Re: [PATCH v2 4/9] perf affinity: Add infrastructure to save/restore affinity

[Andi Kleen]

On Wed, Oct 23, 2019 at 11:59:11AM +0200, Jiri Olsa wrote:
> On Sun, Oct 20, 2019 at 10:51:57AM -0700, Andi Kleen wrote:
> 
> SNIP
> 
> > +}
> > diff --git a/tools/perf/util/affinity.h b/tools/perf/util/affinity.h
> > new file mode 100644
> > index 000000000000..e56148607e33
> > --- /dev/null
> > +++ b/tools/perf/util/affinity.h
> > @@ -0,0 +1,15 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +#ifndef AFFINITY_H
> > +#define AFFINITY_H 1
> > +
> > +struct affinity {
> > +	unsigned char *orig_cpus;
> > +	unsigned char *sched_cpus;
> 
> why not use cpu_set_t directly?

Because it's too small in glibc (only 1024 CPUs) and perf already 
supports more.

-andi