Date: Tue, 17 Jul 2007 01:04:19 +0200 From: Milos Vyletel <mv@rulez.sk> To: youshi10@u.washington.edu Cc: hackers@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") Message-ID: <20070716230419.GA95219@rulez.sk> In-Reply-To: <Pine.LNX.4.43.0707161456020.22217@hymn01.u.washington.edu> References: <20070716132326.GA28016@rulez.sk> <Pine.LNX.4.43.0707161456020.22217@hymn01.u.washington.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
> 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<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT> Features2=0x1<SSE3> AMD Features=0xe2500800<SYSCALL,NX,MMX+,FFXSR,LM,3DNow!+,3DNow!> AMD Features2=0x3<LAHF,CMP> 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070716230419.GA95219>