Re: [PATCH 6/9] perf report: Support instruction latency

[Liang, Kan]

On 2/5/2021 6:08 AM, Namhyung Kim wrote:
> On Wed, Feb 3, 2021 at 5:14 AM <kan.liang@xxxxxxxxxxxxxxx> wrote:
> > From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
> >
> > The instruction latency information can be recorded on some platforms,
> > e.g., the Intel Sapphire Rapids server. With both memory latency
> > (weight) and the new instruction latency information, users can easily
> > locate the expensive load instructions, and also understand the time
> > spent in different stages. The users can optimize their applications
> > in different pipeline stages.
> >
> > The 'weight' field is shared among different architectures. Reusing the
> > 'weight' field may impacts other architectures. Add a new field to store
> > the instruction latency.
> >
> > Like the 'weight' support, introduce a 'ins_lat' for the global
> > instruction latency, and a 'local_ins_lat' for the local instruction
> > latency version.
>
> Could you please clarify the difference between the global latency
> and the local latency?

The global means the total latency.
The local means average latency, aka total / number of samples.

Thanks,
Kan