Re: [PATCH net-next 1/2] sched/topology: Expose sched_numa_find_closest

[Tariq Toukan]

On 7/18/2022 1:19 PM, Peter Zijlstra wrote:
> On Sun, Jul 17, 2022 at 08:23:00AM +0300, Tariq Toukan wrote:
> > This logic can help device drivers prefer some remote cpus
> > over others, according to the NUMA distance metrics.
> >
> > Reviewed-by: Gal Pressman <gal@xxxxxxxxxx>
> > Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
> > ---
> >   include/linux/sched/topology.h | 2 ++
> >   kernel/sched/topology.c        | 1 +
> >   2 files changed, 3 insertions(+)
> >
> > diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
> > index 56cffe42abbc..d467c30bdbb9 100644
> > --- a/include/linux/sched/topology.h
> > +++ b/include/linux/sched/topology.h
> > @@ -61,6 +61,8 @@ static inline int cpu_numa_flags(void)
> >   {
> >   	return SD_NUMA;
> >   }
> > +
> > +int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
> >   #endif
> >   
> >   extern int arch_asym_cpu_priority(int cpu);
> > diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
> > index 05b6c2ad90b9..688334ac4980 100644
> > --- a/kernel/sched/topology.c
> > +++ b/kernel/sched/topology.c
> > @@ -2066,6 +2066,7 @@ int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
> >   
> >   	return found;
> >   }
> > +EXPORT_SYMBOL(sched_numa_find_closest);
>
> EXPORT_SYMBOL_GPL() if anything.

I'll fix.

> Also, this thing will be subject to sched_domains, that means that if
> someone uses cpusets or other means to partition the machine, that
> effects the result.
>
> Is that what you want?

Yes, it's good enough, at least as a first phase and basic functionality.
Later we might introduce whatever enhancements we find necessary.


Thanks,
Tariq