linux-kernel - Re: [RFT][PATCH v4 3/7] sched: idle: Do not stop the tick before cpuidle_idle

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJZ5v0hGsXV8HTKC8iS0pD6VLoe8pDutos7NhWPU+wid_q7Now@mail.gmail.com>
Date:   Thu, 15 Mar 2018 22:12:57 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Frederic Weisbecker <frederic@...nel.org>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Peter Zijlstra <peterz@...radead.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        Frederic Weisbecker <fweisbec@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Paul McKenney <paulmck@...ux.vnet.ibm.com>,
        Thomas Ilsche <thomas.ilsche@...dresden.de>,
        Doug Smythies <dsmythies@...us.net>,
        Rik van Riel <riel@...riel.com>,
        Aubrey Li <aubrey.li@...ux.intel.com>,
        Mike Galbraith <mgalbraith@...e.de>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [RFT][PATCH v4 3/7] sched: idle: Do not stop the tick before cpuidle_idle_call()

On Thu, Mar 15, 2018 at 9:41 PM, Rafael J. Wysocki <rafael@...nel.org> wrote:
> On Thu, Mar 15, 2018 at 7:19 PM, Frederic Weisbecker
> <frederic@...nel.org> wrote:
>> On Mon, Mar 12, 2018 at 10:53:25AM +0100, Rafael J. Wysocki wrote:
>>> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
>>>
>>> Make cpuidle_idle_call() decide whether or not to stop the tick.
>>>
>>> First, the cpuidle_enter_s2idle() path deals with the tick (and with
>>> the entire timekeeping for that matter) by itself and it doesn't need
>>> the tick to be stopped beforehand.
>>
>> Not sure you meant timekeeping either :)
>
> Yeah, I meant nohz.

Well, not really. :-)

It is the entire timekeeping this time, as it can be suspended
entirely in that code path.