Re: [PATCH] affine kernel threads to specified cpumask

From: Marcelo Tosatti
Date: Tue Mar 24 2020 - 07:39:04 EST


On Mon, Mar 23, 2020 at 09:31:59PM +0100, Thomas Gleixner wrote:
> Chris,
>
> Chris Friesen <chris.friesen@xxxxxxxxxxxxx> writes:
> > On 3/23/2020 10:22 AM, Thomas Gleixner wrote:
> >> Marcelo Tosatti <mtosatti@xxxxxxxxxx> writes:
> >>> This allows CPU isolation (that is not allowing certain threads
> >>> to execute on certain CPUs) without using the isolcpus= parameter,
> >>> making it possible to enable load balancing on such CPUs
> >>> during runtime.
> >>
> >> I'm surely missing some background information, but that sentence does
> >> not make any sense to me.
> >
> > The idea is to affine general kernel threads to specific "housekeeping"
> > CPUs, while still allowing load balancing of tasks.
> >
> > The isolcpus= boot parameter would prevent kernel threads from running
> > on the isolated CPUs, but it disables load balancing on the isolated CPUs.
>
> So why can't we just have a isolcpus mode which allows that instead of
> adding more command line options which are slightly different?
>
> We just added some magic for managed interrupts to isolcpus, which is
> surely interesting for your scenario as well...
>
> Thanks,
>
> tglx

Hi Thomas, Chris,

Works for me, will adjust and resend.