RE: [PATCH 0/3]measure SMI cost

From: Liang, Kan
Date: Fri Mar 24 2017 - 10:14:38 EST




>
> > > > A new --smi-cost mode in perf stat is implemented to measure the
> > > > SMI cost by calculating cycles and aperf results. In practice, the
> > > > percentages of SMI cycles should be more useful than absolute value.
> > >
> > > That's only true for performance oriented analysis, but for
> > > analyzing the root cause of latencies the actual cycles are definitely
> interesting.
> >
> > perf stat also prints the absolute cycles of course (unless you do
> > --metric-only)
>
> So much for the theory. From the patch:
>
> + if (!force_metric_only)
> + metric_only = true;
>

The metric_only will be set by default in the patch. If user wants to get
the actual cycles, they can apply --no-metric-only.

Do you want me to make it clear in the changelog? Or you just don't like
that "metric_only=true" is set by default?


Thanks,
Kan