From owner-freebsd-hackers@FreeBSD.ORG Tue Jul 17 18:21:09 2007 Return-Path: X-Original-To: hackers@freebsd.org Delivered-To: freebsd-hackers@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 23E8B16A403; Tue, 17 Jul 2007 18:21:09 +0000 (UTC) (envelope-from youshi10@u.washington.edu) Received: from mxout7.cac.washington.edu (mxout7.cac.washington.edu [140.142.32.178]) by mx1.freebsd.org (Postfix) with ESMTP id 0381A13C467; Tue, 17 Jul 2007 18:21:08 +0000 (UTC) (envelope-from youshi10@u.washington.edu) Received: from hymn01.u.washington.edu (hymn01.u.washington.edu [140.142.8.55]) by mxout7.cac.washington.edu (8.13.7+UW06.06/8.13.7+UW07.06) with ESMTP id l6HIL8Fq004537 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 17 Jul 2007 11:21:08 -0700 Received: from localhost (localhost [127.0.0.1]) by hymn01.u.washington.edu (8.13.7+UW06.06/8.13.7+UW07.03) with ESMTP id l6HIL7Ce030430; Tue, 17 Jul 2007 11:21:07 -0700 X-Auth-Received: from [192.55.52.10] by hymn01.u.washington.edu via HTTP; Tue, 17 Jul 2007 11:21:07 PDT Date: Tue, 17 Jul 2007 11:21:07 -0700 (PDT) From: youshi10@u.washington.edu To: Milos Vyletel In-Reply-To: <20070716231345.GA43427@rulez.sk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-PMX-Version: 5.3.2.304607, Antispam-Engine: 2.5.1.298604, Antispam-Data: 2007.7.17.105933 X-Uwash-Spam: Gauge=IIIIIII, Probability=7%, Report='NO_REAL_NAME 0, __C230066_P5 0, __CT 0, __CT_TEXT_PLAIN 0, __HAS_MSGID 0, __MIME_TEXT_ONLY 0, __MIME_VERSION 0, __SANE_MSGID 0' Cc: hackers@freebsd.org, current@freebsd.org Subject: Re: Large amounts of memory access operations cause panic under CURRENT (was "Large gap between fwrite and write, and fread and read") X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Jul 2007 18:21:09 -0000 On Tue, 17 Jul 2007, Milos Vyletel wrote: >>> Go figure it'd cause panics for other people. >>> >>> I wasn't using zfs at all but it panicked anyhow once (my amd64 VM only, >>> not my i386 test server, surprisingly). I wish I'd gotten the panic but I >>> walked away to get a glass of water, and there wasn't a core dump because >>> the VM shut down completely instead of restarting. Heh. >>> >>> My virtual machine died around 90k on the first trial though. I'll be sure >>> to reduce the amount and see what happens, and I'll put nanosleeps or >>> usleeps between the read and write ops to see if that alleviates the race >>> condition seen, but I'll keep the problem code around for reference later >>> in case I've stimulated some sort of weird bug in FreeBSD, or otherwise. >>> >>> Both my VM and test server run almost no programs though other than samba >>> and rsync, so you'll probably see the panic faster / more frequently than I >>> will if you run a lot more programs resident in memory. >>> >>> Just curious, what scheduler are you using on CURRENT, what processor do >>> you have, and what are your memory specs? >>> >>> Thanks, >>> -Garrett >>> >> Hi Garrett, >> >> this is just my desktop where is running only Xorg, fluxbox, few aterms and >> firefox. But i can get the panic on console too, shortly after booting. I'm >> using SCHED_ULE. >> >> CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ (2205.01-MHz K8-class >> CPU) >> Origin = "AuthenticAMD" Id = 0x20f32 Stepping = 2 >> Features=0x178bfbff >> Features2=0x1 >> AMD Features=0xe2500800 >> AMD Features2=0x3 >> Cores per package: 2 >> usable memory = 3211718656 (3062 MB) >> avail memory = 3105570816 (2961 MB) >> >> For the record, it crashes few times before it hit 100k iterations, before i >> put >> debug printf in your code and increase MAX_ITERATIONS to 1m. And as far as I >> can tell, I had pretty much the same results as you've measured. >> >> mv > > Sorry for the noise, forgot to CC current@ This seems to be resolved with the latest CURRENT sources and ULE patches. -Garrett