Re: [PATCH V3 01/23] perf/x86: Support outputting XMM registers

[Liang, Kan]

On 3/26/2019 9:47 AM, Thomas Gleixner wrote:
> On Tue, 26 Mar 2019, Liang, Kan wrote:
> > On 3/25/2019 8:11 PM, Thomas Gleixner wrote:
> >
> > -#define REG_RESERVED (~((1ULL << PERF_REG_X86_MAX) - 1ULL))
> > +#define REG_RESERVED	0
>
> What's the point of having this around?

I once thought it may be kept for future extension if we have more regs.
But, yes, we should remove it completely for now.

Thanks,
Kan

> >   int perf_reg_validate(u64 mask)
> >   {
> >   	if (!mask || mask & REG_RESERVED)
> >   		return -EINVAL;
>
>   mask & 0 == 0, right? So which bits are you checking here?
>
> Thanks,
>
> 	tglx