From owner-freebsd-current Mon Apr 29 8: 2:11 2002 Delivered-To: freebsd-current@freebsd.org Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by hub.freebsd.org (Postfix) with ESMTP id 1B71637B427; Mon, 29 Apr 2002 08:02:04 -0700 (PDT) Received: from fledge.watson.org (fledge.pr.watson.org [192.0.2.3]) by fledge.watson.org (8.11.6/8.11.6) with SMTP id g3TF1ow34894; Mon, 29 Apr 2002 11:01:50 -0400 (EDT) (envelope-from robert@fledge.watson.org) Date: Mon, 29 Apr 2002 11:01:50 -0400 (EDT) From: Robert Watson X-Sender: robert@fledge.watson.org To: John Baldwin Cc: jeff@FreeBSD.org, current@FreeBSD.org Subject: Re: page fault in _mtx_lock_flags In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, 29 Apr 2002, John Baldwin wrote: > On 29-Apr-2002 Robert Watson wrote: > > > > If I apply the attached diff to the kern_malloc.c, backing out a portion > > of kern_malloc.c:1.99, the rate of panics plummets. Previously, I could > > have a box panic within five minutes of getting the crash boxes spinning. > > Now I've been going for about 40 minutes without any perceived failures > > (i.e., no panics). I have no idea why this fixes the problem, but David > > Wolfskill pointed me at that particular revision as being a source of > > related problems for him. I'm going to leave the boxes running overnight > > and see what I bump into. It would be nice to know if this is masking the > > problem, or fixing the problem, and if so, why. > > You have memory corruption it looks like. I think the patch adds new > buckets of larger sizes. Perhaps the problem is a bug in uma where > someone allocates something bigger than the largest bucket, and the > chunk they get back is only the size of an item in the largest bucket, > thus when the code writes to the end of the structure it is overwriting > other memory. That was what I was theorizing when I made the change, but I haven't really had much time lately to read the UMA code, so it's greek to me. :-) Robert N M Watson FreeBSD Core Team, TrustedBSD Project robert@fledge.watson.org NAI Labs, Safeport Network Services To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message