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[2620:137:e000::1:20]) by mx.google.com with ESMTP id lf4-20020a170902fb4400b001a1ba217a6dsi3912458plb.506.2023.03.19.10.13.40; Sun, 19 Mar 2023 10:13:57 -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 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231126AbjCSQsU (ORCPT + 99 others); Sun, 19 Mar 2023 12:48:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230518AbjCSQry (ORCPT ); Sun, 19 Mar 2023 12:47:54 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D5181E9E8; Sun, 19 Mar 2023 09:47:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D322EB80C85; Sun, 19 Mar 2023 16:47:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79B09C433A1; Sun, 19 Mar 2023 16:47:49 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1pdwCC-000JXr-1X; Sun, 19 Mar 2023 12:47:48 -0400 Message-ID: <20230319164748.290057187@goodmis.org> User-Agent: quilt/0.66 Date: Sun, 19 Mar 2023 12:46:46 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , stable@vger.kernel.org, Tero Kristo , Daniel Bristot de Oliveira Subject: [for-linus][PATCH 3/8] trace/hwlat: Do not wipe the contents of per-cpu thread data References: <20230319164643.513018619@goodmis.org> MIME-Version: 1.0 X-Spam-Status: No, score=-4.0 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS 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?1760817093476229125?= X-GMAIL-MSGID: =?utf-8?q?1760817093476229125?= From: Tero Kristo Do not wipe the contents of the per-cpu kthread data when starting the tracer, as this will completely forget about already running instances and can later start new additional per-cpu threads. Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/ Link: https://lkml.kernel.org/r/20230310100451.3948583-2-tero.kristo@linux.intel.com Cc: stable@vger.kernel.org Fixes: f46b16520a087 ("trace/hwlat: Implement the per-cpu mode") Signed-off-by: Tero Kristo Acked-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_hwlat.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index d440ddd5fd8b..edc26dc22c3f 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -584,9 +584,6 @@ static int start_per_cpu_kthreads(struct trace_array *tr) */ cpumask_and(current_mask, cpu_online_mask, tr->tracing_cpumask); - for_each_online_cpu(cpu) - per_cpu(hwlat_per_cpu_data, cpu).kthread = NULL; - for_each_cpu(cpu, current_mask) { retval = start_cpu_kthread(cpu); if (retval)