Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262958AbUJ1K7L (ORCPT ); Thu, 28 Oct 2004 06:59:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262963AbUJ1K7L (ORCPT ); Thu, 28 Oct 2004 06:59:11 -0400 Received: from mxfep01.bredband.com ([195.54.107.70]:27579 "EHLO mxfep01.bredband.com") by vger.kernel.org with ESMTP id S262958AbUJ1K7G (ORCPT ); Thu, 28 Oct 2004 06:59:06 -0400 Subject: Re: Livelock with the shmctl04 test program from linux test project From: Alexander Nyberg To: Manfred Spraul Cc: linux-kernel@vger.kernel.org In-Reply-To: <41794334.1080206@colorfullife.com> References: <41794334.1080206@colorfullife.com> Content-Type: text/plain Message-Id: <1098961145.787.7.camel@boxen> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Thu, 28 Oct 2004 12:59:05 +0200 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3025 Lines: 48 > Hi Alexander, > > >I'm seeing some sort of livelock on my dual amd64 with the shmctl04 test program > > > What do you mean with "sort of livelock"? Does it recover after a few > minutes, does it recover if you send a signal to the shmctl04 test app? > What is the contents of /proc/sysvipc/shm while xfce4 is running/not > running? Sorry for late reply, but I just can't understand why & how this happens, been trying to grasp the IPC/SHM part but I'm missing something. One processor gets locked up and never released. I did: printk("taking lock\n"); spin_lock(&info->lock); printk("lock taken\n"); and it never prints out "lock taken" so i know where it locks up. Now the fun part, spinlock debugging doesn't catch it, but I did a simple patch to show who is holding a lock at the current time, and it appears noone has taken the lock. I really don't get this. With xfce4 running: key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime 0 32768 1600 393216 629 608 2 1000 1000 1000 1000 1098960009 0 1098960009 0 65537 1600 196608 644 608 2 1000 1000 1000 1000 1098960009 0 1098960009 0 98306 1600 393216 646 668 2 1000 1000 1000 1000 1098960014 1098960014 1098960009 0 131075 1600 393216 648 608 2 1000 1000 1000 1000 1098960021 0 1098960021 0 163844 1600 393216 666 700 2 1000 1000 1000 1000 1098960029 1098960029 1098960023 0 196613 1600 196608 666 700 2 1000 1000 1000 1000 1098960029 1098960029 1098960023 0 229382 1600 393216 643 608 2 1000 1000 1000 1000 1098960023 0 1098960023 0 262151 1600 393216 668 681 2 1000 1000 1000 1000 1098960025 1098960025 1098960025 0 294920 1600 196608 648 608 2 1000 1000 1000 1000 1098960026 0 1098960026 0 360457 1600 393216 706 711 2 1000 1000 1000 1000 1098960036 1098960036 1098960035 0 425994 1600 393216 715 716 2 1000 1000 1000 1000 1098960039 1098960084 1098960039 0 458763 1600 196608 715 608 2 1000 1000 1000 1000 1098960041 0 1098960041 0 491532 1600 393216 642 608 2 1000 1000 1000 1000 1098960059 0 1098960059 Console only: key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime - 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/