From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: 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: [PATCH v1 0/5] cpuidle: Take possible negative "sleep length" values into account
Date: Mon, 29 Mar 2021 20:12:39 +0200 [thread overview]
Message-ID: <2764850.e9J7NaK4W3@kreacher> (raw)
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.
Thanks!
next reply other threads:[~2021-03-29 18:38 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-29 18:12 Rafael J. Wysocki [this message]
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 ` [PATCH v1 0/5] cpuidle: Take possible " Rafael J. Wysocki
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