From: Dave Jones <davej@redhat.com>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: hrtimer deadlock caused by nohz_full
Date: Thu, 2 Oct 2014 14:24:09 -0400 [thread overview]
Message-ID: <20141002182409.GA29934@redhat.com> (raw)
In-Reply-To: <20140925234657.GB14870@lerouge>
On Fri, Sep 26, 2014 at 01:46:59AM +0200, Frederic Weisbecker wrote:
> > > [<ffffffffa10f95f8>] hrtimer_try_to_cancel+0x58/0x1f0
> > > [<ffffffffa10f97aa>] hrtimer_cancel+0x1a/0x30
> > > [<ffffffffa110a0e7>] tick_nohz_restart+0x17/0x90
> > > [<ffffffffa110af38>] __tick_nohz_full_check+0xc8/0xe0
> > > [<ffffffffa110af5e>] nohz_full_kick_work_func+0xe/0x10
> > > [<ffffffffa117c9bf>] irq_work_run_list+0x4f/0x70
> > > [<ffffffffa117ca0a>] irq_work_run+0x2a/0x60
> > > [<ffffffffa10f82eb>] update_process_times+0x5b/0x70
> > > [<ffffffffa1109dc5>] tick_sched_handle.isra.21+0x25/0x60
> > > [<ffffffffa110a0b1>] tick_sched_timer+0x41/0x60
> > > [<ffffffffa10f8c71>] __run_hrtimer+0x81/0x480
> > > [<ffffffffa110a070>] ? tick_sched_do_timer+0x90/0x90
> > > [<ffffffffa10f9b27>] hrtimer_interrupt+0x107/0x260
> > > [<ffffffffa10331a4>] local_apic_timer_interrupt+0x34/0x60
> > > [<ffffffffa182734f>] smp_apic_timer_interrupt+0x3f/0x60
> > > [<ffffffffa182576f>] apic_timer_interrupt+0x6f/0x80
> >
> > hrtimer_interrupt
> > tick_sched_timer
> > tick_sched_handle
> > update_process_times
> > irq_work_run
> > irq_work_run_list
> > nohz_full_kick_work_func
> > __tick_nohz_full_check
> > tick_nohz_restart
> > hrtimer_cancel
> >
> > And that hrtimer_cancel is:
> >
> > static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
> > {
> > hrtimer_cancel(&ts->sched_timer);
> >
> > Now, that's really bad because we are in the timer callback of
> > ts->sched_timer. So hrtimer_cancel will loop forever waiting for the
> > callback to complete.
> >
> > Frederic !?!?
>
> Right, this patchset fixes it: "[PATCH 0/8] nohz: Fix nohz kick irq work on tick v3"
>
> I was about to make the pull request, the branch is acked by peterz.
> Would you like to pull it? It's all merge window material.
>
> git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
> nohz/fixes-v3
I'm now hitting this with such regularity that it's preventing me from
tracking down other bugs. Can we get this merged soon please ?
Dave
next prev parent reply other threads:[~2014-10-02 18:24 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-25 14:14 watchdog kicked in while shrinking inactive list Dave Jones
2014-09-25 14:35 ` hrtimer deadlock caused by nohz_full Thomas Gleixner
2014-09-25 14:35 ` Thomas Gleixner
2014-09-25 23:46 ` Frederic Weisbecker
2014-09-25 23:46 ` Frederic Weisbecker
2014-10-02 18:24 ` Dave Jones [this message]
2014-10-02 22:01 ` Mike Lothian
2014-10-07 15:30 ` Frederic Weisbecker
2014-10-07 17:37 ` Dave Jones
2014-10-07 17:42 ` Thomas Gleixner
2014-10-09 2:02 ` Dave Jones
2014-10-09 3:30 ` Frederic Weisbecker
2014-10-09 3:49 ` Dave Jones
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