Date: Sat, 16 Feb 2008 22:07:31 +0100 From: Juergen Lock <nox@jelal.kn-bremen.de> To: MFL Commissioner <mfl-commissioner@marino.st> Cc: freebsd-current@freebsd.org Subject: Re: 7.0 RC2 kernel panic with Kqemu/AMD64 Message-ID: <20080216210731.GA40417@saturn.kn-bremen.de> In-Reply-To: <47B7352B.1040302@marino.st> References: <43555.82.234.78.29.1203154742.squirrel@secure.synsport.net> <20080216175811.GA33393@saturn.kn-bremen.de> <47B7352B.1040302@marino.st>
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On Sat, Feb 16, 2008 at 08:10:35PM +0100, MFL Commissioner wrote: > Juergen, > I would be happy to help debug this, although someone would have to give me > step by step instructions on what to do exactly. > This is a development machine that (roughly) mirrors a production setup, so > I have maintain the SMP/AMD64 configuration. > What I am still not quite clear on is this: Is this a Qemu problem or > FreeBSD kernel problem? I guess its a kqemu problem that only shows up on FreeBSD, or a combination of issues in kqemu and the FreeBSD kernel, but as I said the actual cause of the problem is still unknown... > > Anyway, I'll do what you ask to provide you with my backtraces, but I doubt > that I will be able to interpret the results. OK, I guess you want to start here: http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug.html and http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug-gdb.html And of course you want to build a debug kernel (makeoptions DEBUG=-g), building a kernel is explained here: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig-building.html I also had to put DDB into the kernel so that it gets built without -fomit-frame-pointer (you probably want KDB_UNATTENDED then too, and KDB_TRACE while you're at it.) Oh and I guess you want to disable minidumps also (sysctl debug.minidump=0), there's a race in there that might(!) cause not so useful dumps otherwise. Then when you have a dump, post a script(1) of a `bt' in kgdb, and we'll see if it tells more than the backtraces I got... Thanx, Juergen
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