Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265148AbUFHBUy (ORCPT ); Mon, 7 Jun 2004 21:20:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265152AbUFHBUy (ORCPT ); Mon, 7 Jun 2004 21:20:54 -0400 Received: from c3p0.cc.swin.edu.au ([136.186.1.30]:21521 "EHLO swin.edu.au") by vger.kernel.org with ESMTP id S265148AbUFHBUt (ORCPT ); Mon, 7 Jun 2004 21:20:49 -0400 To: John Bradford Cc: William Lee Irwin III , Nick Piggin , Michael Brennan , linux-kernel@vger.kernel.org From: Tim Connors Subject: Re: why swap at all? In-reply-to: <200406010910.i519AWsm000213@81-2-122-30.bradfords.org.uk> References: <40BB88B5.8080300@ezrs.com> <200405312029.i4VKTCZ0000596@81-2-122-30.bradfords.org.uk> <40BBB5F7.1010407@yahoo.com.au> <200406010834.i518Y1cT000414@81-2-122-30.bradfords.org.uk> <20040601083206.GI2093@holomorphy.com> <200406010850.i518o8PD000134@81-2-122-30.bradfords.org.uk> <20040601085456.GJ2093@holomorphy.com> <200406010910.i519AWsm000213@81-2-122-30.bradfords.org.uk> X-Face: m+g#A-,3D0}Ygy5KUD`Hckr=I9Au;w${NzE;Iz!6bOPqeX^]}KGt=l~r!8X|W~qv'`Ph4dZczj*obWD25|2+/a5.$#s23k"0$ekRhi,{cP,CUk=}qJ/I1acc Message-ID: Date: Tue, 8 Jun 2004 11:18:49 +1000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6507 Lines: 117 John Bradford said on Tue, 1 Jun 2004 10:10:32 +0100: > Quote from William Lee Irwin III : > > Quote from William Lee Irwin III : > > > to reproduce these 'swap increases performance even with untouched RAM' > > > claims. > > > > Because ZONE_DMA, the lower 16MB is not all of RAM. > > Ah, OK, this isn't really my area of expertise so maybe this is a stupid, (for > LKML), question, but can we only migrate data from low RAM via swap!? > > Also, surely this is only relevant to X86 architectures? I just got an interesting problem - possibly (or not?) related to this: I have my laptop with 256MB of RAM, running 2.4.25-pre7, uptime 48 days. Every morning, I come in and have to wait 2 minutes while everything comes back into RAM, after the daily slocate. So I did a swapoff -a, and it failed despite all the applications and cache and tmpfs adding up to far less than 256MB (more like 128). I closed mozilla, which let me do a swapoff -a. All was well for a few days, but then thismorning, my partitions were mounted ro, and an oops was in syslog at the same time as all the slocate work: Jun 8 07:55:24 scuzzie kernel: VM: killing process xemacs Jun 8 07:56:17 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:56:17 scuzzie kernel: VM: killing process mailoops Jun 8 07:57:30 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d0/0) Jun 8 07:57:34 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:35 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:35 scuzzie kernel: VM: killing process sh Jun 8 07:57:35 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:35 scuzzie kernel: VM: killing process sh Jun 8 07:57:38 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:38 scuzzie kernel: VM: killing process ssh-agent Jun 8 07:57:38 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:38 scuzzie kernel: VM: killing process gunzip Jun 8 07:57:40 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:40 scuzzie kernel: VM: killing process gunzip Jun 8 07:57:40 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:40 scuzzie kernel: VM: killing process gunzip Jun 8 07:57:41 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d0/0) Jun 8 07:57:41 scuzzie kernel: ERROR: (device ide0(3,5)): txAbortCommit Jun 8 