From: Thomas Gleixner <tglx@linutronix.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Yang Shi <yang.s@alibaba-inc.com>,
longman@redhat.com, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2 v3] lib: debugobjects: touch watchdog to avoid softlockup when !CONFIG_PREEMPT
Date: Thu, 18 Jan 2018 16:15:12 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1801181615010.1847@nanos> (raw)
In-Reply-To: <20180118150505.GD2249@hirez.programming.kicks-ass.net>
On Thu, 18 Jan 2018, Peter Zijlstra wrote:
> On Thu, Jan 18, 2018 at 10:02:25AM +0100, Thomas Gleixner wrote:
> > > > 2) We can do a cond_resched() if not in atomic context and interrupts are
> > > > enabled.
> > >
> > > I did try this before I went with touching softlockup watchdog approach. The
> > > problem is in_atomic() can't tell if it is in atomic context on non-preempt
> > > kernel. For preempt kernel, it is easy.
> >
> > Peter, can we do anything about that?
>
> Not really :/ Take for instance a spinlock on !PREEMPT, only the lock
> variable is touched, preempt_count isn't. So we cannot know.
Fair enough.
next prev parent reply other threads:[~2018-01-18 15:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-03 23:56 [PATCH 1/2 v3] lib: debugobjects: export max loops counter Yang Shi
2018-01-03 23:56 ` [PATCH 2/2 v3] lib: debugobjects: touch watchdog to avoid softlockup when !CONFIG_PREEMPT Yang Shi
2018-01-17 12:21 ` Thomas Gleixner
2018-01-18 1:41 ` Yang Shi
2018-01-18 9:02 ` Thomas Gleixner
2018-01-18 15:05 ` Peter Zijlstra
2018-01-18 15:15 ` Thomas Gleixner [this message]
2018-01-20 0:06 ` Yang Shi
-- strict thread matches above, loose matches on Subject: below --
2017-11-28 19:45 Yang Shi
2017-11-28 20:24 ` Waiman Long
2017-12-07 19:16 ` Yang Shi
2017-12-28 15:36 ` Thomas Gleixner
2018-01-03 23:54 ` Yang Shi
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