From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933194AbYBVXIu (ORCPT ); Fri, 22 Feb 2008 18:08:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758159AbYBVXIk (ORCPT ); Fri, 22 Feb 2008 18:08:40 -0500 Received: from el-out-1112.google.com ([209.85.162.178]:48888 "EHLO el-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757821AbYBVXIh (ORCPT ); Fri, 22 Feb 2008 18:08:37 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:mime-version:content-type:content-transfer-encoding:content-disposition; b=iudWDumlljII084sYrsHMW1s/Uw+CAbIvsmVkVJrGcVQ7wEwh9avW0JfUxlL3KDRxaMufIn/KRar34dQIqX/q8YfBVVazB6brlL4HE9OCIp9nC25zx8BTCGItqDY00ReN0s5gzdnjTUrruT049PSrz8X0OJFrwTW7cswkIt80Dw= Message-ID: <8abd1bfd0802221508i373d37e7hd6ad7702bde25330@mail.gmail.com> Date: Fri, 22 Feb 2008 18:08:34 -0500 From: "Stephen Oberholtzer" To: linux-kernel@vger.kernel.org Subject: How to diagnose a process stuck in D state? Cc: oliverklozoff@gmail.com MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org First off: I'm not subscribed to the list (I don't think I could handle the volume), so please make sure you CC me if you reply. I run an application on one of my machines; it often hangs, with the process stuck D state. When this happens, the process sticks around until I reboot the machine. I have tried the following to start diagnosing the problem: * Running 'ps -axl' shows "-" in the wchan column. * The contents of /proc/pid/wchan say "_stext". * 'strace -p pid' says "Process pid attached - interrupt to quit" and stops responding. Sending SIGINT and SIGTERM have no effect on the strace process, although kill -11 (SIGSEGV, my personal favorite) does work. This is very confusing. I would greatly appreciate it if someone could tell me how a process can enter D state without being in a syscall, and what I can do to start tracking down the cause. (By the way: This is on amd64, 2.6.23. I'm updating to 2.6.24.2 right now, on the off chance that whatever was causing the problem has been fixed.) -- -- Stevie-O Real programmers use COPY CON PROGRAM.EXE