From: Peter Zijlstra <peterz@infradead.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Guenter Roeck <linux@roeck-us.net>,
linux-kernel@vger.kernel.org, Don Zickus <dzickus@redhat.com>,
Ingo Molnar <mingo@kernel.org>
Subject: Re: Crashes in perf_event_ctx_lock_nested
Date: Wed, 1 Nov 2017 09:14:50 +0100 [thread overview]
Message-ID: <20171101081450.waqzz2ftebaw3tal@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <alpine.DEB.2.20.1710312145190.1942@nanos>
On Tue, Oct 31, 2017 at 10:32:00PM +0100, Thomas Gleixner wrote:
> That means we can have the following situation:
>
> lock(watchdog_mutex);
> lockup_detector_reconfigure();
> cpus_read_lock();
> stop();
> park()
> update();
> start();
> unpark()
> cpus_read_unlock(); thread runs()
> cleanup();
> unlock(watchdog_mutex);
>
Isn't there also a where hardlockup_detector_perf_init() creates an
event to 'probe' stuff, and then hardlockup_detector_perf_enable()
_again_ creates the event?
next prev parent reply other threads:[~2017-11-01 8:14 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-30 22:45 Crashes in perf_event_ctx_lock_nested Guenter Roeck
2017-10-31 13:48 ` Peter Zijlstra
2017-10-31 17:16 ` Guenter Roeck
2017-10-31 18:50 ` Don Zickus
2017-10-31 20:12 ` Guenter Roeck
2017-10-31 20:23 ` Don Zickus
2017-10-31 21:32 ` Thomas Gleixner
2017-10-31 22:11 ` Guenter Roeck
2017-11-01 18:11 ` Don Zickus
2017-11-01 18:34 ` Guenter Roeck
2017-11-01 19:46 ` [tip:core/urgent] watchdog/hardlockup/perf: Use atomics to track in-use cpu counter tip-bot for Don Zickus
2017-11-01 20:28 ` tip-bot for Don Zickus
2017-11-01 18:22 ` Crashes in perf_event_ctx_lock_nested Thomas Gleixner
2017-11-01 8:14 ` Peter Zijlstra [this message]
2017-11-01 8:26 ` Thomas Gleixner
2017-11-01 19:46 ` [tip:core/urgent] watchdog/harclockup/perf: Revert a33d44843d45 ("watchdog/hardlockup/perf: Simplify deferred event destroy") tip-bot for Thomas Gleixner
2017-11-01 20:32 ` Guenter Roeck
2017-11-01 20:52 ` Thomas Gleixner
2017-11-01 20:27 ` tip-bot for Thomas Gleixner
2017-10-31 18:48 ` Crashes in perf_event_ctx_lock_nested Don Zickus
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