From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B44F2C4708A for ; Thu, 27 May 2021 11:59:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96A5461006 for ; Thu, 27 May 2021 11:59:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234562AbhE0MAc (ORCPT ); Thu, 27 May 2021 08:00:32 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38897 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234447AbhE0MAb (ORCPT ); Thu, 27 May 2021 08:00:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622116737; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=wjPIN2JnhuUc4ncCd4AUurBqU2Abl/WhHOre8Sqosdk=; b=dVr33mHxAo5UQXE1gIwvwiNgTEqgCokvy2SDWpPyGbgCZlawzdowRsxe4PEvzQ47yjapbn 7xDr9rPO73ND2AjO3qQOrPmm+o8ECeWvSjmGQXhdDD6hkBV4KyjQcQL/97fSukxIbLpvO7 o6Hox7t26B31jPqHGIV3upnAjJ/95W0= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-25-iK5Gz3YfOCC7-xWjiOXLMA-1; Thu, 27 May 2021 07:58:56 -0400 X-MC-Unique: iK5Gz3YfOCC7-xWjiOXLMA-1 Received: by mail-ed1-f72.google.com with SMTP id b8-20020a05640202c8b029038f1782a77eso180282edx.15 for ; Thu, 27 May 2021 04:58:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=wjPIN2JnhuUc4ncCd4AUurBqU2Abl/WhHOre8Sqosdk=; b=jWzd5L3Di+7DXfjKHNQ9lAvZ2NOSH6G3+E0V8TjBJxKdI0a/BPuXMmO/MC0kYGbeRq aWLd76ZKvZkoGLL9//gLcMZ/Pad6KbmaUi8FQDa3jlI4waMnVDsa6xI41RurmLHZkfuQ hHdviekpB8sbxh3QzQdJZ+vIcRxVOoKPWDvb6mMzN20Pc1cxYiOH63r95K41lwLYSH7F v9cUfHd0yr73RV514Bq+IzSAalsbgW6ThhlqaJgdzH40QKU8QuQCOeTgh52XeXcQA/zf FEANwPl0WfskWcFn0RL/vPck6LOe/b0tSa7Z/h6ujHIr26CUZrCseYyWwB5l5nzxKs2b YY4A== X-Gm-Message-State: AOAM533KFY+3Xq9rsDxA1ziNLQSLPkkvl4EXxVI9cyMklvnNm5tEpEpU l4V46NLixnnCJ2+EGtkOnlC3LDlbYZfPfIbbfkRtLOF1uF6xWH96GRMfjQ/l+s7YJRqCCiRMKOB ZY8tEu2fvs6PaCK+YLzWnpzcX X-Received: by 2002:a17:906:40cf:: with SMTP id a15mr3413628ejk.181.1622116734868; Thu, 27 May 2021 04:58:54 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyI4hefZVEXGQJKCWltH1Y1Bc9bZRIv+jfizbEcnuKXGxBcsLjympjaoZ9j+8ttg8WO7W2pJg== X-Received: by 2002:a17:906:40cf:: with SMTP id a15mr3413610ejk.181.1622116734710; Thu, 27 May 2021 04:58:54 -0700 (PDT) Received: from localhost.localdomain ([151.29.18.58]) by smtp.gmail.com with ESMTPSA id v16sm890216ejr.65.2021.05.27.04.58.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 May 2021 04:58:54 -0700 (PDT) Date: Thu, 27 May 2021 13:58:52 +0200 From: Juri Lelli To: Daniel Bristot de Oliveira Cc: linux-kernel@vger.kernel.org, Phil Auld , Sebastian Andrzej Siewior , Kate Carcia , Jonathan Corbet , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexandre Chartre , Clark Willaims , John Kacur , linux-doc@vger.kernel.org Subject: Re: [PATCH V3 4/9] tracing/hwlat: Implement the per-cpu mode Message-ID: References: <187db3f9eed1603c858a1f7669d0140dfb753bfd.1621024265.git.bristot@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <187db3f9eed1603c858a1f7669d0140dfb753bfd.1621024265.git.bristot@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 14/05/21 22:51, Daniel Bristot de Oliveira wrote: [...] > +/** > + * start_per_cpu_kthread - Kick off the hardware latency sampling/detector kthreads > + * > + * This starts the kernel threads that will sit on potentially all cpus and > + * sample the CPU timestamp counter (TSC or similar) and look for potential > + * hardware latencies. > + */ > +static int start_per_cpu_kthreads(struct trace_array *tr) > +{ > + struct cpumask *current_mask = &save_cpumask; > + struct cpumask *this_cpumask; > + struct task_struct *kthread; > + char comm[24]; > + int cpu; > + > + if (!alloc_cpumask_var(&this_cpumask, GFP_KERNEL)) > + return -ENOMEM; Is this_cpumask actually used anywhere? Thanks, Juri