Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965851Ab2FAWUM (ORCPT ); Fri, 1 Jun 2012 18:20:12 -0400 Received: from merlin.infradead.org ([205.233.59.134]:54287 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759564Ab2FAWQw (ORCPT ); Fri, 1 Jun 2012 18:16:52 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Namhyung Kim , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Arnaldo Carvalho de Melo Subject: [PATCH 07/15] perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP Date: Fri, 1 Jun 2012 19:16:31 -0300 Message-Id: <1338588999-32509-8-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.7.9.2.358.g22243 In-Reply-To: <1338588999-32509-1-git-send-email-acme@infradead.org> References: <1338588999-32509-1-git-send-email-acme@infradead.org> Content-Type: text/plain; charset="UTF-8" X-SRS-Rewrite: SMTP reverse-path rewritten from by canuck.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1758 Lines: 46 From: Namhyung Kim The ioctl interface of perf event fd receives 3 arguments to control event group behavior but it lacked documentation. Signed-off-by: Namhyung Kim Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1338443506-25009-2-git-send-email-namhyung.kim@lge.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/design.txt | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/perf/design.txt b/tools/perf/design.txt index bd0bb1b..67e5d0c 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 -- 1.7.1 -- 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/