From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Petr Mladek <pmladek@suse.com>,
akpm@linux-foundation.org, linux-mm@kvack.org,
Cong Wang <xiyou.wangcong@gmail.com>,
Dave Hansen <dave.hansen@intel.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@kernel.org>,
Vlastimil Babka <vbabka@suse.cz>,
Peter Zijlstra <peterz@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Jan Kara <jack@suse.cz>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
rostedt@rostedt.homelinux.com,
Byungchul Park <byungchul.park@lge.com>,
Pavel Machek <pavel@ucw.cz>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
Date: Mon, 23 Apr 2018 14:35:31 +0900 [thread overview]
Message-ID: <20180423053531.GB3643@jagdpanzerIV> (raw)
In-Reply-To: <20180123154347.GE1771050@devbig577.frc2.facebook.com>
On (01/23/18 07:43), Tejun Heo wrote:
> >
> > We can have more. But if printk is causing printks, that's a major bug.
> > And work queues are not going to fix it, it will just spread out the
> > pain. Have it be 100 printks, it needs to be fixed if it is happening.
> > And having all printks just generate more printks is not helpful. Even
> > if we slow them down. They will still never end.
>
> So, at least in the case that we were seeing, it isn't that black and
> white. printk keeps causing printks but only because printk buffer
> flushing is preventing the printk'ing context from making forward
> progress. The key problem there is that a flushing context may get
> pinned flushing indefinitely and using a separate context does solve
> the problem.
Hello Tejun,
I'm willing to take a look at those printk()-s from console drivers.
Any chance you can send me some of the backtraces you see [the most
common/disturbing]?
-ss
WARNING: multiple messages have this Message-ID (diff)
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Petr Mladek <pmladek@suse.com>,
akpm@linux-foundation.org, linux-mm@kvack.org,
Cong Wang <xiyou.wangcong@gmail.com>,
Dave Hansen <dave.hansen@intel.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@kernel.org>,
Vlastimil Babka <vbabka@suse.cz>,
Peter Zijlstra <peterz@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Jan Kara <jack@suse.cz>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
rostedt@home.goodmis.org, Byungchul Park <byungchul.park@lge.com>,
Pavel Machek <pavel@ucw.cz>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 0/2] printk: Console owner and waiter logic cleanup
Date: Mon, 23 Apr 2018 14:35:31 +0900 [thread overview]
Message-ID: <20180423053531.GB3643@jagdpanzerIV> (raw)
In-Reply-To: <20180123154347.GE1771050@devbig577.frc2.facebook.com>
On (01/23/18 07:43), Tejun Heo wrote:
> >
> > We can have more. But if printk is causing printks, that's a major bug.
> > And work queues are not going to fix it, it will just spread out the
> > pain. Have it be 100 printks, it needs to be fixed if it is happening.
> > And having all printks just generate more printks is not helpful. Even
> > if we slow them down. They will still never end.
>
> So, at least in the case that we were seeing, it isn't that black and
> white. printk keeps causing printks but only because printk buffer
> flushing is preventing the printk'ing context from making forward
> progress. The key problem there is that a flushing context may get
> pinned flushing indefinitely and using a separate context does solve
> the problem.
Hello Tejun,
I'm willing to take a look at those printk()-s from console drivers.
Any chance you can send me some of the backtraces you see [the most
common/disturbing]?
