From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266555AbUHTLmv (ORCPT ); Fri, 20 Aug 2004 07:42:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266347AbUHTLmv (ORCPT ); Fri, 20 Aug 2004 07:42:51 -0400 Received: from [195.23.16.24] ([195.23.16.24]:50885 "EHLO bipbip.comserver-pie.com") by vger.kernel.org with ESMTP id S266565AbUHTLmt (ORCPT ); Fri, 20 Aug 2004 07:42:49 -0400 Message-ID: <4125E3B6.6090406@grupopie.com> Date: Fri, 20 Aug 2004 12:42:46 +0100 From: Paulo Marques Organization: Grupo PIE User-Agent: Mozilla Thunderbird 0.7.1 (X11/20040626) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Robin Holt Cc: jmerkey@comcast.net, linux-kernel@vger.kernel.org, jmerkey@drdos.com Subject: Re: kallsyms 2.6.8 address ordering References: <081920041810.18883.4124ED110002BABC000049C32200748184970A059D0A0306@comcast.net> <20040819190029.GC1313@lnx-holt.americas.sgi.com> In-Reply-To: <20040819190029.GC1313@lnx-holt.americas.sgi.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-AntiVirus: checked by Vexira MailArmor (version: 2.0.1.16; VAE: 6.27.0.6; VDF: 6.27.0.21; host: bipbip) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Robin Holt wrote: >.... > > It must be useful for people using small memory footprint machines. > Check with the folks doing embedded stuff. > > I remember a discussion about kallsyms and scaling problems with > top reading some /proc/ file. > > Look at this: > http://marc.theaimsgroup.com/?l=linux-kernel&m=108758995727517&w=2 > I posted recently (exactly one week ago) a different approach to this problem that increased kallsyms_lookup performance about 100 times, without a cache and without locking. The patch is currently in Ingo Molnar's tree (I think). It works by doing binary search on tha address table and then using pre-calculated markers on the stem stream to search closer to the target. After that it copies only the stems before the searched symbol that actually contribute to the final result. You can check the thread here: http://marc.theaimsgroup.com/?l=linux-kernel&m=109245918613781&w=2 (Please note that the original patch broke handling of aliased symbols which was corrected later in the thread) I'm working on an even better approach right now and I should have a patch ready this weekend. This however has nothing to do with _module_ symbol names, which is a different problem altogether. -- Paulo Marques - www.grupopie.com