From: "Rafael J. Wysocki" <rafael@kernel.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Linux PM <linux-pm@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Zhou Ti (x2019cwm)" <x2019cwm@stfx.ca>
Subject: Re: [PATCH v1 0/5] cpuidle: Take possible negative "sleep length" values into account
Date: Wed, 7 Apr 2021 19:24:39 +0200 [thread overview]
Message-ID: <CAJZ5v0iMpOtNdnAvx3fRP-wNz4OBG9ZyDXVG0KnHDdGz2U4ipA@mail.gmail.com> (raw)
In-Reply-To: <2764850.e9J7NaK4W3@kreacher>
On Mon, Mar 29, 2021 at 8:38 PM Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
>
> Hi All,
>
> As follows from the discussion triggered by the patch at
>
> https://lore.kernel.org/lkml/20210311123708.23501-2-frederic@kernel.org/
>
> the cpuidle governors using tick_nohz_get_sleep_length() assume it to always
> return positive values which is not correct in general.
>
> To address this issues, first document the fact that negative values can
> be returned by tick_nohz_get_sleep_length() (patch [1/5]). Then, in
> preparation for more substantial changes, change the data type of two
> fields in struct cpuidle_state to s64 so they can be used in computations
> involving negative numbers safely (patch [2/5]).
>
> Next, adjust the teo governor a bit so that negative "sleep length" values
> are counted like zero by it (patch [3/5]) and modify it so as to avoid
> mishandling negative "sleep length" values (patch [4/5]).
>
> Finally, make the menu governor take negative "sleep length" values into
> account properly (patch [5/5]).
>
> Please see the changelogs of the patches for details.
Given no objections or concerns regarding this lot, let me queue it up.
Thanks!
prev parent reply other threads:[~2021-04-07 17:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-29 18:12 [PATCH v1 0/5] cpuidle: Take possible negative "sleep length" values into account Rafael J. Wysocki
2021-03-29 18:13 ` [PATCH v1 1/5] tick/nohz: Improve tick_nohz_get_next_hrtimer() kerneldoc Rafael J. Wysocki
2021-03-29 18:15 ` [PATCH v1 2/5] cpuidle: Use s64 as exit_latency_ns and target_residency_ns data type Rafael J. Wysocki
2021-03-29 18:19 ` [PATCH v1 3/5] cpuidle: teo: Adjust handling of very short idle times Rafael J. Wysocki
2021-03-29 18:21 ` [PATCH v1 4/5] cpuidle: teo: Take negative "sleep length" values into account Rafael J. Wysocki
2021-03-29 18:37 ` [PATCH v1 5/5] cpuidle: menu: " Rafael J. Wysocki
2021-03-30 1:59 ` Zhou Ti (x2019cwm)
2021-03-30 14:47 ` Rafael J. Wysocki
2021-04-07 17:24 ` Rafael J. Wysocki [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAJZ5v0iMpOtNdnAvx3fRP-wNz4OBG9ZyDXVG0KnHDdGz2U4ipA@mail.gmail.com \
--to=rafael@kernel.org \
--cc=frederic@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=rjw@rjwysocki.net \
--cc=tglx@linutronix.de \
--cc=x2019cwm@stfx.ca \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).