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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 94EB7C32751 for ; Wed, 7 Aug 2019 20:40:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D4CA217F4 for ; Wed, 7 Aug 2019 20:40:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565210438; bh=dEVWiMcN/i+5g27FiRG8nl9VL8HoSbDNVvUAKixHmrg=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=zRY7fACjU414NqV2KbJB0GEyBK3ct6nr0z2JrdcyK9jDf1ulSJyDt2Uu8o5QykI1Y PAadPcHDXtth+AeTV26x2sM1bP9Npfp85yFiO9w0pCk5NClWj2zgFnQwInpFVErJgv M+8Do5e+QIdpAevE9usSi0HLyvswh1Z7l4jTnmkQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389297AbfHGUkh (ORCPT ); Wed, 7 Aug 2019 16:40:37 -0400 Received: from mail-ot1-f66.google.com ([209.85.210.66]:36047 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388428AbfHGUkg (ORCPT ); Wed, 7 Aug 2019 16:40:36 -0400 Received: by mail-ot1-f66.google.com with SMTP id r6so109675680oti.3; Wed, 07 Aug 2019 13:40:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Hsr+7IuYZ22l7OIvx3fQa1mKuz2z9lcudCb1f5vrKBw=; b=lEhV3X4YTQyW9sc35BXtfzvcHrJqfkUliJ6bzuDTWcGFqYi21PFP5dHOqusDQW0vxL EJ/p2Gs3LKGEdSskQdd0La2eCtnAEvM6sgv9lyylrCIYr3xREzaFMyzjho0xzBBK5uxH F5J1oIfXhau/C0scn76ub9QbaZC/i7H4rQdPZq9z8fA5tV3G5Z/hS6uJQJ6jYkM+lS45 BA+UR6JnjLjrtjUwmxGz8HxZeNm/24qzjZZiDqIpc9NfSwH25p0G8nwJY36EqR291AmS C+PNEbObw2vKTWcEiHRQ+G492FRFGHDp89DiA0rmFKYlf+/8SPuYnLKIokTxxZ9yj7fg VWGg== X-Gm-Message-State: APjAAAUvSVkwbV2m2iy3NlgogmgwXqcPcQ/BaWXIoYXYxgf4X0XwryQP O8+L4Lr5ZFZTy3q83p/u927sTZn0MNXNWejgxms= X-Google-Smtp-Source: APXvYqwbzYP+gDUmu7cbwPvt0vp7/DQxqVeeAZBEikWiVadypsE38JfE9Mz9EtZXqcgJs9TJ1uyeDx8pGAkHEMmP/og= X-Received: by 2002:a9d:6b96:: with SMTP id b22mr9983761otq.262.1565210435206; Wed, 07 Aug 2019 13:40:35 -0700 (PDT) MIME-Version: 1.0 References: <20190807153340.11516-1-douglas.raillard@arm.com> In-Reply-To: <20190807153340.11516-1-douglas.raillard@arm.com> From: "Rafael J. Wysocki" Date: Wed, 7 Aug 2019 22:40:23 +0200 Message-ID: Subject: Re: [PATCH] sched/cpufreq: Align trace event behavior of fast switching To: Douglas RAILLARD Cc: Linux Kernel Mailing List , Linux PM , "Rafael J. Wysocki" , Viresh Kumar , Ingo Molnar , Peter Zijlstra Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 7, 2019 at 5:34 PM Douglas RAILLARD wrote: > > Fast switching path only emits an event for the CPU of interest, whereas the > regular path emits an event for all the CPUs that had their frequency changed, > i.e. all the CPUs sharing the same policy. > > With the current behavior, looking at cpu_frequency event for a given CPU that > is using the fast switching path will not give the correct frequency signal. Do you actually have any systems where that is a problem? If so, then what are they?