Re: [PATCH v3 10/11] perf tools report: Implement browsing of individual samples

Jiri Olsa
2019-03-04T14:49:01Z

On Thu, Feb 28, 2019 at 10:35:49AM -0800, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> Now report can show whole time periods with perf script,
> but the user still has to find individual samples of interest
> manually.
>
> It would be expensive and complicated to search for the
> right samples in the whole perf file. Typically users
> only need to look at a small number of samples for useful
> analysis.
>
> Also the full scripts tend to show samples of all CPUs and all
> threads mixed up, which can be very confusing on larger systems.
>
> Add a new --samples option to save a small random number of samples
> per hist entry
>
> Use a reservoir sample technique to select a representatve
> number of samples.
>
> Then allow browsing the samples using perf script
> as part of the hist entry context menu. This automatically
> adds the right filters, so only the thread or cpu of the sample
> is displayed. Then we use less' search functionality
> to directly jump the to the time stamp of the selected
> sample.
>
> It uses different menus for assembler and source display.
> Assembler needs xed installed and source needs debuginfo.
>
> Currently it only supports as many samples as fit on
> the screen due to some limitations in the slang ui code.
>
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
>
> ---
> v2:
> Free names on error path
> Pass --inline and --show-*-event to child perf as needed.
> ---
> tools/perf/Documentation/perf-report.txt | 4 ++
> tools/perf/builtin-report.c | 2 +
> tools/perf/ui/browsers/Build | 1 +
> tools/perf/ui/browsers/hists.c | 47 ++++++++++++++
> tools/perf/ui/browsers/res_sample.c | 80 ++++++++++++++++++++++++
> tools/perf/ui/browsers/scripts.c | 2 +-
> tools/perf/util/hist.c | 36 +++++++++++
> tools/perf/util/hist.h | 19 ++++++
> tools/perf/util/sort.h | 8 +++
> tools/perf/util/symbol.c | 1 +
> tools/perf/util/symbol_conf.h | 1 +
> 11 files changed, 200 insertions(+), 1 deletion(-)
> create mode 100644 tools/perf/ui/browsers/res_sample.c
>
> diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
> index 546d87221ad8..f441baa794ce 100644
> --- a/tools/perf/Documentation/perf-report.txt
> +++ b/tools/perf/Documentation/perf-report.txt
> @@ -461,6 +461,10 @@ include::itrace.txt[]
> --socket-filter::
> Only report the samples on the processor socket that match with this filter
>
> +--samples=N::
> + Save N individual samples for each histogram entry to show context in perf
> + report tui browser.

maybe we could set some default value (50?)

jirka