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 2B0F1C4167D for ; Sun, 29 Oct 2023 02:54:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229918AbjJ2Cy6 (ORCPT ); Sat, 28 Oct 2023 22:54:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbjJ2Cy4 (ORCPT ); Sat, 28 Oct 2023 22:54:56 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A58ECC; Sat, 28 Oct 2023 19:54:54 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15A4DC433C8; Sun, 29 Oct 2023 02:54:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698548094; bh=RlNnNHHg3zRkH0P4DdOqNoxHNDzPt997A9kWx4EOy2U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PkFdZLt+Z30Qeqi8MWYZD+cvxIxKF1wHGbjVs6fEo/KOjmoMLe+FA5SdAJOXTo+Ue 1MEEZrhmot6/KaGa01niJaSzan2FkmIiTdnCnhAV6AAo1g2CpaXL7A5z+pf6q62wJC 1TNn4y9TLnaOlRTnjx5eODYidMsl8OF2ZjnuGKQByK1wWJVZJE0LCvsiGlxY93HFiv JcYBUqcuC7NE5+b37DgPSEH7UCrIXIgxD1mVbYiDubcwq9aOHDY8DXK6uJ86GYZ+Pt 4Qo7VhTnwcJfN6MCNSGJ60s8NdRJHxvgWIfnm/SszxEIkJwzrQaBFhq8CbD99vfqaI TrD2LnnAGsDpQ== Date: Sun, 29 Oct 2023 11:54:49 +0900 From: Masami Hiramatsu (Google) To: Randy Dunlap Cc: "Rafael J . Wysocki" , Pavel Machek , Len Brown , suleiman@google.com, briannorris@google.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH v3] PM: sleep: Expose last succeeded resumed timestamp in sysfs Message-Id: <20231029115449.8c942b131312c2464eda6970@kernel.org> In-Reply-To: References: <169849758243.1357961.4105003693126485611.stgit@mhiramat.roam.corp.google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > > > > > 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 -- Masami Hiramatsu (Google)