-ss
next prev parent reply other threads:[~2018-04-23 5:35 UTC|newest]
Thread overview: 280+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-10 13:24 [PATCH v5 0/2] printk: Console owner and waiter logic cleanup Petr Mladek
2018-01-10 13:24 ` Petr Mladek
2018-01-10 13:24 ` [PATCH v5 1/2] printk: Add console owner and waiter logic to load balance console writes Petr Mladek
2018-01-10 13:24 ` Petr Mladek
2018-01-10 16:50 ` Steven Rostedt
2018-01-10 16:50 ` Steven Rostedt
2018-01-12 16:54 ` Steven Rostedt
2018-01-12 16:54 ` Steven Rostedt
2018-01-12 17:11 ` Steven Rostedt
2018-01-12 17:11 ` Steven Rostedt
2018-01-17 19:13 ` Rasmus Villemoes
2018-01-17 19:13 ` Rasmus Villemoes
2018-01-17 19:33 ` Steven Rostedt
2018-01-17 19:33 ` Steven Rostedt
2018-01-19 9:51 ` Sergey Senozhatsky
2018-01-19 9:51 ` Sergey Senozhatsky
2018-01-18 22:03 ` Pavel Machek
2018-01-18 22:03 ` Pavel Machek
2018-01-19 0:20 ` Steven Rostedt
2018-01-19 0:20 ` Steven Rostedt
2018-01-17 2:19 ` Byungchul Park
2018-01-17 2:19 ` Byungchul Park
2018-01-17 4:54 ` Byungchul Park
2018-01-17 4:54 ` Byungchul Park
2018-01-17 7:34 ` Byungchul Park
2018-01-17 7:34 ` Byungchul Park
2018-01-17 12:04 ` Petr Mladek
2018-01-17 12:04 ` Petr Mladek
2018-01-18 1:53 ` Byungchul Park
2018-01-18 1:53 ` Byungchul Park
2018-01-18 1:57 ` Byungchul Park
2018-01-18 1:57 ` Byungchul Park
2018-01-18 2:19 ` Steven Rostedt
2018-01-18 2:19 ` Steven Rostedt
2018-01-18 4:01 ` Byungchul Park
2018-01-18 4:01 ` Byungchul Park
2018-01-18 15:21 ` Steven Rostedt
2018-01-18 15:21 ` Steven Rostedt
2018-01-19 2:37 ` Byungchul Park
2018-01-19 2:37 ` Byungchul Park
2018-01-19 3:27 ` Steven Rostedt
2018-01-19 3:27 ` Steven Rostedt
2018-01-22 2:31 ` Byungchul Park
2018-01-22 2:31 ` Byungchul Park
2018-01-10 13:24 ` [PATCH v5 2/2] printk: Hide console waiter logic into helpers Petr Mladek
2018-01-10 13:24 ` Petr Mladek
2018-01-10 17:52 ` Steven Rostedt
2018-01-10 17:52 ` Steven Rostedt
2018-01-11 12:03 ` Petr Mladek
2018-01-11 12:03 ` Petr Mladek
2018-01-12 15:37 ` Steven Rostedt
2018-01-12 15:37 ` Steven Rostedt
2018-01-12 16:08 ` Petr Mladek
2018-01-12 16:08 ` Petr Mladek
2018-01-12 16:36 ` Steven Rostedt
2018-01-12 16:36 ` Steven Rostedt
2018-01-15 16:08 ` Petr Mladek
2018-01-15 16:08 ` Petr Mladek
2018-01-16 5:05 ` Sergey Senozhatsky
2018-01-16 5:05 ` Sergey Senozhatsky
2018-01-10 14:05 ` [PATCH v5 0/2] printk: Console owner and waiter logic cleanup Tejun Heo
2018-01-10 14:05 ` Tejun Heo
2018-01-10 16:29 ` Petr Mladek
