From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Tso Subject: Re: [PATCH 5/5] Dump the inode structure (for debugging purposes only) Date: Thu, 21 May 2009 16:28:40 -0400 Message-ID: <20090521202840.GB9236@mit.edu> References: <1242936063-31689-1-git-send-email-tytso@mit.edu> <1242936063-31689-2-git-send-email-tytso@mit.edu> <1242936063-31689-3-git-send-email-tytso@mit.edu> <1242936063-31689-4-git-send-email-tytso@mit.edu> <1242936063-31689-5-git-send-email-tytso@mit.edu> <1242936063-31689-6-git-send-email-tytso@mit.edu> <20090521200942.GA5110@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Matthew Wilcox Return-path: Received: from thunk.org ([69.25.196.29]:42787 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754453AbZEUU2q (ORCPT ); Thu, 21 May 2009 16:28:46 -0400 Content-Disposition: inline In-Reply-To: <20090521200942.GA5110@parisc-linux.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, May 21, 2009 at 02:09:42PM -0600, Matthew Wilcox wrote: > On Thu, May 21, 2009 at 04:01:03PM -0400, Theodore Ts'o wrote: > > This is not intended for merging; but it's useful for determining how > > much varous fields in the struct inode space, and whether there is any > > padding leading to waste, especially on a 64-bit platforms. > > Why not just use acme's pahole? > Because I didn't know about it, and now that I've looked at it, it requires compiling the kernel with CONFIG_DEBUG_INFO, which means the kernel takes a lot longer to build. What I did is a bit more hackish, to be sure, but it's faster to drop it into the tree and then run it under kvm and then pull it out of the console logs. If you were planning on investigating a large number of structures, acme's solution probably is a better one; but if you only need one, it might be faster to whip up a custom kernel module, perhaps built out of the tree, instead of rebuilding the entire kernel with CONFIG_DEBUG_INFO. - Ted