Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 5 Dec 2002 19:52:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 5 Dec 2002 19:52:47 -0500 Received: from packet.digeo.com ([12.110.80.53]:36517 "EHLO packet.digeo.com") by vger.kernel.org with ESMTP id ; Thu, 5 Dec 2002 19:52:46 -0500 Message-ID: <3DEFF69F.481AB823@digeo.com> Date: Thu, 05 Dec 2002 17:00:15 -0800 From: Andrew Morton X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.5.50 i686) X-Accept-Language: en MIME-Version: 1.0 To: Norman Gaywood CC: linux-kernel@vger.kernel.org Subject: Re: Maybe a VM bug in 2.4.18-18 from RH 8.0? References: <20021206111326.B7232@turing.une.edu.au> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 06 Dec 2002 01:00:15.0484 (UTC) FILETIME=[D66CD3C0:01C29CC2] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1664 Lines: 53 Norman Gaywood wrote: > > I think I have a trigger for a VM bug in the RH kernel-bigmem-2.4.18-18 > > 16GB > ... > tar cf /dev/tape . > This machine will die due to buffer_heads which are attached to highmem pagecache, and due to inodes which are pinned by highmem pagecache. > ... > while [ `expr $COUNT - 1` != 0 ] > do > date > # 2000 by 1_000_000 seems to be a 1.8G process > perl -e '$i=2000;while ($i--){ $a[$i]="x"x1_000_000; }' & > ... This will evict the highmem pagecache. That frees the buffer_heads and unpins the inodes. > So what do I do now? I guess talk to Red Hat. These are well-known problems and there should be fixes for them in a "bigmem" kernel. Otherwise, the -aa kernels have patches to address these problems. One option would be to roll your own kernel, based on a kernel.org kernel and a matching patch from http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/ > ... > Anyone have some patches for me to > try that won't take me too far from the RH 8.0 base system. Hard. The relevant patches are: http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.20aa1/05_vm_16_active_free_zone_bhs-1 and http://www.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.20aa1/10_inode-highmem-2 The first one will not come vaguely close to applying to an RH 2.4.18 kernel. The second one may well apply, and will probably fix the problem. - 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/