linux-kernel - Re: [PATCH] cpufreq: schedutil: force frequency update when limits change

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: <20200626021428.tnecyy3wt42slvik@vireshk-i7>
Date:   Fri, 26 Jun 2020 07:44:28 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Wei Wang <wvw@...gle.com>
Cc:     Wei Wang <wei.vince.wang@...il.com>, dsmythies@...us.net,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        "Joel Fernandes (Google)" <joel@...lfernandes.org>,
        Linux PM list <linux-pm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] cpufreq: schedutil: force frequency update when limits
 change

On 25-06-20, 13:47, Wei Wang wrote:
> On Thu, Jun 25, 2020 at 3:23 AM Viresh Kumar <viresh.kumar@...aro.org> wrote:
> > I am sorry but I am not fully sure of what the problem is. Can you
> > describe that by giving an example with some random frequency, and
> > tell the expected and actual behavior ?
> >
> The problem is sugov thought next_freq already updated (but actually
> skipped by the rate limit thing) and all following updates will be
> skipped.

I am sorry, can you please give a detailed example with existing
frequency and limits, then the limits changed to new values, then what
exactly happens ?

> Actually this is specifically for Android common kernel 4.19's issue
> which has sugov_up_down_rate_limit in sugov_update_next_freq, let's
> continue discussion there.

If it is a mainline problem, we will surely get it fixed here. Just
that I am not able to understand the problem yet. Sorry about that.

-- 
viresh