From mboxrd@z Thu Jan 1 00:00:00 1970 From: Milian Wolff Subject: task-clock vs. cpu-clock; per-event documentation Date: Wed, 05 Aug 2015 14:55:11 +0200 Message-ID: <1472439.mytDSkIAAG@milian-kdab2> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from dd17628.kasserver.com ([85.13.138.83]:35281 "EHLO dd17628.kasserver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751357AbbHEMzO (ORCPT ); Wed, 5 Aug 2015 08:55:14 -0400 Received: from milian-kdab2.localnet (unknown [185.28.184.2]) by dd17628.kasserver.com (Postfix) with ESMTPSA id 33E666280295 for ; Wed, 5 Aug 2015 14:55:12 +0200 (CEST) Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: linux-perf-users@vger.kernel.org Hello all, I was asked by a colleague of mine what the difference between task-clock and cpu-clock is. I found many similar questions on the web, but none have a final answer: http://stackoverflow.com/questions/23965363/linux-perf-events-cpu-clock-and-task-clock-what-is-the-difference https://lkml.org/lkml/2010/11/3/373 Could someone explain the difference between the two counters for a non-kernel person? What is a task for that matter? When I compare the counters on test applications, they deviate only marginally. In general, is there hope for more documentation on the individual performance counters? Perf list shows what's available but has no information whatsoever about the actual meaning of the counters. It would be excellent to also explain how to interpret the counter, or in what case you'd want to look at a given event. Thanks -- Milian Wolff mail@milianw.de http://milianw.de