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From: Michal Hocko <mhocko@kernel.org>
To: Boris Zhmurov <bb@kernelpanic.ru>
Cc: paulmck@linux.vnet.ibm.com, Paul Menzel <pmenzel@molgen.mpg.de>,
	Donald Buczek <buczek@molgen.mpg.de>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: INFO: rcu_sched detected stalls on CPUs/tasks with `kswapd` and `mem_cgroup_shrink_node`
Date: Fri, 2 Dec 2016 10:37:35 +0100	[thread overview]
Message-ID: <20161202093734.GE6830@dhcp22.suse.cz> (raw)
In-Reply-To: <e50dcb85-4552-9249-c53e-017fefcaf80b@kernelpanic.ru>

On Thu 01-12-16 21:10:01, Boris Zhmurov wrote:
> Michal Hocko 30/11/16 21:25:
> 
> >>> Do I get it right that s@cond_resched_rcu_qs@cond_resched@ didn't help?
> >>
> >> I didn't try that. I've tried 4 patches from Paul's linux-rcu tree.
> >> I can try another portion of patches, no problem :)
> > 
> > Replacing cond_resched_rcu_qs in shrink_node_memcg by cond_resched would
> > be really helpful to tell whether we are missing a real scheduling point
> > or whether something more serious is going on here.
> 
> Well, I can confirm, that replacing cond_resched_rcu_qs in
> shrink_node_memcg by cond_resched also makes dmesg clean from RCU CPU
> stall warnings.
> 
> I've attached patch (just modification of Paul's patch), that fixes RCU
> stall messages in situations, when all memory is used by
> couchbase/memcached + fs cache and linux starts to use swap.

OK, thanks for the confirmation! I will send a patch because it is true
that we do not have any scheduling point if no pages can be isolated
fromm the LRU. This might be what you are seeing.
-- 
Michal Hocko
SUSE Labs

  parent reply	other threads:[~2016-12-02  9:37 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20161125212000.GI31360@linux.vnet.ibm.com>
     [not found] ` <20161128095825.GI14788@dhcp22.suse.cz>
     [not found]   ` <20161128105425.GY31360@linux.vnet.ibm.com>
     [not found]     ` <3a4242cb-0198-0a3b-97ae-536fb5ff83ec@kernelpanic.ru>
     [not found]       ` <20161128143435.GC3924@linux.vnet.ibm.com>
     [not found]         ` <eba1571e-f7a8-09b3-5516-c2bc35b38a83@kernelpanic.ru>
     [not found]           ` <20161128150509.GG3924@linux.vnet.ibm.com>
     [not found]             ` <66fd50e1-a922-846a-f427-7654795bd4b5@kernelpanic.ru>
     [not found]               ` <20161130174802.GM18432@dhcp22.suse.cz>
     [not found]                 ` <fd34243c-2ebf-c14b-55e6-684a9dc614e7@kernelpanic.ru>
     [not found]                   ` <20161130182552.GN18432@dhcp22.suse.cz>
2016-12-01 18:10                     ` INFO: rcu_sched detected stalls on CPUs/tasks with `kswapd` and `mem_cgroup_shrink_node` Boris Zhmurov
2016-12-01 19:39                       ` Paul E. McKenney
2016-12-02  9:37                       ` Michal Hocko [this message]
2016-12-02 13:52                         ` Paul E. McKenney
2016-12-02 16:39                       ` Boris Zhmurov
2016-12-02 16:44                         ` Paul E. McKenney
2016-12-02 17:02                           ` Michal Hocko
2016-12-02 17:15                             ` Paul E. McKenney
     [not found] <24c226a5-1a4a-173e-8b4e-5107a2baac04@molgen.mpg.de>
2016-11-08 12:22 ` Paul Menzel
2016-11-08 17:03   ` Paul E. McKenney
2016-11-08 17:38     ` Paul Menzel
2016-11-08 18:39       ` Paul E. McKenney
2016-11-16 17:01         ` Paul Menzel
2016-11-16 17:30           ` Paul E. McKenney
2016-11-21 13:41             ` Michal Hocko
2016-11-21 14:01               ` Paul E. McKenney
2016-11-21 14:18                 ` Michal Hocko
2016-11-21 14:29                   ` Paul E. McKenney
2016-11-21 15:35                     ` Donald Buczek
2016-11-24 10:15                       ` Michal Hocko
2016-11-24 18:50                         ` Donald Buczek
2016-11-27  9:37                           ` Paul Menzel
2016-11-27  5:32                         ` Christopher S. Aker
2016-11-27  9:19                         ` Donald Buczek
2016-11-28 11:04                           ` Michal Hocko
2016-11-28 12:26                             ` Paul Menzel
2016-11-30 10:28                               ` Donald Buczek
2016-11-30 11:09                                 ` Michal Hocko
2016-11-30 11:43                                   ` Donald Buczek
2016-12-02  9:14                                     ` Donald Buczek
2016-12-06  8:32                                       ` Donald Buczek
2016-11-30 11:53                                   ` Paul E. McKenney
2016-11-30 11:54                                     ` Paul E. McKenney
2016-11-30 12:31                                       ` Paul Menzel
2016-11-30 14:31                                         ` Paul E. McKenney
2016-11-30 13:19                                     ` Michal Hocko
2016-11-30 14:29                                       ` Paul E. McKenney
2016-11-30 16:38                                         ` Peter Zijlstra
2016-11-30 17:02                                           ` Paul E. McKenney
2016-11-30 17:05                                           ` Michal Hocko
2016-11-30 17:23                                             ` Paul E. McKenney
2016-11-30 17:34                                               ` Michal Hocko
2016-11-30 17:50                                             ` Peter Zijlstra
2016-11-30 19:40                                               ` Paul E. McKenney
2016-12-01  5:30                                                 ` Peter Zijlstra
2016-12-01 12:40                                                   ` Paul E. McKenney
2016-12-01 16:36                                                     ` Peter Zijlstra
2016-12-01 16:59                                                       ` Paul E. McKenney
2016-12-01 18:09                                                         ` Peter Zijlstra
2016-12-01 18:42                                                           ` Paul E. McKenney
2016-12-01 18:49                                                             ` Peter Zijlstra

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