Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932601Ab3DSSxG (ORCPT ); Fri, 19 Apr 2013 14:53:06 -0400 Received: from mail-we0-f175.google.com ([74.125.82.175]:64946 "EHLO mail-we0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753543Ab3DSSxE (ORCPT ); Fri, 19 Apr 2013 14:53:04 -0400 MIME-Version: 1.0 Reply-To: sedat.dilek@gmail.com In-Reply-To: References: Date: Fri, 19 Apr 2013 20:53:00 +0200 Message-ID: Subject: Re: linux-next: Tree for Apr 18 [ call-trace: drm | x86 | smp | rcu related? ] From: Sedat Dilek To: Daniel Vetter Cc: Stephen Rothwell , linux-next , Linux Kernel Mailing List , x86@kernel.org, Ingo Molnar , Thomas Gleixner , Paul McKenney , Paul McKenney , DRI , Dave Airlie , Davidlohr Bueso , Linus Torvalds , Emmanuel Benisty , Rik van Riel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3706 Lines: 111 On Fri, Apr 19, 2013 at 6:43 PM, Sedat Dilek wrote: > On Fri, Apr 19, 2013 at 12:27 PM, Sedat Dilek wrote: >> On Fri, Apr 19, 2013 at 12:19 PM, Sedat Dilek wrote: >>> On Thu, Apr 18, 2013 at 11:59 PM, Sedat Dilek wrote: >>>> On Thu, Apr 18, 2013 at 9:48 PM, Daniel Vetter wrote: >>>>> On Thu, Apr 18, 2013 at 3:05 PM, Sedat Dilek wrote: >>>>>> On Thu, Apr 18, 2013 at 10:28 AM, Stephen Rothwell wrote: >>>>>>> Hi all, >>>>>>> >>>>>>> Changes since 20130417: >>>>>>> >>>>>>> New Trees: rpmsg (actually added yesterday) >>>>>>> ppc-temp (replacing powerpc for this week) >>>>>>> >>>>>>> The ceph tree gained a conflict against Linus' tree. >>>>>>> >>>>>>> The net-next tree gained a conflict against the infiniband tree. >>>>>>> >>>>>>> The usb tree gained a build failure so I used the version from >>>>>>> next-20130417. >>>>>>> >>>>>>> I added two merge fix patches after the gen-gpio tree. >>>>>>> >>>>>>> The ppc-temp tree gained a conflict against the metag tree. >>>>>>> >>>>>>> The akpm tree lost a patch that turned up elsewhere. >>>>>>> >>>>>>> ---------------------------------------------------------------------------- >>>>>>> >>>>>> >>>>>> Not sure what the root-cause for this call-trace is (see screenshot). >>>>>> >>>>>> This is reproducible when running my kernel build-script (4 parallel-make-jobs). >>>>>> >>>>>> Any hints welcome! >>>>> >>>>> The panic handlers in our modeset code are pretty decent fubar - they >>>>> take mutexes all over the place. So I think the backtrace you see >>>>> there is actually a secondary effect. I've looked into fixing this up, >>>>> but the issue is that drivers themselves have tons of state protected >>>>> with mutexes, which all potentially affects the panic handler. So I've >>>>> given up on that for now ... >>>> >>>> Thanks for taking care. >>>> >>>> On suspicion [1] I have reverted [2]... NOPE. >>>> >>>> - Sedat - >>>> >>>> [1] http://marc.info/?l=linux-kernel&m=136631921208895&w=2 >>>> [2] http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=5a90d1a95356de7a32acb2e5309ac579a891af8f >>>> >>> >>> Hmmm, the issue seems to be gone with today's Linux-Next (next-20130419). >>> My kernel-build is still running with no call-trace... >>> >> >> NO, It's no good. >> > > I tried to switch from SLUB to SLAB... > > ...and also from VIRT_CPU_ACCOUNTING_GEN to TICK_CPU_ACCOUNTING. > > 2x NOPE. > > In one kernel-build I saw in my console... > > semop(1): encountered an error: Identifier removed > > ...if this says sth. to you. > [ CC folks from below thread ] I have found a thread called "Re: ipc,sem: sysv semaphore scalability" on LKML with a screenshot that shows the same call-trace. I followed it a bit. There is a patch in [3]... unconfirmed. Comments on the rcu read-lock and "sem_lock()" vs "sem_unlock()" from Linus. What's the status of this discussion? - Sedat - [1] https://lkml.org/lkml/2013/3/30/6 [2] http://i.imgur.com/uk6gmq1.jpg [3] https://lkml.org/lkml/2013/3/31/12 [4] https://lkml.org/lkml/2013/3/31/77 > - Sedat - > > - Sedat - > >> - Sedat - >> >> [1] http://www.youtube.com/watch?v=LwicaralvS0 >> >>> - Sedat - >>> >>>>> -Daniel >>>>> -- >>>>> Daniel Vetter >>>>> Software Engineer, Intel Corporation >>>>> +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/