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

From: Namhyung Kim
Date: Fri Feb 05 2021 - 06:12:16 EST


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?

Thanks,
Namhyung


>
> Add new sort functions, INSTR Latency and Local INSTR Latency,
> accordingly.
>
> Add local_ins_lat to the default_mem_sort_order[].
>
> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>