2018-01-10 16:29 ` Petr Mladek
2018-01-10 17:02 ` Tejun Heo
2018-01-10 17:02 ` Tejun Heo
2018-01-10 18:21 ` Peter Zijlstra
2018-01-10 18:21 ` Peter Zijlstra
2018-01-10 18:30 ` Tejun Heo
2018-01-10 18:30 ` Tejun Heo
2018-01-10 18:41 ` Peter Zijlstra
2018-01-10 18:41 ` Peter Zijlstra
2018-01-10 19:05 ` Tejun Heo
2018-01-10 19:05 ` Tejun Heo
2018-01-11 5:15 ` Sergey Senozhatsky
2018-01-11 5:15 ` Sergey Senozhatsky
2018-01-10 18:22 ` Steven Rostedt
2018-01-10 18:22 ` Steven Rostedt
2018-01-10 18:36 ` Tejun Heo
2018-01-10 18:36 ` Tejun Heo
2018-01-10 18:40 ` Mathieu Desnoyers
2018-01-10 18:40 ` Mathieu Desnoyers
2018-01-11 7:36 ` Sergey Senozhatsky
2018-01-11 7:36 ` Sergey Senozhatsky
2018-01-11 11:24 ` Petr Mladek
2018-01-11 11:24 ` Petr Mladek
2018-01-11 13:19 ` Sergey Senozhatsky
2018-01-11 13:19 ` Sergey Senozhatsky
2018-01-24 9:36 ` Peter Zijlstra
2018-01-24 9:36 ` Peter Zijlstra
2018-01-24 18:46 ` Tejun Heo
2018-01-24 18:46 ` Tejun Heo
2018-05-09 8:58 ` Sergey Senozhatsky
2018-05-09 8:58 ` Sergey Senozhatsky
2018-01-10 18:54 ` Steven Rostedt
2018-01-10 18:54 ` Steven Rostedt
2018-01-11 5:10 ` Sergey Senozhatsky
2018-01-11 5:10 ` Sergey Senozhatsky
2018-01-10 18:05 ` Steven Rostedt
2018-01-10 18:05 ` Steven Rostedt
2018-01-10 18:12 ` Tejun Heo
2018-01-10 18:12 ` Tejun Heo
2018-01-10 18:14 ` Tejun Heo
2018-01-10 18:14 ` Tejun Heo
2018-01-10 18:45 ` Steven Rostedt
2018-01-10 18:45 ` Steven Rostedt
2018-01-10 18:41 ` Steven Rostedt
2018-01-10 18:41 ` Steven Rostedt
2018-01-10 18:57 ` Tejun Heo
2018-01-10 18:57 ` Tejun Heo
2018-01-10 19:17 ` Steven Rostedt
2018-01-10 19:17 ` Steven Rostedt
2018-01-10 19:34 ` Tejun Heo
2018-01-10 19:34 ` Tejun Heo
2018-01-10 19:44 ` Steven Rostedt
2018-01-10 19:44 ` Steven Rostedt
2018-01-10 22:44 ` Tejun Heo
2018-01-10 22:44 ` Tejun Heo
2018-01-11 5:35 ` Sergey Senozhatsky
2018-01-11 5:35 ` Sergey Senozhatsky
2018-01-11 4:58 ` Sergey Senozhatsky
2018-01-11 4:58 ` Sergey Senozhatsky
2018-01-11 9:34 ` Petr Mladek
2018-01-11 9:34 ` Petr Mladek
2018-01-11 10:38 ` Sergey Senozhatsky
2018-01-11 10:38 ` Sergey Senozhatsky
2018-01-11 11:50 ` Petr Mladek
2018-01-11 11:50 ` Petr Mladek
2018-01-11 16:29 ` Steven Rostedt
2018-01-11 16:29 ` Steven Rostedt
2018-01-12 1:30 ` Steven Rostedt
2018-01-12 1:30 ` Steven Rostedt
2018-01-12 2:55 ` Steven Rostedt
2018-01-12 2:55 ` Steven Rostedt
2018-01-12 4:20 ` Steven Rostedt
2018-01-12 4:20 ` Steven Rostedt
2018-01-16 19:44 ` Tejun Heo
2018-01-16 19:44 ` Tejun Heo
