?
> >
>
> We used to have a schedule_timeout_killable(1) to address exactly that
> scenario but it was removed in 4.19:
>
> commit 9bfe5ded054b8e28a94c78580f233d6879a00146
> Author: Michal Hocko <mhocko@suse.com>
> Date: Fri Aug 17 15:49:04 2018 -0700
>
> mm, oom: remove sleep from under oom_lock
you can try re-adding sleep outside of oom_lock:
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d09776cd6e10..3aee7e0eca4e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1576,6 +1576,7 @@ static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
*/
ret = should_force_charge() || out_of_memory(&oc);
mutex_unlock(&oom_lock);
+ schedule_timeout_killable(1);
return ret;
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3c4eb750a199..e80158049651 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3797,7 +3797,6 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
*/
if (!mutex_trylock(&oom_lock)) {
*did_some_progress = 1;
- schedule_timeout_uninterruptible(1);
return NULL;
}
@@ -4590,6 +4589,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
/* Retry as long as the OOM killer is making progress */
if (did_some_progress) {
+ schedule_timeout_uninterruptible(1);
no_progress_loops = 0;
goto retry;
}
By the way, will you share the reproducer (and how to use the reproducer) ?
next prev parent reply other threads:[~2020-03-12 0:12 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-10 21:39 [patch] mm, oom: prevent soft lockup on memcg oom for UP systems David Rientjes
2020-03-10 22:05 ` Tetsuo Handa
2020-03-10 22:55 ` David Rientjes
2020-03-11 9:34 ` Tetsuo Handa
2020-03-11 19:38 ` David Rientjes
2020-03-11 22:04 ` Tetsuo Handa
2020-03-11 22:14 ` David Rientjes
2020-03-12 0:12 ` Tetsuo Handa [this message]
2020-03-12 18:07 ` David Rientjes
2020-03-12 22:32 ` Andrew Morton
2020-03-16 9:31 ` Michal Hocko
2020-03-16 10:04 ` Tetsuo Handa
2020-03-16 10:14 ` Michal Hocko
2020-03-13 0:15 ` Tetsuo Handa
2020-03-13 22:01 ` David Rientjes
2020-03-13 23:15 ` Tetsuo Handa
2020-03-13 23:32 ` Tetsuo Handa
2020-03-16 23:59 ` David Rientjes
2020-03-17 3:18 ` Tetsuo Handa
2020-03-17 4:09 ` David Rientjes
2020-03-18 0:55 ` [patch v2] " David Rientjes
2020-03-18 9:42 ` Michal Hocko
2020-03-18 21:40 ` David Rientjes
2020-03-18 22:03 ` [patch v3] " David Rientjes
2020-03-19 7:09 ` Michal Hocko
2020-03-12 4:23 ` [patch] " Tetsuo Handa
2020-03-10 22:10 ` Michal Hocko
2020-03-10 23:02 ` David Rientjes
2020-03-11 8:27 ` Michal Hocko
2020-03-11 19:45 ` David Rientjes
2020-03-12 8:32 ` Michal Hocko
2020-03-12 18:20 ` David Rientjes
2020-03-12 20:16 ` Michal Hocko
2020-03-16 9:32 ` Michal Hocko
2020-03-11 0:18 ` Andrew Morton
2020-03-11 0:34 ` David Rientjes
2020-03-11 8:36 ` Michal Hocko
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