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[2620:137:e000::1:20]) by mx.google.com with ESMTP id xo19-20020a170907bb9300b0096f6c947d69si4864016ejc.356.2023.06.11.20.05.30; Sun, 11 Jun 2023 20:05:54 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229477AbjFLCfy (ORCPT + 99 others); Sun, 11 Jun 2023 22:35:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229902AbjFLCfv (ORCPT ); Sun, 11 Jun 2023 22:35:51 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7855B19A; Sun, 11 Jun 2023 19:35:49 -0700 (PDT) Received: from kwepemi500013.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4QfbJr4gx3zqTm2; Mon, 12 Jun 2023 10:30:52 +0800 (CST) Received: from M910t.huawei.com (10.110.54.157) by kwepemi500013.china.huawei.com (7.221.188.120) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 12 Jun 2023 10:35:46 +0800 From: Changbin Du To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo CC: Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , , , , Changbin Du Subject: [PATCH] perf/doc: revise the description about PR_TASK_PERF_EVENTS_{ENABLE,DISABLE} Date: Mon, 12 Jun 2023 10:35:23 +0800 Message-ID: <20230612023523.3918618-1-changbin.du@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.110.54.157] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemi500013.china.huawei.com (7.221.188.120) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1768464480315142606?= X-GMAIL-MSGID: =?utf-8?q?1768464480315142606?= The behavior of PR_TASK_PERF_EVENTS_{ENABLE,DISABLE} has been changed since v2.6.30, commit 082ff5a2767a ("perf_counter: Change pctrl() behaviour"). This patch revises the documentation about these two prctl options to match the real behavior. The linux man pages should also be updated. Cc: Ingo Molnar Cc: Peter Zijlstra Signed-off-by: Changbin Du --- tools/perf/design.txt | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/tools/perf/design.txt b/tools/perf/design.txt index aa8cfeabb743..cc9a2716d5ec 100644 --- a/tools/perf/design.txt +++ b/tools/perf/design.txt @@ -439,16 +439,15 @@ Additionally, non-inherited overflow counters can use to enable a counter for 'nr' events, after which it gets disabled again. -A process can enable or disable all the counter groups that are -attached to it, using prctl: +A thread can enable or disable all the counter groups that are +created by itself, using prctl: prctl(PR_TASK_PERF_EVENTS_ENABLE); prctl(PR_TASK_PERF_EVENTS_DISABLE); -This applies to all counters on the current process, whether created -by this process or by another, and doesn't affect any counters that -this process has created on other processes. It only enables or +This applies to all counters created by this thread, and doesn't affect any +counters that created by other processes or threads. It only enables or disables the group leaders, not any other members in the groups.