From: Peter Zijlstra <peterz@infradead.org>
To: Joe Perches <joe@perches.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>,
linux-kernel@vger.kernel.org, pmladek@suse.com,
sergey.senozhatsky@gmail.com, rostedt@goodmis.org,
mingo@redhat.com, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
bsegall@google.com, mgorman@suse.de, songmuchun@bytedance.com
Subject: Re: [PATCH 2/2] sched: mark PRINTK_DEFERRED_CONTEXT_MASK in __schedule()
Date: Mon, 28 Sep 2020 10:00:22 +0200 [thread overview]
Message-ID: <20200928080022.GD2611@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <0e8e87e25c90339fe790252626855cbb47bc2c08.camel@perches.com>
On Mon, Sep 28, 2020 at 12:52:44AM -0700, Joe Perches wrote:
> On Mon, 2020-09-28 at 09:32 +0200, Peter Zijlstra wrote:
> > On Mon, Sep 28, 2020 at 12:11:30AM +0800, Chengming Zhou wrote:
> > > The WARN_ON/WARN_ON_ONCE with rq lock held in __schedule() should be
> > > deferred by marking the PRINTK_DEFERRED_CONTEXT_MASK, or will cause
> > > deadlock on rq lock in the printk path.
> []
> > NAK printk_deferred is an abomination, kill that.
>
> Didn't you introduce it?
> Should you be complaining to yourself?
Yeah. I should've hacked around it then I suppose. Still, no reason to
proliferate that crap. Afaik the new printk should be able to deal with
this at some point.
The thing we're not going to do it add a cache-miss to schedule just
because.
next prev parent reply other threads:[~2020-09-28 8:00 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-27 16:11 [PATCH 1/2] printk: Add printk_deferred_{enter, exit} Chengming Zhou
2020-09-27 16:11 ` [PATCH 2/2] sched: mark PRINTK_DEFERRED_CONTEXT_MASK in __schedule() Chengming Zhou
2020-09-28 7:32 ` Peter Zijlstra
2020-09-28 7:52 ` Joe Perches
2020-09-28 8:00 ` Peter Zijlstra [this message]
2020-09-28 8:06 ` Peter Zijlstra
2020-09-28 8:54 ` [External] " Chengming Zhou
2020-09-28 9:01 ` Peter Zijlstra
2020-09-28 10:04 ` Chengming Zhou
2020-09-28 10:25 ` Peter Zijlstra
2020-09-28 23:50 ` Sergey Senozhatsky
2020-09-29 14:27 ` Petr Mladek
2020-09-29 15:09 ` Peter Zijlstra
2020-09-30 0:48 ` Sergey Senozhatsky
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