RE: [PATCH 1/1] perf/x86: filter branches for PEBS event

Liang, Kan
2015-03-27T13:10:21Z

> On Thu, Mar 26, 2015 at 02:13:23PM -0400, kan.liang@intel.com wrote:
> > This patch move intel_shared_regs_constraints for branch_reg ahead of
> > intel_pebs_constraints.
>
> Why not all shared regs?

Yes, all shared regs can also be moved ahead.
The patch is named for modifying the branch filter. I didn't want to change
other codes. So I keep them unchanged.
I will do it in next version.

>
> > intel_shared_regs_constraints for branch_reg doesn't modify event->hw,
> > so it's safe to be called before intel_pebs_constraints.
> > intel_shared_regs_constraints for branch_reg also special case when it
> > returns &emptyconstraint. It put constraints for extra_reg. This patch
> > remove it. Because it will never get constraints for extra_reg if
> > return is &emptyconstraint.
>
> -ENOPARSE.
Will remove the description, since it doesn't need in next version.

Thanks,
Kan