From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [tip:sched/core] sched/core: Add debugging code to catch missing update_rq_clock() calls Date: Fri, 3 Feb 2017 09:53:01 +0100 Message-ID: <20170203085301.GA6515@twins.programming.kicks-ass.net> References: <20160921133813.31976-8-matt@codeblueprint.co.uk> <87tw8gutp6.fsf@concordia.ellerman.id.au> <20170130213435.GM31613@codeblueprint.co.uk> <33118425-8548-475A-8DED-9A2424C0BCCC@linux.vnet.ibm.com> <1485863317.4498.2.camel@gmx.de> <20170202155506.GX6515@twins.programming.kicks-ass.net> <3BAB5673-2BF8-46E0-8018-6A0F3DEEC9F7@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <3BAB5673-2BF8-46E0-8018-6A0F3DEEC9F7@linux.vnet.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" To: Sachin Sant Cc: Matt Fleming , Mike Galbraith , "linuxppc-dev@lists.ozlabs.org" , LKML , "linux-next@vger.kernel.org" , Ross Zwisler List-Id: linux-next.vger.kernel.org On Fri, Feb 03, 2017 at 10:03:14AM +0530, Sachin Sant wrote: > > > On 02-Feb-2017, at 9:25 PM, Peter Zijlstra wrote: > > > > On Tue, Jan 31, 2017 at 10:22:47AM -0700, Ross Zwisler wrote: > >> On Tue, Jan 31, 2017 at 4:48 AM, Mike Galbraith wrote: > >>> On Tue, 2017-01-31 at 16:30 +0530, Sachin Sant wrote: > > > > > > Could some of you test this? It seems to cure things in my (very) > > limited testing. > > > > I ran few cycles of cpu hot(un)plug tests. In most cases it works except one > where I ran into rcu stall: > > [ 173.493453] INFO: rcu_sched detected stalls on CPUs/tasks: > [ 173.493473] 8-...: (2 GPs behind) idle=006/140000000000000/0 softirq=0/0 fqs=2996 > [ 173.493476] (detected by 0, t=6002 jiffies, g=885, c=884, q=6350) Right, I actually saw that too, but I don't think that would be related to my patch. I'll see if I can dig into this though, ought to get fixed regardless. Thanks for testing!