Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264059AbTEWOtb (ORCPT ); Fri, 23 May 2003 10:49:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264067AbTEWOtb (ORCPT ); Fri, 23 May 2003 10:49:31 -0400 Received: from holomorphy.com ([66.224.33.161]:55443 "EHLO holomorphy") by vger.kernel.org with ESMTP id S264059AbTEWOta (ORCPT ); Fri, 23 May 2003 10:49:30 -0400 Date: Fri, 23 May 2003 08:02:22 -0700 From: William Lee Irwin III To: "Martin J. Bligh" Cc: Dave Hansen , Andrew Morton , lkml , linux-mm@kvack.org Subject: Re: 2.5.69-mm8 Message-ID: <20030523150222.GC19818@holomorphy.com> Mail-Followup-To: William Lee Irwin III , "Martin J. Bligh" , Dave Hansen , Andrew Morton , lkml , linux-mm@kvack.org References: <20030522021652.6601ed2b.akpm@digeo.com> <17990000.1053670694@[10.10.2.4]> <1053673399.1547.27.camel@nighthawk> <26160000.1053700350@[10.10.2.4]> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <26160000.1053700350@[10.10.2.4]> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1368 Lines: 28 At some point in the past, Dave Hansen removed Martin Bligh's attribution from: >>> 1004 2.0% default_idle >>> 272 8.3% __copy_from_user_ll >>> 129 1.7% __d_lookup >>> 79 7.5% link_path_walk At some point in the past, Martin Bligh removed Dave Hansen's attribution from: >> I have to wonder if these are cache effects, or just noise. Can you >> give oprofile a try with one of the cache performance counters? On Fri, May 23, 2003 at 07:32:31AM -0700, Martin J. Bligh wrote: > No, but you can ;-) Cache things are usually link order and .config dependent, in 2.4.x at least they were highly dependent on cache color conflicts between task structures and hot codepaths and similar bizarre phenomena. i.e. exact binutils, compiler, kernel source, and .config matches are required to reproduce. And sometimes even that isn't enough and it's not reproducible across runs. You also want instruction-level multiplicative differential profiling to find cacheline bounces, not function-level additive differential profiling, with some method of correlating assembly to source. -- wli - 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/