Re: [PATCH V2 13/23] perf/x86/intel/lbr: Factor out intel_pmu_store_lbr

[Peter Zijlstra]

On Fri, Jun 26, 2020 at 11:20:10AM -0700, kan.li...@linux.intel.com wrote:
> -static inline u64 rdlbr_from(unsigned int idx)
> +static inline u64 rdlbr_from(unsigned int idx, struct lbr_entry *lbr)
>  {
>       u64 val;
>  
> +     if (lbr)
> +             return lbr->from;
> +
>       rdmsrl(x86_pmu.lbr_from + idx, val);
>  
>       return lbr_from_signext_quirk_rd(val);
>  }
>  
> -static inline u64 rdlbr_to(unsigned int idx)
> +static inline u64 rdlbr_to(unsigned int idx, struct lbr_entry *lbr)
>  {
>       u64 val;
>  
> +     if (lbr)
> +             return lbr->to;
> +
>       rdmsrl(x86_pmu.lbr_to + idx, val);
>  
>       return val;
>  }
>  
> -static inline u64 rdlbr_info(unsigned int idx)
> +static inline u64 rdlbr_info(unsigned int idx, struct lbr_entry *lbr)
>  {
>       u64 val;
>  
> +     if (lbr)
> +             return lbr->info;
> +
>       rdmsrl(x86_pmu.lbr_info + idx, val);
>  
>       return val;

These should probably be __always_inline, just to make sure the compiler
doesn't do anything stupid.