From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: lockdep splat in CPU hotplug Date: Wed, 22 Oct 2014 16:28:14 +0200 Message-ID: <5447BEFE.2040806@linaro.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Jiri Kosina , Peter Zijlstra , Ingo Molnar , "Rafael J. Wysocki" , Pavel Machek , Steven Rostedt , Dave Jones , "Paul E. McKenney" , Nicolas Pitre Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org On 10/22/2014 11:53 AM, Jiri Kosina wrote: > On Tue, 21 Oct 2014, Jiri Kosina wrote: > >> Hi, >> >> I am seeing the lockdep report below when resuming from suspend-to-d= isk >> with current Linus' tree (c2661b80609). >> >> The reason for CCing Ingo and Peter is that I can't make any sense o= f one >> of the stacktraces lockdep is providing. >> >> Please have a look at the very first stacktrace in the dump, where l= ockdep >> is trying to explain where cpu_hotplug.lock#2 has been acquired. It = seems >> to imply that cpuidle_pause() is taking cpu_hotplug.lock, but that's= not >> the case at all. >> >> What am I missing? > > Okay, reverting 442bf3aaf55a ("sched: Let the scheduler see CPU idle > states") and followup 83a0a96a5f26 ("sched/fair: Leverage the idle st= ate > info when choosing the "idlest" cpu") which depends on it makes the s= plat > go away. Are you able to reproduce it by offlining the cpu and onlining it again= ? --=20 Linaro.org =E2=94=82 Open source software fo= r ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog