Re: [tip:perf/core] perf/x86/intel: Add {rd,wr}lbr_{to,from} wrappers

From: Peter Zijlstra
Date: Wed Jun 29 2016 - 15:34:35 EST


On Mon, Jun 27, 2016 at 05:56:02AM -0700, tip-bot for Peter Zijlstra wrote:
> +static inline u64 rdlbr_from(unsigned int idx)
> +{
> + u64 val;
> +
> + rdmsrl(x86_pmu.lbr_from + idx, val);
> +
> + return lbr_from_signext_quirk_rd(val);
> +}
> +
> +static inline u64 rdlbr_to(unsigned int idx)
> +{
> + u64 val;
> +
> + rdmsrl(x86_pmu.lbr_from + idx, val);

Things work loads better when we use:

rdmsrl(x86_pmu.lbr_to + idx, val);

:-/

> +
> return val;
> }