From: Michal Hocko <mhocko@suse.com>
To: xunlei <xlpang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
Andrew Morton <akpm@linux-foundation.org>,
Vladimir Davydov <vdavydov.dev@gmail.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] mm: memcg: Fix memcg reclaim soft lockup
Date: Wed, 26 Aug 2020 13:00:15 +0200 [thread overview]
Message-ID: <20200826110015.GO22869@dhcp22.suse.cz> (raw)
In-Reply-To: <99efed0e-050a-e313-46ab-8fe6228839d5@linux.alibaba.com>
On Wed 26-08-20 18:41:18, xunlei wrote:
> On 2020/8/26 下午4:11, Michal Hocko wrote:
> > On Wed 26-08-20 15:27:02, Xunlei Pang wrote:
> >> We've met softlockup with "CONFIG_PREEMPT_NONE=y", when
> >> the target memcg doesn't have any reclaimable memory.
> >
> > Do you have any scenario when this happens or is this some sort of a
> > test case?
>
> It can happen on tiny guest scenarios.
OK, you made me more curious. If this is a tiny guest and this is a hard
limit reclaim path then we should trigger an oom killer which should
kill the offender and that in turn bail out from the try_charge lopp
(see should_force_charge). So how come this repeats enough in your setup
that it causes soft lockups?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-08-26 11:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-26 7:27 [PATCH] mm: memcg: Fix memcg reclaim soft lockup Xunlei Pang
2020-08-26 8:11 ` Michal Hocko
2020-08-26 10:41 ` xunlei
2020-08-26 11:00 ` Michal Hocko [this message]
2020-08-26 11:45 ` xunlei
2020-08-26 11:54 ` Xunlei Pang
2020-08-26 12:00 ` xunlei
2020-08-26 12:07 ` Michal Hocko
2020-08-26 12:21 ` xunlei
2020-08-26 12:48 ` Michal Hocko
2020-08-26 13:16 ` xunlei
2020-08-26 13:26 ` Michal Hocko
2020-08-26 13:48 ` xunlei
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