From owner-freebsd-threads@FreeBSD.ORG Fri Sep 12 22:16:38 2008 Return-Path: <owner-freebsd-threads@FreeBSD.ORG> Delivered-To: freebsd-threads@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E82D9106567C for <freebsd-threads@freebsd.org>; Fri, 12 Sep 2008 22:16:38 +0000 (UTC) (envelope-from ivoras@gmail.com) Received: from rv-out-0506.google.com (rv-out-0506.google.com [209.85.198.229]) by mx1.freebsd.org (Postfix) with ESMTP id B924A8FC0A for <freebsd-threads@freebsd.org>; Fri, 12 Sep 2008 22:16:38 +0000 (UTC) (envelope-from ivoras@gmail.com) Received: by rv-out-0506.google.com with SMTP id b25so1255910rvf.43 for <freebsd-threads@freebsd.org>; Fri, 12 Sep 2008 15:16:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender :to:subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references :x-google-sender-auth; bh=uz5Vbw+yj3c6OmKB1oHx34Oz7GN1kw1nTCskgseqOSU=; b=A3M0fW6ZeNZFfEbYH01A0Yu5Q/JBLxYWE30Y0+8nlAMfB5zYtY7Fr76SRKnp5an9fC 5+3VtrxXoMnq+MOHGrbz1CEgThrpXSAFANLREOzSNQeLY4hkku6gqGrTqo8FtPMdK12T ebrG68fI39Q0ryI8/rJlJcju+sWsztPxuTZdc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=GccV4QItdAw/AhkmhzPkJ2lsXm2Sd48paePPSZOLoJP2OK4wbCTDUsVxgpS9gAJACh 2CbNc0i8vAK2ZTTFO2G8iM++ulSpVMrLZm4kjGjOLaZYIKcbBhuWyqdMrGUyaBgEPQiI DaOE0HwHAkiJkPM+8ucbQtMtA4jxnJwUWo544= Received: by 10.141.137.6 with SMTP id p6mr2905146rvn.279.1221255891221; Fri, 12 Sep 2008 14:44:51 -0700 (PDT) Received: by 10.141.153.13 with HTTP; Fri, 12 Sep 2008 14:44:51 -0700 (PDT) Message-ID: <9bbcef730809121444u34991c52m2cbc01a8ada47eb5@mail.gmail.com> Date: Fri, 12 Sep 2008 23:44:51 +0200 From: "Ivan Voras" <ivoras@freebsd.org> Sender: ivoras@gmail.com To: "Alfred Perlstein" <alfred@freebsd.org> In-Reply-To: <20080912165808.GE16977@elvis.mu.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <gadgrb$4uc$1@ger.gmane.org> <20080912165808.GE16977@elvis.mu.org> X-Google-Sender-Auth: 9219905d203f2681 Cc: freebsd-threads@freebsd.org Subject: Re: Apache-worker stuck at 100% CPU X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Threading on FreeBSD <freebsd-threads.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>, <mailto:freebsd-threads-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-threads> List-Post: <mailto:freebsd-threads@freebsd.org> List-Help: <mailto:freebsd-threads-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>, <mailto:freebsd-threads-request@freebsd.org?subject=subscribe> X-List-Received-Date: Fri, 12 Sep 2008 22:16:39 -0000 2008/9/12 Alfred Perlstein <alfred@freebsd.org>: > Try using "pstack" a few times. It's in ports. > > Also, gcore(1) might help. Will try. > You can also try to attach using gdb. I did, but either I'm missing something or I'm not using it well, because I can't get a backtrace. How do I select threads to backtrace? How do I pick what thread to backtrace? > Basically, one of these tools should give you a stack trace which > can help. > > It's interesting that the process is in "umtxn" though, is it > multithreaded apache? Can you dump the threads? I think top(1) > has an option to view each thread, how about trying that? Yes, it's multithreaded apache. This did help somewhat - when I do it I see that it's not actually stuck in umtxn - there's one thread that consumes the CPU and it's apparently always running (in state CPUx). PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND 7212 www 103 0 30340K 7932K CPU2 2 444:23 99.02% httpd I'm currently upgrading the system to 7-STABLE, to see if it helps.