linux-kernel - Re: [PATCH 1/2] sched/uclamp: Add a new sysctl to control RT default boost value

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20200420205210.7217651c@oasis.local.home>
Date:   Mon, 20 Apr 2020 20:52:10 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Qais Yousef <qais.yousef@....com>
Cc:     Dietmar Eggemann <dietmar.eggemann@....com>,
        Patrick Bellasi <patrick.bellasi@...bug.net>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Jonathan Corbet <corbet@....net>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        Luis Chamberlain <mcgrof@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        Iurii Zaikin <yzaikin@...gle.com>,
        Quentin Perret <qperret@...gle.com>,
        Valentin Schneider <valentin.schneider@....com>,
        Pavan Kondeti <pkondeti@...eaurora.org>,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH 1/2] sched/uclamp: Add a new sysctl to control RT
 default boost value

On Mon, 20 Apr 2020 16:19:42 +0100
Qais Yousef <qais.yousef@....com> wrote:

> > root@...0:~# find / -name "*util_clamp*"
> > /proc/sys/kernel/sched_rt_default_util_clamp_min
> > /proc/sys/kernel/sched_util_clamp_max
> > /proc/sys/kernel/sched_util_clamp_min
> > 
> > IMHO, keeping the common 'sched_util_clamp_' would be helpful here, e.g.
> > 
> > /proc/sys/kernel/sched_util_clamp_rt_default_min  
> 
> All RT related knobs are prefixed with 'sched_rt'. I kept the 'util_clamp_min'
> coherent with the current sysctl (sched_util_clamp_min). Quentin suggested
> adding 'default' to be more obvious, so I ended up with
> 
> 	'sched_rt' + '_default' + '_util_clamp_min'.
> 
> I think this is the logical and most consistent form. Given that Patrick seems
> to be okay with the 'default' now, does this look good to you too?

There's only two files with "sched_rt" and they are tightly coupled
(they define how much an RT task may use the CPU).

My question is, is this "sched_rt_default_util_clamp_min" related in
any way to those other two files that start with "sched_rt", or is it
more related to the files that start with "sched_util_clamp"?

If the latter, then I would suggest using
"sched_util_clamp_min_rt_default", as it looks to be more related to
the "sched_util_clamp_min" than to anything else.

-- Steve