Re: [PATCH 21/21] perf/x86/intel/lbr: Support XSAVES for arch LBR read

Liang, Kan
2020-06-22T19:11:15Z

On 6/22/2020 2:49 PM, Cyrill Gorcunov wrote:
> On Fri, Jun 19, 2020 at 07:04:09AM -0700, kan.liang@linux.intel.com wrote:
> ...
>> +static void intel_pmu_arch_lbr_read_xsave(struct cpu_hw_events *cpuc)
>> +{
>> + struct x86_perf_task_context_arch_lbr_xsave *xsave = cpuc->lbr_xsave;
>> + struct arch_lbr_entry *lbr;
>> + int i;
>> +
>> + if (!xsave)
>> + goto rollback;
>
> Why not make it simplier?
>
> if (!xsave) {
> intel_pmu_arch_lbr_read(cpuc);
> return;
> }
>
> The goto and "return" statement before the "rollback" label
> looks pretty ugly. I'm sorry I didn't follow the series
> in details so if you plan to add more handlers at "rollback"
> then sure.
>

There were several handlers when I first implemented the function, but
they are removed now. I don't think I will add more handlers in the next
version.
I will remove the "rollback" label.

Thanks for pointing it out.

Kan