Re: [tip:sched/core] sched/isolation: Document the isolcpus= flags

From: Ingo Molnar
Date: Fri Oct 27 2017 - 15:04:58 EST



* Frederic Weisbecker <frederic@xxxxxxxxxx> wrote:

> 2017-10-27 20:21 UTC+02:00, Ingo Molnar <mingo@xxxxxxxxxx>:
> >
> > * Frederic Weisbecker <frederic@xxxxxxxxxx> wrote:
> >
> >> 2017-10-27 19:06 UTC+02:00, Ingo Molnar <mingo@xxxxxxxxxx>:
> >> >
> >> > * Frederic Weisbecker <frederic@xxxxxxxxxx> wrote:
> >> >
> >> >> 2017-10-27 15:58 UTC+02:00, Peter Zijlstra <peterz@xxxxxxxxxxxxx>:
> >> >> > On Fri, Oct 27, 2017 at 05:06:25AM -0700, tip-bot for Frederic
> >> >> > Weisbecker
> >> >> > wrote:
> >> >> >> + isolcpus= [KNL,SMP] Isolate a given set of CPUs from disturbance.
> >> >> >> + Format: [flag-list,]<cpu-list>
> >> >> >> +
> >> >> >> + Specify one or more CPUs to isolate from disturbances
> >> >> >> + specified in the flag list (default: domain):
> >> >> >> +
> >> >> >> + nohz
> >> >> >> + Disable the tick when a single task runs.
> >> >> >> + domain
> >> >> >> + Isolate from the general SMP balancing and scheduling
> >> >> >> + algorithms. This option is the preferred way to isolate
> >> >> >> + CPUs from tasks.
> >> >> >
> >> >> > I _strongly_ object to this statement, isolcpus is _not_ the
> >> >> > preferred
> >> >> > way, cpusets are.
> >> >> >
> >> >> > And yes, while cpusets suffers some problems, we _should_ really fix
> >> >> > those and not promote this piece of shit isolcpus crap.
> >> >>
> >> >> I definitely agree with that so your position is a relief :-) This
> >> >> patch only indented the existing parameter documentation so fixing its
> >> >> content was beyond its scope. I'll send a patch to correct the text.
> >> >
> >> > Since it was the last commit in tip:sched/core that was pushed out just
> >> > hours ago
> >> > I zapped that last commit, please send an updated patch which we can
> >> > apply
> >> > and get
> >> > a clean series.
> >> >
> >> > Thanks,
> >>
> >> Note the issue was there before that patch. But nevermind I'll resend
> >> an updated version of the patch.
> >
> > Yeah - so we get a single 'improve documentation' commit.
>
> Ah ok I see. No problem I'll resend.

Thanks!

Ingo