From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750891AbXCDXDh (ORCPT ); Sun, 4 Mar 2007 18:03:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752518AbXCDXDh (ORCPT ); Sun, 4 Mar 2007 18:03:37 -0500 Received: from 41-052.adsl.zetnet.co.uk ([194.247.41.52]:4862 "EHLO mail.esperi.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750891AbXCDXDf (ORCPT ); Sun, 4 Mar 2007 18:03:35 -0500 To: Corey Hickey Cc: linux-kernel@vger.kernel.org Subject: Re: CONFIG_PREEMPT -> crash under load in 2.6.20? References: <87d53qxbzi.fsf@hades.wkstn.nix> <45EB1C44.1000702@fatooh.org> From: Nix Emacs: more than just a Lisp interpreter, a text editor as well! Date: Sun, 04 Mar 2007 23:03:25 +0000 In-Reply-To: <45EB1C44.1000702@fatooh.org> (Corey Hickey's message of "Sun, 04 Mar 2007 11:21:40 -0800") Message-ID: <871wk41uiq.fsf@hades.wkstn.nix> User-Agent: Gnus/5.1007 (Gnus v5.10.7) XEmacs/21.5-b27 (linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-DCC--Metrics: hades 1356; Body=2 Fuz1=2 Fuz2=2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 4 Mar 2007, Corey Hickey told this: > Nix wrote: >> I can't tell if magic sysrq dies, because as far as I know there's no >> way to get magic sysrq to do much visible when you're in X, and I can't >> get anything to go over the network kernel syslog because the network is >> dead. > > You should still be able to use SysRQ even in X. I tested right now. > 1. Have X running already and then start X in another VT > $ X :2 vt10 > 2. Hit Alt+SysRQ+K > ---> X dies, display gets corrupted, and keyboard input ignored > 3. ssh in from another machine and switch back to the running X instance > # chvt 7 The network's dead; that's impossible. However, I'll try SAK followed by a reg-and-flags dump: I'd entirely forgotten about SAK. If that doesn't work I'll try to get a kexec dump. (This is all moot if, as seems likely, the system's too dead to respond to the keyboard: we shall see.) >> I could begin a (really laborious, ~1 day per iteration) bisection to >> try to track this down, but before I start, has anyone seen this before? >> Is its cause known? > > I've been seeing the same behavior under different circumstances; I > don't know if it's related. > > http://www.uwsg.iu.edu/hypermail/linux/kernel/0703.0/1147.html That's using _VOLUNTARY, so I sort of doubt that it's the *same* problem, but I suppose it might be related. (But this is hypothesis in the absence of data :) ) > For me, though, CONFIG_PREEMPT doesn't seem to have an effect. One thing > I had noticed, however, is that with the problem I'm experiencing, > changing some config options inexplicably delayed the onset of the > lockup, but the lockup occurred nonetheless. Have you been running with > CONFIG_PREEMPT_VOLUNTARY for a while now and not seen any problems at all? 22:58:47 up 10 days, 22:20, 37 users, load average: 12.71, 11.14, 18.22 No problems, and I've been loading the system really rather hard today (as that line makes clear). I think the problem I'm seeing really *is* tied to _PREEMPT. > It might be helpful if you reported your hardware information; I'd be > interested in seeing if there's much in common with my own machine. Athlon 4 (UP), 768Mb RAM. No ACPI (to rule out a large nasty spot as soon as possible). Random info starting with loaded modules: loop 11080 0 - Live 0xf0a56000 radeon 107808 2 - Live 0xf0a5c000 drm 62356 3 radeon, Live 0xf0a2f000 processor : 0 vendor_id : AuthenticAMD cpu family : 6 model : 6 model name : AMD Athlon(tm) Processor stepping : 2 cpu MHz : 1250.178 cache size : 256 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow ts bogomips : 2501.59 clflush size : 32 CPU0 0: 944756984 IO-APIC-edge timer 1: 1397516 IO-APIC-edge i8042 2: 0 XT-PIC-XT cascade 6: 5 IO-APIC-edge floppy 7: 0 IO-APIC-edge parport0 8: 1 IO-APIC-edge rtc 12: 2877936 IO-APIC-edge i8042 14: 20262275 IO-APIC-edge ide2 16: 330856361 IO-APIC-fasteoi EMU10K1, radeon@pci:0000:01:00.0 18: 115648745 IO-APIC-fasteoi gordianet 19: 11059053 IO-APIC-fasteoi ide0, ide1 21: 0 IO-APIC-fasteoi uhci_hcd:usb1, uhci_hcd:usb2 NMI: 0 LOC: 944792893 ERR: 0 MIS: 49 0000-001f : dma1 0020-0021 : pic1 0040-0043 : timer0 0050-0053 : timer1 0060-006f : keyboard 0070-0077 : rtc 0080-008f : dma page reg 00a0-00a1 : pic2 00c0-00df : dma2 00f0-00ff : fpu 0170-0177 : 0000:00:11.1 01f0-01f7 : 0000:00:11.1 01f0-01f7 : ide2 0295-0296 : w83627hf 0376-0376 : 0000:00:11.1 0378-037a : parport0 037b-037f : parport0 03c0-03df : vga+ 03f2-03f5 : floppy 03f6-03f6 : 0000:00:11.1 03f6-03f6 : ide2 03f7-03f7 : floppy DIR 03f8-03ff : serial 0400-0407 : vt596_smbus 0cf8-0cff : PCI conf1 b000-bfff : PCI Bus #01 b800-b8ff : 0000:01:00.0 c800-c81f : 0000:00:11.2 c800-c81f : uhci_hcd cc00-cc1f : 0000:00:11.3 cc00-cc1f : uhci_hcd d000-d07f : 0000:00:07.0 d400-d41f : 0000:00:05.0 d400-d41f : EMU10K1 d800-d80f : 0000:00:0c.0 d800-d807 : ide0 d808-d80f : ide1 dc00-dc03 : 0000:00:0c.0 dc02-dc02 : ide1 e000-e007 : 0000:00:0c.0 e000-e007 : ide1 e400-e403 : 0000:00:0c.0 e402-e402 : ide0 e800-e807 : 0000:00:0c.0 e800-e807 : ide0 ec00-ec07 : 0000:00:05.1 ec00-ec07 : emu10k1-gp fc00-fc0f : 0000:00:11.1 fc00-fc07 : ide2 fc08-fc0f : ide3 Here's some lspci output: 00:00.0 Host bridge: VIA Technologies, Inc. VT8366/A/7 [Apollo KT266/A/333] Subsystem: VIA Technologies, Inc. Unknown device 0000 Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- Status: Cap+ 66MHz+ UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- SERR- TAbort- SERR- TAbort- Reset- FastB2B- Capabilities: [80] Power Management version 2 Flags: PMEClk- DSI- D1+ D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 PME-Enable- DSel=0 DScale=0 PME- 00:05.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 04) Subsystem: Creative Labs CT4620 SBLive! Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR-