From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756922AbXLUQTH (ORCPT ); Fri, 21 Dec 2007 11:19:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752258AbXLUQSy (ORCPT ); Fri, 21 Dec 2007 11:18:54 -0500 Received: from nf-out-0910.google.com ([64.233.182.190]:2956 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751579AbXLUQSx (ORCPT ); Fri, 21 Dec 2007 11:18:53 -0500 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=X4A2GHBjYlmBv8CTYtlIYfWMqcSddwNYnkii0QG5LSfwYTOmAUmKxiOgYY4Gia9oFuNekhCbbPCCOm+n7voG28UIQslWNlYYFTkcuTKNwT12osHgEoWFs6QZP2Qo2gOp1M1RBYlDRIXkTm0oYXuwTb89tt07Zu+sbEN0EF0JDSk= Message-ID: <2c0942db0712210818q1a16291au3b3ddf395867542a@mail.gmail.com> Date: Fri, 21 Dec 2007 08:18:50 -0800 From: "Ray Lee" To: "Christian Hammers" Subject: Re: Debugging process hanging in D status and not responding to SIGKILL Cc: linux-kernel@vger.kernel.org In-Reply-To: <20071221163845.6fa3f2a9@sys-251.netcologne.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20071221163845.6fa3f2a9@sys-251.netcologne.de> X-Google-Sender-Auth: 62129dcdf4d28e07 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Dec 21, 2007 7:38 AM, Christian Hammers wrote: > Hello > > Occasionally all my apache2 processes hang in "D" process status where they are > no longer responsible to SIGKILL which makes the server almost un-rebootable. > The processes usually vanish after about 15-30min. > > I know that this usually means "I/O wait" somewhere deep inside a kernel > function where signals are not handled. > > But using "strace -p " I can only see that the last called function is > flock() (according to /proc//fd somebody produced a deadlock when using > PHP sessions). But flock() normally terminates on SIGTERM and SIGKILL. > > Could it be a problem with my SCSI driver who's involed in the flock process? > The problem usually occurs on two other webserver at the same time, one using > the same hardware and one being a Dell 6850 with Dell PERC RAID, though. > > How can I get further debugging information that could give me a hint? Do an echo t >/proc/sysrq-trigger and see what it shows.