From owner-freebsd-current@FreeBSD.ORG Wed Aug 4 21:19:25 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6FF8616A4CE for ; Wed, 4 Aug 2004 21:19:25 +0000 (GMT) Received: from smtp002.bizmail.yahoo.com (smtp002.bizmail.yahoo.com [216.136.172.126]) by mx1.FreeBSD.org (Postfix) with SMTP id 3C6A043D45 for ; Wed, 4 Aug 2004 21:19:25 +0000 (GMT) (envelope-from noackjr@alumni.rice.edu) Received: from unknown (HELO optimator.noacks.org) (noackjr@supercrime.org@70.240.234.183 with login) by smtp002.bizmail.yahoo.com with SMTP; 4 Aug 2004 21:19:25 -0000 Received: from localhost (localhost [127.0.0.1]) by optimator.noacks.org (Postfix) with ESMTP id F2F496114; Wed, 4 Aug 2004 16:19:23 -0500 (CDT) Received: from optimator.noacks.org ([127.0.0.1]) by localhost (optimator.noacks.org [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 00612-02; Wed, 4 Aug 2004 16:19:22 -0500 (CDT) Received: from compgeek.noacks.org (compgeek [192.168.1.10]) by optimator.noacks.org (Postfix) with ESMTP id 03536610E; Wed, 4 Aug 2004 16:19:21 -0500 (CDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by compgeek.noacks.org (8.13.1/8.13.1) with ESMTP id i74LJKlb075952; Wed, 4 Aug 2004 16:19:21 -0500 (CDT) (envelope-from noackjr@alumni.rice.edu) Message-ID: <411152D8.2050305@alumni.rice.edu> Date: Wed, 04 Aug 2004 16:19:20 -0500 From: Jon Noack User-Agent: Mozilla Thunderbird 0.7.2 (X11/20040802) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jeremy Chadwick References: <1091649533.29481.42.camel@lanshark.dmv.com> <20040804203456.GA46377@parodius.com> In-Reply-To: <20040804203456.GA46377@parodius.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at noacks.org cc: current@freebsd.org Subject: Re: Postgresql locks up server - no response at all X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: noackjr@alumni.rice.edu List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Aug 2004 21:19:25 -0000 On 08/04/04 15:34, Jeremy Chadwick wrote: > I've seen this with our SuperMicro SuperServer 5013C-T, running mysqld. > Please note that the server is "heavily loaded" (note the quotes); usually > a load of around 0.50 to 1.00 at all times, with mysqld being the top > process. Server runs all latest -CURRENT builds. > > Many people over in freebsd-threads mentioned this problem, and recommended > all sorts-of different workarounds. I tried every one available to me, > except mucking with PREEMPTION (as I did not feel comfortable tinkering > with a random .h file on the box; seemed to be a kernel-related thing, > so I'd rather have just an "options" line for it -- I'm conditionally > lazy). The one you didn't try most likely was the culprit. Robert Watson showed that PREEMPTION and threading don't play well together right now: http://lists.freebsd.org/pipermail/freebsd-current/2004-July/031211.html The thought is that PREEMPTION uncovers scheduler bugs, but nobody's figured it out at the moment. > Wed Aug 4 13:28:35 PDT 2004 > * -CURRENT box is still alive and well. PREEMPTION was turned off on August 1st, so if you've updated since then things should have stabilized a bit: http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/i386/include/param.h#rev1.72 Jon