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]
Date:   Wed, 20 Dec 2017 09:31:15 +0100
From:   Peter Zijlstra <>
To:     Viresh Kumar <>
Cc:     Rafael Wysocki <>, Ingo Molnar <>,,
        Vincent Guittot <>,,,,,,,
Subject: Re: [PATCH 2/4] sched: cpufreq: Keep track of cpufreq utilization
 update flags

On Wed, Dec 20, 2017 at 09:34:46AM +0530, Viresh Kumar wrote:
> On 19-12-17, 20:25, Peter Zijlstra wrote:
> > Yeah, not happy about this either; we had code that did the right thing
> > without this extra tracking I think.
> Sure, but how do you suggest we fix the problems we are facing with
> the current design? Patrick had a completely different proposal for
> solving those problems, which I didn't like very much. This patchset
> replaced these patches from Patrick:

Please use the normal link format:$MSGID

Then I can find them without having to resort to a frigging browser

I'll try and dig through the email I have.

> > Also, we can look at the rq state if we want to, we don't need to
> > duplicate that state.
> Well that also looks fine to me, and that would mean this:
> - We remove SCHED_CPUFREQ_RT and SCHED_CPUFREQ_DL flags, but still
>   call the utilization callbacks from RT and DL classes.

Didn't juri have patches to make DL do something sane? But yes, I think
those flags are part of the problem.

> - From the utilization handler, we check runqueues of all three sched
>   classes to see if they have some work pending (this can be done
>   smartly by checking only RT first and skipping other checks if RT
>   has some work).

No that's wrong. DL should provide a minimum required based on existing
reservations, we can add the expected CFS average on top and request

And for RT all we need to know is if current is of that class, otherwise
we don't care.

Powered by blists - more mailing lists