2018-01-17 9:12 ` Petr Mladek
2018-01-17 9:12 ` Petr Mladek
2018-01-17 15:15 ` Tejun Heo
2018-01-17 15:15 ` Tejun Heo
2018-01-17 17:12 ` Steven Rostedt
2018-01-17 17:12 ` Steven Rostedt
2018-01-17 18:42 ` Steven Rostedt
2018-01-17 18:42 ` Steven Rostedt
2018-01-19 18:20 ` Steven Rostedt
2018-01-19 18:20 ` Steven Rostedt
2018-01-20 7:14 ` Sergey Senozhatsky
2018-01-20 7:14 ` Sergey Senozhatsky
2018-01-20 15:49 ` Steven Rostedt
2018-01-20 15:49 ` Steven Rostedt
2018-01-21 14:15 ` Sergey Senozhatsky
2018-01-21 14:15 ` Sergey Senozhatsky
2018-01-21 21:04 ` Steven Rostedt
2018-01-21 21:04 ` Steven Rostedt
2018-01-22 8:56 ` Sergey Senozhatsky
2018-01-22 8:56 ` Sergey Senozhatsky
2018-01-22 10:28 ` Sergey Senozhatsky
2018-01-22 10:28 ` Sergey Senozhatsky
2018-01-22 10:36 ` Sergey Senozhatsky
2018-01-22 10:36 ` Sergey Senozhatsky
2018-01-23 6:40 ` Sergey Senozhatsky
2018-01-23 6:40 ` Sergey Senozhatsky
2018-01-23 7:05 ` Sergey Senozhatsky
2018-01-23 7:05 ` Sergey Senozhatsky
2018-01-23 7:31 ` Sergey Senozhatsky
2018-01-23 7:31 ` Sergey Senozhatsky
2018-01-23 14:56 ` Steven Rostedt
2018-01-23 14:56 ` Steven Rostedt
2018-01-23 15:21 ` Sergey Senozhatsky
2018-01-23 15:21 ` Sergey Senozhatsky
2018-01-23 15:41 ` Steven Rostedt
2018-01-23 15:41 ` Steven Rostedt
2018-01-23 15:43 ` Tejun Heo
2018-01-23 15:43 ` Tejun Heo
2018-01-23 16:12 ` Sergey Senozhatsky
2018-01-23 16:12 ` Sergey Senozhatsky
2018-01-23 16:13 ` Steven Rostedt
2018-01-23 16:13 ` Steven Rostedt
2018-01-23 17:21 ` Tejun Heo
2018-01-23 17:21 ` Tejun Heo
2018-04-23 5:35 ` Sergey Senozhatsky [this message]
2018-04-23 5:35 ` Sergey Senozhatsky
2018-01-23 16:01 ` Sergey Senozhatsky
2018-01-23 16:01 ` Sergey Senozhatsky
2018-01-23 16:24 ` Steven Rostedt
2018-01-23 16:24 ` Steven Rostedt
2018-01-24 2:11 ` Sergey Senozhatsky
2018-01-24 2:11 ` Sergey Senozhatsky
2018-01-24 2:52 ` Steven Rostedt
2018-01-24 2:52 ` Steven Rostedt
2018-01-24 4:44 ` Sergey Senozhatsky
2018-01-24 4:44 ` Sergey Senozhatsky
2018-01-23 17:22 ` Tejun Heo
2018-01-23 17:22 ` Tejun Heo
2018-01-20 12:19 ` Tejun Heo
2018-01-20 12:19 ` Tejun Heo
2018-01-20 14:51 ` Steven Rostedt
2018-01-20 14:51 ` Steven Rostedt
2018-01-17 20:05 ` Tejun Heo
2018-01-17 20:05 ` Tejun Heo
2018-01-18 5:43 ` Sergey Senozhatsky
2018-01-18 5:43 ` Sergey Senozhatsky
2018-01-18 11:51 ` Petr Mladek
2018-01-18 11:51 ` Petr Mladek
2018-01-18 5:42 ` Sergey Senozhatsky
2018-01-18 5:42 ` Sergey Senozhatsky
2018-01-12 3:12 ` Sergey Senozhatsky
2018-01-12 3:12 ` Sergey Senozhatsky
