From owner-freebsd-stable@FreeBSD.ORG Mon Feb 3 05:02:53 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id C87A4943 for ; Mon, 3 Feb 2014 05:02:53 +0000 (UTC) Received: from hz.grosbein.net (hz.grosbein.net [78.47.246.247]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 506F11C99 for ; Mon, 3 Feb 2014 05:02:52 +0000 (UTC) Received: from eg.sd.rdtc.ru (root@eg.sd.rdtc.ru [62.231.161.221]) by hz.grosbein.net (8.14.7/8.14.7) with ESMTP id s1352j57047250 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 3 Feb 2014 06:02:46 +0100 (CET) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: freebsd-stable@freebsd.org Received: from eg.sd.rdtc.ru (eugen@localhost [127.0.0.1]) by eg.sd.rdtc.ru (8.14.7/8.14.7) with ESMTP id s1352drN084544; Mon, 3 Feb 2014 12:02:40 +0700 (NOVT) (envelope-from eugen@grosbein.net) Message-ID: <52EF22EF.8010902@grosbein.net> Date: Mon, 03 Feb 2014 12:02:39 +0700 From: Eugene Grosbein User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:17.0) Gecko/20130415 Thunderbird/17.0.5 MIME-Version: 1.0 To: Matthew Rezny Subject: Re: Tuning kern.maxswzone is minor compared to hangs in "kmem a" state References: <20140201070912.00007971@unknown> <20140201221612.00001897@unknown> <20140202204623.00003fe5@unknown> In-Reply-To: <20140202204623.00003fe5@unknown> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-0.7 required=5.0 tests=ALL_TRUSTED,BAYES_00, LOCAL_FROM autolearn=no version=3.3.2 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on eg.sd.rdtc.ru Cc: freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Feb 2014 05:02:53 -0000 On 03.02.2014 02:46, Matthew Rezny wrote: > Just as I was about to hit send, the box panicked. Finally a panic and > not just a hang so there's a backtrace! That should be the first hint > as to where in the kernel I'm hitting trouble. The panic points the > finger at UFS. The filesystem has seen some thrashing but it did just > fsck without significant error before that build was started. So, I'm > thinking it's not on-disk corruption but an in-memory problem. It blew > up writing a softdep, which starts me wondering if the buffers used for > softupdates bookkeeping are overflowing in the kernel. That would make > some sense, rapidly creating (svn/tar) or deleting (rm) many small > files will create a huge amount of activity for softupdates to track, > defer and reorder. The rm case is probably the one than can trigger it > the fastest because deletes are focusing the beating on the metadata > without wasting time between on file data I/O. See also http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/176857