Re: [Patch v4 1/3] lib: Restrict cpumask_local_spread to houskeeping CPUs

[Andrew Morton]

On Mon, 29 Jun 2020 12:11:25 -0400 Nitesh Narayan Lal <nitesh@xxxxxxxxxx> wrote:

> 
> On 6/25/20 6:34 PM, Nitesh Narayan Lal wrote:
> > From: Alex Belits <abelits@xxxxxxxxxxx>
> >
> > The current implementation of cpumask_local_spread() does not respect the
> > isolated CPUs, i.e., even if a CPU has been isolated for Real-Time task,
> > it will return it to the caller for pinning of its IRQ threads. Having
> > these unwanted IRQ threads on an isolated CPU adds up to a latency
> > overhead.
> >
> > Restrict the CPUs that are returned for spreading IRQs only to the
> > available housekeeping CPUs.
> >
> > Signed-off-by: Alex Belits <abelits@xxxxxxxxxxx>
> > Signed-off-by: Nitesh Narayan Lal <nitesh@xxxxxxxxxx>
> 
> Hi Peter,
> 
> I just realized that Yuqi jin's patch [1] that modifies cpumask_local_spread is
> lying in linux-next.
> Should I do a re-post by re-basing the patches on the top of linux-next?
> 
> [1]
> https://lore.kernel.org/lkml/1582768688-2314-1-git-send-email-zhangshaokun@xxxxxxxxxxxxx/

This patch has had some review difficulties and has been pending for
quite some time.  I suggest you base your work on mainline and that we
ask Yuqi jin to rebase on that, if I don't feel confident doing it,