All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Rientjes <rientjes@google.com>
To: Michal Hocko <mhocko@suse.com>
Cc: Feng Tang <feng.tang@intel.com>,
	linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
	Christian Brauner <christian@brauner.io>,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH] mm/oom: detect and kill task which has allocation forbidden by cpuset limit
Date: Tue, 31 Aug 2021 18:06:17 -0700 (PDT)	[thread overview]
Message-ID: <52d80e9-cf27-9a59-94fd-d27a1e2dac6f@google.com> (raw)
In-Reply-To: <YS5RTiVgydjszmjn@dhcp22.suse.cz>

On Tue, 31 Aug 2021, Michal Hocko wrote:

> I do not like this solution TBH. We know that that it is impossible to
> satisfy the allocation at the page allocator level so dealing with it at
> the OOM killer level is just a bad layering and a lot of wasted cycles
> to reach that point. Why cannot we simply fail the allocation if cpusets
> filtering leads to an empty zone intersection?

Cpusets will guarantee our effective nodemask will include at least one 
node in N_MEMORY (cpuset_mems_allowed()) so we'll always have at least one 
zone in our zonelist.

Issue in this case appears to be that the zone will never satisfy 
non-movable allocations.  I think this would be very similar to a GFP_DMA 
allocation when bound to a node without lowmem, in which case we get a 
page allocation failure.  We don't kill current like this patch.

So I'd agree in this case that it would be better to simply fail the 
allocation.

Feng, would you move this check to __alloc_pages_may_oom() like the other 
special cases and simply fail rather than call into the oom killer?

  reply	other threads:[~2021-09-01  1:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31  8:38 [RFC PATCH] mm/oom: detect and kill task which has allocation forbidden by cpuset limit Feng Tang
2021-08-31 15:57 ` Michal Hocko
2021-09-01  1:06   ` David Rientjes [this message]
2021-09-01  1:06     ` David Rientjes
2021-09-01  2:44     ` Feng Tang
2021-09-01 13:42       ` Feng Tang
2021-09-01 14:05         ` Michal Hocko
2021-09-02  7:34           ` Feng Tang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=52d80e9-cf27-9a59-94fd-d27a1e2dac6f@google.com \
    --to=rientjes@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=christian@brauner.io \
    --cc=feng.tang@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.