RE: [PATCH v9 04/12] perf/x86/intel/pt: add new capability for Intel PT

[Kang, Luwei]

> > On Tue, May 22, 2018 at 12:52:07PM +0800, Luwei Kang wrote:
> > > CPUID(EAX=14H,ECX=0):EBX[bit 3] = 1 indicates support of output to
> > > Trace Transport subsystem.
> > > MSR IA32_RTIT_CTL.FabricEn[bit 6] is reserved if CPUID.(EAX=14H,
> > > ECX=0):ECX[bit 3] = 0.
> >
> > This should instead say:
> >
> > This adds support for "output to Trace Transport subsystem" capability
> > of Intel PT, as documented in IA SDM Chapter 36.x.y.z. It means that
> > PT can output its trace to an MMIO address range rather than system
> > memory buffer.
> 
> The $subject also needs attention.

A little don't understand. What is "$subject" mean?

Thanks,
Luwei Kang