From: Michal Hocko <mhocko@suse.com>
To: Aaron Tomlin <atomlin@redhat.com>
Cc: linux-mm@kvack.org, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/page_alloc: try oom if reclaim is unable to make forward progress
Date: Mon, 22 Mar 2021 11:47:45 +0100 [thread overview]
Message-ID: <YFh10eSTKY5lbE9u@dhcp22.suse.cz> (raw)
In-Reply-To: <20210319172901.cror2u53b7caws3a@ava.usersys.com>
On Fri 19-03-21 17:29:01, Aaron Tomlin wrote:
> Hi Michal,
>
> On Thu 2021-03-18 17:16 +0100, Michal Hocko wrote:
> > On Mon 15-03-21 16:58:37, Aaron Tomlin wrote:
> > > In the situation where direct reclaim is required to make progress for
> > > compaction but no_progress_loops is already over the limit of
> > > MAX_RECLAIM_RETRIES consider invoking the oom killer.
>
> Firstly, thank you for your response.
>
> > What is the problem you are trying to fix?
>
> If I understand correctly, in the case of a "costly" order allocation
> request that is permitted to repeatedly retry, it is possible to exceed the
> maximum reclaim retry threshold as long as "some" progress is being made
> even at the highest compaction priority.
Costly orders already do have heuristics for the retry in place. Could
you be more specific what kind of problem you see with those?
> Furthermore, if the allocator has a fatal signal pending, this is not
> considered.
Fatal signals pending are usually not a strong reason to cut retries
count or fail allocations.
> In my opinion, it might be better to just give up straight away or try and
> use the OOM killer only in the non-costly order allocation scenario to
> assit reclaim. Looking at __alloc_pages_may_oom() the current logic is to
> entirely skip the OOM killer for a costly order request, which makes sense.
Well, opinions might differ of course. The main question is whether
there are workloads which are unhappy about the existing behavior.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2021-03-22 10:48 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-15 16:58 [PATCH] mm/page_alloc: try oom if reclaim is unable to make forward progress Aaron Tomlin
2021-03-15 19:54 ` kernel test robot
2021-03-15 19:54 ` kernel test robot
2021-03-15 19:54 ` kernel test robot
2021-03-18 16:16 ` Michal Hocko
2021-03-19 17:29 ` Aaron Tomlin
2021-03-22 10:47 ` Michal Hocko [this message]
2021-03-25 21:01 ` Aaron Tomlin
2021-03-26 8:16 ` Michal Hocko
2021-03-26 11:22 ` Aaron Tomlin
2021-03-26 15:36 ` Michal Hocko
2021-03-26 17:00 ` Aaron Tomlin
2021-05-18 14:05 ` Aaron Tomlin
2021-05-19 11:10 ` Michal Hocko
2021-05-19 13:06 ` Aaron Tomlin
2021-05-19 14:50 ` [PATCH] mm/page_alloc: bail out on fatal signal during reclaim/compaction retry attempt Aaron Tomlin
2021-05-19 15:22 ` Vlastimil Babka
2021-05-19 19:08 ` Aaron Tomlin
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