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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 02F82C352AA for ; Tue, 1 Oct 2019 19:37:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D196A21783 for ; Tue, 1 Oct 2019 19:37:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Z18GCOhV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726229AbfJAThF (ORCPT ); Tue, 1 Oct 2019 15:37:05 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:35480 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726180AbfJAThF (ORCPT ); Tue, 1 Oct 2019 15:37:05 -0400 Received: by mail-pg1-f195.google.com with SMTP id a24so10419077pgj.2 for ; Tue, 01 Oct 2019 12:37:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=C7sOqQNedkcx0oCS8qMJJDlwDpOYg3wAh4V6d+6Y9us=; b=Z18GCOhVkcmnAppiVtHPtC432SZzbQ0CPVKlFMwn4NlnV8o8ElXiCmyMbopSXkwISq buEszM7lUB7HW+11kOfbMcZpfHkAf+93d+cY7hOguSnaWBexkIAAyoQtU7V9crqvZO/K Js8OCGwxgJ7wYZHApTtbC+H/sCtsZfMViUWUc= 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:user-agent; bh=C7sOqQNedkcx0oCS8qMJJDlwDpOYg3wAh4V6d+6Y9us=; b=q3gWjzpDSOYvCwYArIRaaSbwZyX+Z1jdhXg5qgEvvRhJseO8pG5d1tyT6pB9kAuNIa x60hFWj1nMzb7/UP0Gk2ThWla8VenwAi+EnqSPRIRGL17+JvTeO4ETschHJBtYiiRpGj YPhwEy6huDIFnNvlV7SE13B07Aa+nLBfjVaIw3XN+Ui8EgtcNeqSnwp9w4ZcdqeeJSse +FdktZOxp9xwp+nFVIHGks8Wpc646DhMEd7H7bTPJZoxx10qKQiH7HU8nsSZqUxrEHZ4 DeeZtsPZ/fiTjTLcneT3AekCeKbpBvS4n16BskU2+kxNIBMfqMruRWnL1SajyGOoFFMs zQog== X-Gm-Message-State: APjAAAUXFjRx4FXPa1zjLJ17Dwta2f3rXyCHtM9sFAMIc/rRsYzqRmeh wm9QBdHRk5bIcdtgzrnfnWyYOw== X-Google-Smtp-Source: APXvYqzgc+nnPoSiGwwK5dMvZe3vh+x52mbB8Hmzp3uWe6KiEKdzdVkFq5+0RZu54v9/oU/j3jycgg== X-Received: by 2002:a17:90a:c8a:: with SMTP id v10mr7357813pja.4.1569958623489; Tue, 01 Oct 2019 12:37:03 -0700 (PDT) Received: from localhost ([2620:15c:202:1:4fff:7a6b:a335:8fde]) by smtp.gmail.com with ESMTPSA id w134sm16471589pfd.4.2019.10.01.12.37.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 01 Oct 2019 12:37:02 -0700 (PDT) Date: Tue, 1 Oct 2019 12:37:01 -0700 From: Matthias Kaehlcke To: Steven Rostedt Cc: "Rafael J . Wysocki" , Kevin Hilman , Ulf Hansson , Len Brown , Pavel Machek , Greg Kroah-Hartman , Ingo Molnar , Douglas Anderson , linux-pm@vger.kernel.org, Amit Kucheria , linux-kernel@vger.kernel.org, Ravi Chandra Sadineni Subject: Re: [PATCH v1] PM / Domains: Add tracepoints Message-ID: <20191001193701.GD87296@google.com> References: <20190926150406.v1.1.I07a769ad7b00376777c9815fb169322cde7b9171@changeid> <20190927044239.589e7c4c@oasis.local.home> <20191001163542.GB87296@google.com> <20191001130343.4480afe3@gandalf.local.home> <20191001174235.GC87296@google.com> <20191001140846.65d7866c@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191001140846.65d7866c@gandalf.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Tue, Oct 01, 2019 at 02:08:46PM -0400, Steven Rostedt wrote: > On Tue, 1 Oct 2019 10:42:35 -0700 > Matthias Kaehlcke wrote: > > > On Tue, Oct 01, 2019 at 01:03:43PM -0400, Steven Rostedt wrote: > > > On Tue, 1 Oct 2019 09:35:42 -0700 > > > Matthias Kaehlcke wrote: > > > > > > > How about this instead: > > > > > > > > Add tracepoints for genpd_power_on, genpd_power_off and > > > > genpd_set_performance_state. The tracepoints can help with > > > > understanding power domain behavior of a given device, which > > > > may be particularly interesting for battery powered devices > > > > and suspend/resume. > > > > > > Do you have a use case example to present? > > > > TBH I'm not looking into a specific use case right now. While > > peeking around in /sys/kernel/debug/tracing/events to learn more > > about existing tracepoints that might be relevant for my work > > I noticed the absence of genpd ones and it seemed a good idea to > > add them preemptively. Conceptually they seem similar to the > > existing regulator_enable/disable and cpu_idle tracepoints. > > > > As an abstract use case I could see power analysis on battery > > powered devices during suspend. genpd_power_on/off allow to see > > which power domains remain on during suspend, and might give > > insights for possible power saving options. Examples could be that > > a power domain stays unexpectedly on due to a misconfiguration, or > > two power domains remain on when it could be only one if you just > > moved that one pin/port over to the other domain in the next > > hardware revision. > > If the power management maintainers have no issues with adding these, > then neither do I ;-) It would be them who would pull them in anyway. Ok, I'll send a new version with the changes you suggested and some more info in the commit message, unless PM maintainers raise concerns before that.