Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753766Ab2EaFyp (ORCPT ); Thu, 31 May 2012 01:54:45 -0400 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:54050 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752861Ab2EaFyX (ORCPT ); Thu, 31 May 2012 01:54:23 -0400 X-AuditID: 9c93016f-b7c3cae000001954-03-4fc7078cac62 From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Peter Zijlstra , Paul Mackerras , Ingo Molnar , Namhyung Kim , LKML Subject: [PATCH 2/3] perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP Date: Thu, 31 May 2012 14:51:45 +0900 Message-Id: <1338443506-25009-2-git-send-email-namhyung.kim@lge.com> X-Mailer: git-send-email 1.7.10.2 In-Reply-To: <1338443506-25009-1-git-send-email-namhyung.kim@lge.com> References: <1338443506-25009-1-git-send-email-namhyung.kim@lge.com> X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1463 Lines: 39 The ioctl interface of perf event fd receives 3 arguments to control event group behavior but it lacked documentation. Signed-off-by: Namhyung Kim --- tools/perf/design.txt | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/perf/design.txt b/tools/perf/design.txt index bd0bb1b1279b..67e5d0cace85 100644 --- a/tools/perf/design.txt +++ b/tools/perf/design.txt @@ -409,14 +409,15 @@ Counters can be enabled and disabled in two ways: via ioctl and via prctl. When a counter is disabled, it doesn't count or generate events but does continue to exist and maintain its count value. -An individual counter or counter group can be enabled with +An individual counter can be enabled with - ioctl(fd, PERF_EVENT_IOC_ENABLE); + ioctl(fd, PERF_EVENT_IOC_ENABLE, 0); or disabled with - ioctl(fd, PERF_EVENT_IOC_DISABLE); + ioctl(fd, PERF_EVENT_IOC_DISABLE, 0); +For a counter group, pass PERF_IOC_FLAG_GROUP as the third argument. Enabling or disabling the leader of a group enables or disables the whole group; that is, while the group leader is disabled, none of the counters in the group will count. Enabling or disabling a member of a -- 1.7.10.2 -- 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/