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

[Liang, Kan]

On 6/22/2020 2:49 PM, Cyrill Gorcunov wrote:
> On Fri, Jun 19, 2020 at 07:04:09AM -0700, kan.liang@xxxxxxxxxxxxxxx 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