From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [tip:timers/urgent] timekeeping: Fix HRTICK related deadlock from ntp lock changes Date: Tue, 17 Sep 2013 09:07:28 +0200 Message-ID: <20130917070728.GC20661@gmail.com> References: <1378943457-27314-1-git-send-email-john.stultz@linaro.org> <20130916160426.GA24669@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130916160426.GA24669@Krystal> Sender: linux-kernel-owner@vger.kernel.org To: Mathieu Desnoyers Cc: hpa@zytor.com, linux-kernel@vger.kernel.org, gerlando.falauto@keymile.com, john.stultz@linaro.org, minggr@gmail.com, tglx@linutronix.de, linux-tip-commits@vger.kernel.org, lttng-dev@lists.lttng.org List-Id: lttng-dev@lists.lttng.org * Mathieu Desnoyers wrote: > Hi Ingo, > > Do you have an estimate of the time it will take for this fix to hit > mainline, stable-3.10 and stable-3.11 ? Meanwhile, I'm marking 3.10 and > 3.11 as broken for LTTng with a kernel version at compile-time, since > this kernel regression currently triggers hard system lockup when people > use LTTng on those kernels, and this is certainly something nobody > wants. So, at least as per the description of John, this should only trigger if SCHED_HRTICK is enabled in sched_features - which is disabled by default, it's a debug-only development feature. Does the bug trigger on more regular kernels as well? I planned to send it Linus after v3.12-rc1, in the next day or two. Thanks, Ingo