07:57:41 scuzzie kernel: BUG at jfs_txnmgr.c:509 assert(tblk->next == 0) Jun 8 07:57:41 scuzzie kernel: kernel BUG at jfs_txnmgr.c:509! Jun 8 07:57:41 scuzzie kernel: invalid operand: 0000 Jun 8 07:57:41 scuzzie kernel: CPU: 0 Jun 8 07:57:41 scuzzie kernel: EIP: 0010:[txEnd+235/256] Not tainted Jun 8 07:57:41 scuzzie kernel: EFLAGS: 00010282 Jun 8 07:57:41 scuzzie kernel: eax: 00000033 ebx: d0811c98 ecx: c12dc000 edx: cd9f5f7c Jun 8 07:57:41 scuzzie kernel: esi: 00000102 edi: cfec1d60 ebp: cf4eb000 esp: c12ddf18 Jun 8 07:57:41 scuzzie kernel: ds: 0018 es: 0018 ss: 0018 Jun 8 07:57:41 scuzzie kernel: Process keventd (pid: 2, stackpage=c12dd000) Jun 8 07:57:41 scuzzie kernel: Stack: c028ed43 c028f190 000001fd c028f180 fffffffb 00000102 cf4eb05c c017db9e Jun 8 07:57:41 scuzzie kernel: 00000102 00000001 c12ddf54 00000000 00000000 c35c5220 c017dc0e c35c5220 Jun 8 07:57:41 scuzzie kernel: 00000000 00000001 c014d3f2 c35c5220 00000000 00000003 c12ddf88 c12ddf88 Jun 8 07:57:41 scuzzie kernel: Call Trace: [jfs_commit_inode+222/256] [jfs_write_inode+78/96] [try_to_sync_unused_inodes+466/480] [__run_task_queue+90/112] [cont ext_thread+442/448] Jun 8 07:57:41 scuzzie kernel: [context_thread+0/448] [rest_init+0/64] [arch_kernel_thread+46/64] [context_thread+0/448] Jun 8 07:57:41 scuzzie kernel: Jun 8 07:57:41 scuzzie kernel: Code: 0f 0b fd 01 90 f1 28 c0 e9 71 ff ff ff 90 8d b4 26 00 00 00 Jun 8 07:57:41 scuzzie kernel: <5>__alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:41 scuzzie kernel: VM: killing process gunzip Jun 8 07:57:49 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1d2/0) Jun 8 07:57:49 scuzzie kernel: VM: killing process mozilla-bin Jun 8 07:57:49 scuzzie kernel: __alloc_pages: 0-order allocation failed (gfp=0x1f0/0) Jun 8 07:58:09 scuzzie wwwoffles[25878]: Cannot make a lock file for 'http/www.bom.gov.au/LkdPT+cpeS73Lf-picjpvUw' [Read-only file system]. Jun 8 07:58:58 scuzzie anacron[16529]: Job `cron.weekly' terminated (exit status: 1) (mailing output) Jun 8 07:58:59 scuzzie modprobe: modprobe: cannot create /var/log/ksymoops/20040608.log Read-only file system Jun 8 07:58:59 scuzzie modprobe: modprobe: cannot create /var/log/ksymoops/20040608.log Read-only file system Jun 8 07:58:59 scuzzie anacron[16529]: Tried to mail output of job `cron.weekly', but mailer process (/usr/sbin/sendmail) exited with ststus 1 Jun 8 07:58:59 scuzzie anacron[16529]: Normal exit (2 jobs run) So OOM - but why? The cache was registering 65MB used. 24353,23> cat /proc/meminfo total: used: free: shared: buffers: cached: Mem: 262647808 256618496 6029312 0 4820992 67239936 Swap: 0 0 0 MemTotal: 256492 kB MemFree: 5888 kB MemShared: 0 kB Buffers: 4708 kB Cached: 65664 kB SwapCached: 0 kB Active: 77944 kB Inactive: 142308 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 256492 kB LowFree: 5888 kB SwapTotal: 0 kB SwapFree: 0 kB Why was it so eager to kill applications, and not reclaim some of that swap space? Is this a problem that is known on 2.4, and can't be fixed (I can't use 2.6 on my laptop yet, far too many problems to even start - eg the suspend to ram on APM thread). Is there another output of a /proc file you want? I'll try not to get the urge to use/reboot the box in the meantime. -- TimC -- http://astronomy.swin.edu.au/staff/tconnors/ Anyone seeking the "Relativistic Quantum Mechanics" soft option course, may wish to leave now. -- Intro lecture to RQM - 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/