Re: [PATCH v4 4/4] perf report: Documentation average IPC and IPC coverage

[Jin, Yao]

On 11/29/2018 9:27 PM, Ingo Molnar wrote:
> * Jin Yao <yao.jin@xxxxxxxxxxxxxxx> wrote:
>
> > Add explanations for new columns "IPC" and "IPC coverage" in perf
> > documentation.
> >
> > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > ---
> >   tools/perf/Documentation/perf-report.txt | 8 ++++++++
> >   1 file changed, 8 insertions(+)
> >
> > diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
> > index 474a494..e5a32f3 100644
> > --- a/tools/perf/Documentation/perf-report.txt
> > +++ b/tools/perf/Documentation/perf-report.txt
> > @@ -126,6 +126,14 @@ OPTIONS
> >   	And default sort keys are changed to comm, dso_from, symbol_from, dso_to
> >   	and symbol_to, see '--branch-stack'.
> >   
> > +	When the sort key symbol is specified, columns "IPC" and "IPC Coverage"
> > +	are enabled automatically. Column "IPC" reports the average IPC per function
> > +	and column "IPC coverage" reports the percentage of instructions with
> > +	sampled IPC in this function. IPC means Instruction Per Cycle. If it's low,
> > +	it indicates there may be performance bottleneck when the function is
> > +	executed, such as, memory access bottleneck. If a function has high overhead
> > +	and low IPC, it's worth further analysis for performance optimization.
>
> Thank you for adding this!
>
> Just a few small nits:
>
> s/may be performance bottleneck
>   /may be a performance bottleneck
>
> s/such as, memory access bottleneck
>   /such as a memory access bottleneck
>
> s/it's worth further analysis for performance optimization.
>   /it's worth further analyzing it to optimize its performance.
>
> ?
>
> Other than that:
>
> Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>
>
> 	Ingo

Thanks Ingo!

I will add these fixes in v5.

Thanks
Jin Yao