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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C06E9C4332F for ; Sun, 29 Oct 2023 12:17:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230108AbjJ2MRB (ORCPT ); Sun, 29 Oct 2023 08:17:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229790AbjJ2MQ7 (ORCPT ); Sun, 29 Oct 2023 08:16:59 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E5D9BF; Sun, 29 Oct 2023 05:16:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=GiwSQA1MEgbGgyq4T6GAbLNQiLBl/gGNQhi2kVQa80I=; b=39befQj3i+pcJMQrF0ILvxffit D3iEoBgq1jvN4DfaeRGXuwGcLmVbNnwbzCCkR3TNhfxiryoLb1RIDK98VVYrpc4AR3WTsdknVynoV TQG4uD9kXx+qnv/0poIv/3euA5q7cjLG052wF9mLUtDXI6gaxPUUm2rULKvWbRX7r7aIZP5SWhFiB 3IfJ+HtPiF2sS2Jvn0ggQVky3RicUBi2d8vxkA5luz4AJexE0V/B9OjADLa/pHSfoQt8Z2Hqdoq6S J7m0MgScfHDDH6MrG1S/yOcIoJZbkz6coAkF0V0VzQRZVtK4N/GX5kGW626tyU5UpepZdPJ6361Dh geo1ii5w==; Received: from [50.53.46.231] (helo=[192.168.254.15]) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qx4in-001j7D-1t; Sun, 29 Oct 2023 12:16:49 +0000 Message-ID: <2e507e97-8ac6-43a2-a290-e0e80af0d044@infradead.org> Date: Sun, 29 Oct 2023 05:16:49 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3] PM: sleep: Expose last succeeded resumed timestamp in sysfs Content-Language: en-US To: "Masami Hiramatsu (Google)" Cc: "Rafael J . Wysocki" , Pavel Machek , Len Brown , suleiman@google.com, briannorris@google.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org References: <169849758243.1357961.4105003693126485611.stgit@mhiramat.roam.corp.google.com> <20231029115449.8c942b131312c2464eda6970@kernel.org> From: Randy Dunlap In-Reply-To: <20231029115449.8c942b131312c2464eda6970@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi. On 10/28/23 19:54, Masami Hiramatsu (Google) wrote: > On Sat, 28 Oct 2023 09:48:36 -0700 > Randy Dunlap wrote: > >> Hi, >> >> On 10/28/23 05:53, Masami Hiramatsu (Google) wrote: >>> From: Masami Hiramatsu >>> >>> Expose last succeeded resumed timestamp as last_success_resume_time >>> attribute of suspend_stats in sysfs. This timestamp is recorded in >>> CLOCK_MONOTONIC. So user can find the actual resumed time and >>> measure the elapsed time from the time when the kernel finished >>> the resume to the user-space action (e.g. display the UI). >> >> Can you go into the use-case a bit more, please? >> You have said "what", but not "why". >> What do you (or google) plan to do with this? and what about this part of my questions? ^^^^^^^^^ >> >>> >>> Signed-off-by: Masami Hiramatsu (Google) >>> --- >>> Changes in v3: >>> - Add (unsigned long long) casting for %llu. >>> - Add a line after last_success_resume_time_show(). >>> Changes in v2: >>> - Use %llu instead of %lu for printing u64 value. >>> - Remove unneeded indent spaces from the last_success_resume_time >>> line in the debugfs suspend_stat file. >>> --- >>> Documentation/ABI/testing/sysfs-power | 10 ++++++++++ >>> include/linux/suspend.h | 2 ++ >>> kernel/power/main.c | 15 +++++++++++++++ >>> kernel/power/suspend.c | 1 + >>> 4 files changed, 28 insertions(+) >>> >>> diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power >>> index a3942b1036e2..63659765dee1 100644 >>> --- a/Documentation/ABI/testing/sysfs-power >>> +++ b/Documentation/ABI/testing/sysfs-power >>> @@ -442,6 +442,16 @@ Description: >>> 'total_hw_sleep' and 'last_hw_sleep' may not be accurate. >>> This number is measured in microseconds. >>> >>> +What: /sys/power/suspend_stats/last_success_resume_time >>> +Date: Oct 2023 >>> +Contact: Masami Hiramatsu >>> +Description: >>> + The /sys/power/suspend_stats/last_success_resume_time file >>> + contains the timestamp of when the kernel successfully >>> + resumed from suspend/hibernate. >>> + This floating number is measured in seconds by monotonic >> >> What does "floating" mean here? Not floating point... > > Oops, it should be "floating point number". > > Thank you! > >> >> >>> + clock. >>> + >>> What: /sys/power/sync_on_suspend >>> Date: October 2019 >>> Contact: Jonas Meurer >> >> [snip] >> >> Thanks. >> -- >> ~Randy > > -- ~Randy