From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030698AbXCHV46 (ORCPT ); Thu, 8 Mar 2007 16:56:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030714AbXCHV46 (ORCPT ); Thu, 8 Mar 2007 16:56:58 -0500 Received: from mail03.syd.optusnet.com.au ([211.29.132.184]:50940 "EHLO mail03.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030698AbXCHV44 (ORCPT ); Thu, 8 Mar 2007 16:56:56 -0500 From: Con Kolivas To: Andrew Morton Subject: 2.6.21-rc3: /proc broken Date: Fri, 9 Mar 2007 08:56:44 +1100 User-Agent: KMail/1.9.5 Cc: linux-kernel@vger.kernel.org References: <20070307201915.4d579113.akpm@linux-foundation.org> <200703090152.49253.kernel@kolivas.org> In-Reply-To: <200703090152.49253.kernel@kolivas.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703090856.45386.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 09 March 2007 01:52, Con Kolivas wrote: > On Thursday 08 March 2007 15:19, Andrew Morton wrote: > > ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc3/ > >2. 6.21-rc3-mm2/ > > > > - This is the same as 2.6.21-rc3-mm1, except Con's CPU scheduler changes > > were dropped. > So on qemu I can reproduce the oops you're getting with your config (make > oldconfig all default on top of your config), but I'm getting other > wonderful related problems too on rc3-mm2. On qemu -mm1 boots mostly > without error and then crashes nicely when I type 'ps' with a long pause > for about twenty seconds and then a combination of soft lockups, bitmap > errors, and eventually hits the BUG_ON I put in bitmap_error(). However, > -mm2 also vomits on typing 'ps'. > > It pauses and then spits out (fun lines selected from ps output): > > 7 ? serial8250: too much work for irq4 > 00:00:00 watchdog/1 > 88 ? 00:00:0serial8250: too much work for irq4 > 0 cqueue/1 > 137 ? 00:00serial8250: too much work for irq4 > > :00 aio/0 > > Checking a few /proc files I see that "serial83250" info littered > throughout /proc/stat as well. -mm2 does not oops but the proc output is > variously corrupted. > > Interestingly if I don't type 'ps' in the -mm1 qemu it runs fine with no > sign of a bug... In summary, here I can only reproduce your big fat oops by > it being triggered by some corruption elsewhere on this config related to > /proc breakage that I haven't managed to track down. I checked the > broken-out patches to see which touched /proc and it was oh, most of them. > I tried on rc3 and had the same thing happen. I haven't tried rc3 without > rsdl (your config takes too darn long to build!). /proc appears broken on vanilla -rc3 as well. I did make oldconfig from http://userweb.kernel.org/~akpm/ck/config.txt and chose all the defaults. Then building your fat config with -rc3, 'ps' hangs on qemu for almost 30 seconds and then at last produces a broken output PID TTY TIME CMD 1 ? 00:00:00 init 2 ? 00:00:00 migration/0 3 ? 00:00:00 ksoftirqd/0 4 ? 00:00:00 watchdog/0 5 ? 00:00:00 migration/1 6 ? 00:00:00 ksoftirqd/1 7 ? serial8250: too much work for irq4 00:00:00 watchdog/1 8 ? 00:00:00 events/0 9 ? 00:00:00 events/1 10 ? 00:00:00 khelper 11 ? 00:00:00 kthread 52 ? 00:00:00 kblockd/0 53 ? 00:00:00 kblockd/1 54 ? 00:00:00 kacpid 87 ? 00:00:00 cqueue/0 88 ? 00:00:00 cqueue/1 89 ? 00:00:00 ata/0 90 ? 00:00:00 ata/1 91 ? 00:00:00 ata_aux 92 ? 00:00:00 ksuspend_usbd 95 ? 00:00:00 khubd 97 ? 00:00:00 kseriod 133 ? 00:00:00 pdflush 134 ? 00:00:00 pdflush 135 ? 00:00:00 kserial8250: too much work for irq4 swapd0 136 ? 00:00:00 aio/0 137 ? 00:00:00 aio/1 287 ? 00:00:00 kpsmoused 311 ? 00:00:00 sh 312 ? 00:00:00 ps It's random where this happens too. Sometimes it goes away, other times it's different tasks, and it happens to /proc/stat too -- -ck