From owner-freebsd-current Sat Jan 23 11:56:11 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA09203 for freebsd-current-outgoing; Sat, 23 Jan 1999 11:56:11 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA09198 for ; Sat, 23 Jan 1999 11:56:10 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.2/8.9.1) id LAA48625; Sat, 23 Jan 1999 11:55:49 -0800 (PST) (envelope-from dillon) Date: Sat, 23 Jan 1999 11:55:49 -0800 (PST) From: Matthew Dillon Message-Id: <199901231955.LAA48625@apollo.backplane.com> To: Peter Wemm Cc: current@FreeBSD.ORG Subject: Re: panic: found dirty cache page 0xf046f1c0 References: <199901231943.DAA00782@spinner.netplex.com.au> Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :[..] :> > Try changing the panic in vm/vm_page.c to a printf() ( :> :> I'll do that. : :BTW; what are the dangers of this? lost disk writes or corruption? Can :we (as a workaround) push the page that we found back onto a dirty queue :and try again after some diagnostics? That's ok, don't worry about it... Doug's debug output gives me the same info. :It crashed in uniprocessor mode about 60 seconds after sending this mail. :It's got a really trimmed down kernel config and no modules loaded or in :use. I have not disabled softupdates yet, that's next. I don't get it.... why can't I reproduce this problem? Can you email me your kernel configuration? Are you using any special devices like vn or something ? :Oh, one other thing that occurred to me.. Under 4.0-current, I regularly :(ie: within 30 seconds of boot) get if_de tranmitter underflows. My :console corruption was happening at the instant that de0 was being :configured with ifconfig. exmh is running to a remote display over that :de0 interface. : :Under Jan 16 3.0-current, I do not get that tranmitter underflow.. : :The only thin I can think of about if_de that's unusual that is VM related :(apart from the complexity of the code) is that it uses configmalloc(). I :wonder if this is somehow setting the scene for the later failures? It's :certainly suspicious that has done strange things when being ifconfig'ed, :including things like trashing the serial console on no less than a dozen :occasions. : :Cheers, :-Peter Hmmm.. HMMMMMM. contigmalloc, eh? You might be onto something here. I will investigate it. The problem was are having is that, somehow, a vm_page_t in the PQ_CACHE is being set dirty. Sinc vm_page_cache() panics if m->dirty is set, then m->dirty must be getting set *after* the page has been moved to the cache. contigmalloc() looks suspicious. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message