Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755769Ab0KCT3P (ORCPT ); Wed, 3 Nov 2010 15:29:15 -0400 Received: from mail-ew0-f46.google.com ([209.85.215.46]:44561 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753520Ab0KCT3L (ORCPT ); Wed, 3 Nov 2010 15:29:11 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:message-id:user-agent:mime-version :content-type; b=qGcLl32nV5NDkrxFnEzmssjdqQA+9SIyYGp2TbF8/hOloPmPkq/IGAdtIVt6flJl1M QCTmW/fKgjOStfKRTxi7tsegadTUu0dFqj9WKzJG3KQCgEd2/lb3+s8FKnRLzUbXp9xv OGQGLDoO9LAqjVF2u1QPrLBLnJcsNoAUtgTkg= From: Francis Moreau To: linux-kernel@vger.kernel.org Subject: perf tools miscellaneous questions Date: Wed, 03 Nov 2010 20:28:59 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2008 Lines: 53 Hello, I'm trying to use perf-tools and also to learn some internals about them. So I prefer to ask all of them in one email. The first one is about the list of pre-defined events given by perf-list. I couldn't find any documentations that describes these events so excuse me if the question is stupid. What's the difference between 'cpu-clock' and 'task-clock' event ? What's exactly the 'cache-misses' event ? does it include both instructions _and_ data cache misses ? both L1 and L2 caches ? I was expecting so but the following command makes me wondering: $ perf stat -e cache-misses:u,l1d-loads-misses:u true Performance counter stats for 'true': 763 cache-misses 874 L1-dcache-load-misses 0.000916609 seconds time elapsed Here cache-misses < L1-dcache-load-misses. The last question is about the source code annotation done by perf-report. I'm using it to locate the place in my code that generates the most data cache miss events. I can read this during a perf-report session: [...] 0.00 : df215: c3 retq 0.00 : df216: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 0.00 : df21d: 00 00 00 10.00 : df220: 48 8b 75 00 mov 0x0(%rbp),%rsi 80.00 : df224: 48 89 df mov %rbx,%rdi 0.00 : df227: 41 ff d4 callq *%r12 0.00 : df22a: 85 c0 test %eax,%eax [...] If I read the output correctly, most of the dcache misses are coming from 'mov %rbx, %rdi', and AFAIK this intruction can't generate any dcache miss. What am I missing ? Thanks. -- Francis -- 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/