From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262138AbUEKFYb (ORCPT ); Tue, 11 May 2004 01:24:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263040AbUEKFYb (ORCPT ); Tue, 11 May 2004 01:24:31 -0400 Received: from mtvcafw.sgi.com ([192.48.171.6]:40613 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S263020AbUEKFY2 (ORCPT ); Tue, 11 May 2004 01:24:28 -0400 X-Mailer: exmh version 2.6.3_20040314 03/14/2004 with nmh-1.0.4 From: Keith Owens To: Rusty Russell Cc: Andrew Morton , Andi Kleen , randy.dunlap@osdl.org, Sam Ravnborg , lkml - Kernel Mailing List Subject: Re: [PATCH] Sort kallsyms in name order: kernel shrinks by 30k In-reply-to: Your message of "Tue, 11 May 2004 15:08:55 +1000." <1084252135.31802.312.camel@bach> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 11 May 2004 15:23:28 +1000 Message-ID: <22374.1084253008@kao2.melbourne.sgi.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 11 May 2004 15:08:55 +1000, Rusty Russell wrote: >Admittedly, anyone who sets CONFIG_KALLSYMS doesn't care about space, >it's a fairly trivial change. > >Name: Sort Kallsyms for Stem Compression >Status: Booted on 2.6.6 >Depends: Misc/kallsyms-include-aliases.patch.gz > >Leaving the symbols sorted by name rather than address, so stem >compression works more effectively. Saves a little over 30k here. Not sure this is a good idea. proc_pid_wchan() calls kallsyms_lookup() and has been identified as a bottleneck on systems with a large number of processes. top can consume a complete cpu out of 128 cpus, all because of this bottleneck. I was toying with the idea of doing a binary chop on the address lookup, but this patch prevents that fix.