From owner-freebsd-hackers@FreeBSD.ORG Fri Sep 11 19:14:47 2009 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E574C1065694 for ; Fri, 11 Sep 2009 19:14:47 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id B5E9D8FC13 for ; Fri, 11 Sep 2009 19:14:47 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 66A3946B52; Fri, 11 Sep 2009 15:14:47 -0400 (EDT) Received: from jhbbsd.hudson-trading.com (unknown [209.249.190.8]) by bigwig.baldwin.cx (Postfix) with ESMTPA id 7E1348A01B; Fri, 11 Sep 2009 15:14:46 -0400 (EDT) From: John Baldwin To: Linda Messerschmidt Date: Fri, 11 Sep 2009 15:06:47 -0400 User-Agent: KMail/1.9.7 References: <237c27100908261203g7e771400o2d9603220d1f1e0b@mail.gmail.com> <200909111102.14503.jhb@freebsd.org> <237c27100909111035y544e8c91hc7726fd6ef16e351@mail.gmail.com> In-Reply-To: <237c27100909111035y544e8c91hc7726fd6ef16e351@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200909111506.47309.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Fri, 11 Sep 2009 15:14:46 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.5 required=4.2 tests=AWL,BAYES_00,RDNS_NONE autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: freebsd-hackers@freebsd.org Subject: Re: Intermittent system hangs on 7.2-RELEASE-p1 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Sep 2009 19:14:48 -0000 On Friday 11 September 2009 1:35:00 pm Linda Messerschmidt wrote: > On Fri, Sep 11, 2009 at 11:02 AM, John Baldwin wrote: > > Try turning off KTR_LOCK for spin mutexes (just force LO_QUIET on in > > mtx_init() if MTX_SPIN is set) > > I have *no* idea what you just said. :) > > Which is fine. But more to the point, I have no idea how to do it. :) Something like this: Index: sys/kern/kern_mutex.c =================================================================== --- sys/kern/kern_mutex.c (.../mirror/FreeBSD/stable/7) (revision 195943) +++ sys/kern/kern_mutex.c (.../stable/7) (revision 195943) @@ -747,6 +747,10 @@ if (opts & MTX_NOPROFILE) flags |= LO_NOPROFILE; + /* XXX: Only log for regular mutexes. */ + if (opts & MTX_SPIN) + flags |= LO_QUIET; + /* Initialize mutex. */ m->mtx_lock = MTX_UNOWNED; m->mtx_recurse = 0; > > A more recently schedgraph.py might also > > fix the bugs you were seeing with the idle threads looking too long (esp. at > > the start and end of graphs). > > We are already on RELENG_7 due to the KTR-enabling rebuild, so that'd > be the version we're using unless, as Julian observed, it's been fixed > in the past week or so. Hmm. It works well for me for doing traces. -- John Baldwin