Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758027AbZIFPvz (ORCPT ); Sun, 6 Sep 2009 11:51:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757998AbZIFPvw (ORCPT ); Sun, 6 Sep 2009 11:51:52 -0400 Received: from THUNK.ORG ([69.25.196.29]:54555 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758001AbZIFPvv (ORCPT ); Sun, 6 Sep 2009 11:51:51 -0400 Date: Sun, 6 Sep 2009 11:51:47 -0400 From: Theodore Tso To: devzero@web.de Cc: linux-kernel@vger.kernel.org Subject: Re: block_dump - full path ? Message-ID: <20090906155147.GH3055@mit.edu> Mail-Followup-To: Theodore Tso , devzero@web.de, linux-kernel@vger.kernel.org References: <899288751@web.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <899288751@web.de> User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@mit.edu X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1856 Lines: 35 On Sat, Sep 05, 2009 at 11:44:35PM +0200, devzero@web.de wrote: > Hi, > > i came across the nice debugging feature sysctl vm.block_dump=1 which leaves information on read/write in dmesg for every process. > > Sep 5 20:11:15 neoware kernel: kjournald(423): WRITE block 155542512 on sda2 > Sep 5 20:11:15 neoware kernel: kjournald(423): WRITE block 155542520 on sda2 > Sep 5 20:11:15 neoware kernel: kjournald(423): WRITE block 155542528 on sda2 > Sep 5 20:11:19 neoware kernel: pdflush(14): WRITE block 144498288 on sda2 > Sep 5 20:11:19 neoware kernel: pdflush(14): WRITE block 144916496 on sda2 > Sep 5 20:11:19 neoware kernel: pdflush(14): WRITE block 144917376 on sda2 > Sep 5 20:11:19 neoware kernel: pdflush(14): WRITE block 144704600 on sda2 > > is it possible to log the full path of the process ? What do you mean by "the full path of the process"? Do you mean the full path of the process' executable? (In this case kjournald and pdflush are kernel threads so there is no executable, and thus there is no "full path". unless you mean pathname to the kernel, i.e., /vmlinux.) Or did you mean the full path name of the file associated with the block number? In this case, kjournald is writing to the file system journal, which has no pathname. pdflush is writing dirty pages from the page cache, which could be mapped to file names, but it would take up a huge amount of space in the log -- but to what effect? What exactly are you trying to do? There might be a more efficient way of gathering whatever data you are trying to get for your experiment. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/