2018-01-12 2:56 ` Sergey Senozhatsky
2018-01-12 2:56 ` Sergey Senozhatsky
2018-01-12 3:21 ` Steven Rostedt
2018-01-12 3:21 ` Steven Rostedt
2018-01-12 10:05 ` Sergey Senozhatsky
2018-01-12 10:05 ` Sergey Senozhatsky
2018-01-12 12:21 ` Steven Rostedt
2018-01-12 12:21 ` Steven Rostedt
2018-01-12 12:55 ` Petr Mladek
2018-01-12 12:55 ` Petr Mladek
2018-01-13 7:31 ` Sergey Senozhatsky
2018-01-13 7:31 ` Sergey Senozhatsky
2018-01-15 8:51 ` Petr Mladek
2018-01-15 8:51 ` Petr Mladek
2018-01-15 9:48 ` Sergey Senozhatsky
2018-01-15 9:48 ` Sergey Senozhatsky
2018-01-16 5:16 ` Sergey Senozhatsky
2018-01-16 5:16 ` Sergey Senozhatsky
2018-01-16 9:08 ` Petr Mladek
2018-01-16 9:08 ` Petr Mladek
2018-01-15 12:08 ` Steven Rostedt
2018-01-15 12:08 ` Steven Rostedt
2018-01-16 4:51 ` Sergey Senozhatsky
2018-01-16 4:51 ` Sergey Senozhatsky
2018-01-13 7:28 ` Sergey Senozhatsky
2018-01-13 7:28 ` Sergey Senozhatsky
2018-01-15 10:17 ` Petr Mladek
2018-01-15 10:17 ` Petr Mladek
2018-01-15 11:50 ` Petr Mladek
2018-01-15 11:50 ` Petr Mladek
2018-01-16 6:10 ` Sergey Senozhatsky
2018-01-16 6:10 ` Sergey Senozhatsky
2018-01-16 9:36 ` Petr Mladek
2018-01-16 9:36 ` Petr Mladek
2018-01-16 10:10 ` Sergey Senozhatsky
2018-01-16 10:10 ` Sergey Senozhatsky
2018-01-16 16:06 ` Steven Rostedt
2018-01-16 16:06 ` Steven Rostedt
2018-01-16 5:23 ` Sergey Senozhatsky
2018-01-16 5:23 ` Sergey Senozhatsky
2018-01-15 12:06 ` Steven Rostedt
2018-01-15 12:06 ` Steven Rostedt
2018-01-15 14:45 ` Petr Mladek
2018-01-15 14:45 ` Petr Mladek
2018-01-16 2:23 ` Sergey Senozhatsky
2018-01-16 2:23 ` Sergey Senozhatsky
2018-01-16 4:47 ` Sergey Senozhatsky
2018-01-16 4:47 ` Sergey Senozhatsky
2018-01-16 10:19 ` Petr Mladek
2018-01-16 10:19 ` Petr Mladek
2018-01-17 2:24 ` Sergey Senozhatsky
2018-01-17 2:24 ` Sergey Senozhatsky
2018-01-16 15:45 ` Steven Rostedt
2018-01-16 15:45 ` Steven Rostedt
2018-01-17 2:18 ` Sergey Senozhatsky
2018-01-17 2:18 ` Sergey Senozhatsky
2018-01-17 13:04 ` Petr Mladek
2018-01-17 13:04 ` Petr Mladek
2018-01-17 15:24 ` Steven Rostedt
2018-01-17 15:24 ` Steven Rostedt
2018-01-18 4:31 ` Sergey Senozhatsky
2018-01-18 4:31 ` Sergey Senozhatsky
2018-01-18 15:22 ` Steven Rostedt
2018-01-18 15:22 ` Steven Rostedt
2018-01-16 10:13 ` Petr Mladek
2018-01-16 10:13 ` Petr Mladek
2018-01-17 6:29 ` Sergey Senozhatsky
2018-01-17 6:29 ` Sergey Senozhatsky
2018-01-16 1:46 ` Sergey Senozhatsky
2018-01-16 1:46 ` Sergey Senozhatsky
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