Re: [PATCH 0/4] convert perf to local64_t

Peter Zijlstra
2010-05-26T10:11:33Z

On Wed, 2010-05-26 at 12:08 +0200, Frederic Weisbecker wrote:
> On Fri, May 21, 2010 at 03:42:05PM +0200, Peter Zijlstra wrote:
> > These patches introduce local64_t.
> >
> > Since perf_event:count is only modified cross-cpu when child-counters
> > feed back their changes on exit, and we can use a secondary variable
> > for that, we can convert perf to use local64_t instead of atomic64_t
> > and use instructions without buslock semantics.
> >
> > The local64_t implementation uses local_t for 64 bits, since local_t is
> > of type long, for 32 bit it falls back to atomic64_t. Architectures can
> > provide their own implementation as usual.
>
>
> It seems nobody disagrees with it. Can we give it a try?

I'll push it to mingo around -rc2 or so, to let the dust settle from the
current merge.