Date: Mon, 5 Feb 2001 09:34:35 -0800 From: Alfred Perlstein <bright@wintelcom.net> To: Thomas Stratmann <thomas.stratmann@ruhr-uni-bochum.de> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: ktrace sync'ing before panic Message-ID: <20010205093435.N26076@fw.wintelcom.net> In-Reply-To: <3A7EA2FA.E08B958D@ruhr-uni-bochum.de>; from thomas.stratmann@ruhr-uni-bochum.de on Mon, Feb 05, 2001 at 01:56:27PM %2B0100 References: <3A7EA2FA.E08B958D@ruhr-uni-bochum.de>
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* Thomas Stratmann <thomas.stratmann@ruhr-uni-bochum.de> [010205 05:04] wrote: > Hi everyone, > > I had a problem once on a 4.1-stable which does not seem to be fixed by > now. I had mount cause panic under certain circumstances and went to > find the error, first doing ktrace on the call. The result was an empty > ktrace.out as the output was not synchronized/written out do disk before > the actual kernel panic. I went into kern_ktrace.c and inserted a > VOP_FSync call inside ktrwrite and it worked: after the panic, one could > see the last kernel action was a call to mount (into the kernel) - the > first stage of success in debugging. > > I believe the issue of syncing is a tradeoff between speed and > reliability in the (rare) case of a panic. > > One should consider introducing an option to the ktrace call for this - > if the manpage will be elaborate enough about the issue, even > non-hackers will be able to give more precise error mailings. This is an excellent idea, can you open a PR about it? -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] "I have the heart of a child; I keep it in a jar on my desk." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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