From owner-freebsd-stable@FreeBSD.ORG Tue May 12 06:12:29 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4B8311065674; Tue, 12 May 2009 06:12:29 +0000 (UTC) (envelope-from pluknet@gmail.com) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id 9C9B48FC15; Tue, 12 May 2009 06:12:28 +0000 (UTC) (envelope-from pluknet@gmail.com) Received: by bwz9 with SMTP id 9so3116654bwz.43 for ; Mon, 11 May 2009 23:12:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=7+L83x8Aj8bwZ1QBdH4FNwdxvFazpxd4pT37v0ULZbI=; b=gSzZtmD+jhey/BqIagZnP8VJL+2wcRP0IIzga+15JH5ia8UHLwMc/tos64+rW20nw/ pN65mhRFxQ/nuyESP7xCzJxrdOJ3wIEP4DykXlEA6t6SZRrgphESv5tQV9+tQXK2Bfc9 Jj5GUquWmss6cIQ2nm6oibhMLxaGTvzHWeOSc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=A3Eit8n9nDusEO52scOI5Dh6TXVRrIJMGqbbQXHJDtdAI4UFAeXWZDrKxHifjHNF7/ zM8EoD5hJNLYZhXHhfs/1zHNL8hQUOOIvLDuw4hE1ACuyiPhMjwEkiSMMGDDwU7f6gPZ ROMFmiuP/zYyTkdg1IHTcfn9hk46ixyoHJ1Fw= MIME-Version: 1.0 Received: by 10.102.247.10 with SMTP id u10mr1728635muh.76.1242108747035; Mon, 11 May 2009 23:12:27 -0700 (PDT) In-Reply-To: <200905110949.31142.jhb@freebsd.org> References: <200905010949.45927.jhb@freebsd.org> <200905110949.31142.jhb@freebsd.org> Date: Tue, 12 May 2009 10:12:27 +0400 Message-ID: From: pluknet To: John Baldwin Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org Subject: Re: lock up in 6.2 (procs massively stuck in Giant) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 May 2009 06:12:29 -0000 2009/5/11 John Baldwin : > On Monday 04 May 2009 11:41:35 pm pluknet wrote: >> 2009/5/1 John Baldwin : >> > On Thursday 30 April 2009 2:36:34 am pluknet wrote: >> >> Hi folks. >> >> >> >> Today I got a new locking issue. >> >> This is the first time I got it, and it's merely reproduced. >> >> >> >> The box has lost both remote connection and local access. >> >> No SIGINFO output on the local console even. >> >> Jumping in ddb> shows the next: >> >> >> >> 1) first, this is a 8-way web server. No processes on runqueue except one >> > httpd >> >> (i.e. ps shows R in its state): >> > >> > You need to find who owns Giant and what that thread is doing. You can > try >> > using 'show lock Giant' as well as 'show lockchain 11568'. >> > >> >> Hi, John! >> >> Just reproduced now on another box. >> Hmm.. stack of the process owing Giant looks garbled. >> >> db> show lock Giant >> class: sleep mutex >> name: Giant >> flags: {DEF, RECURSE} >> state: {OWNED, CONTESTED} >> owner: 0xd0d79320 (tid 102754, pid 34594, "httpd") >> >> db> show lockchain 34594 >> thread 102754 (pid 34594, httpd) running on CPU 7 >> db> show lockchain 102754 >> thread 102754 (pid 34594, httpd) running on CPU 7 > > The thread is running, so we don't know what it's top of stack is and you > can't a good stack trace in that case. > > None of your CPUs are idle, so I don't think you have any sort of deadlock. > You might have a livelock. > > -- > John Baldwin > I'm curious if it could be caused by heavy load. I don't know what it might be definitely, as it's non-trivial for me to determine the reason of a livelock, and to debug it. So I think it may have sense to try 7.x, as there has been done much locking work. Thank you. -- wbr, pluknet