* Chenggang Qin <chenggang....@gmail.com> wrote:
> This patch set introduced a feature to analysis the samples in a specified
> time
> interval.
> After perf.data file was generated by perf record, the user could want to
> analysis a sub time interval of the whole record period.
> For some functions, the percent of its samples in a certain sub time interval
> is
> different from the percent in the total record period. Showing the scene in a
> certain time interval could allow users to more easily troubleshoot
> performance
> problems. The sample's timestamp are recorded in the perf.data file. The
> samples
> are sorted in the ordered_samples by timestamp while perf report processed
> them.
> So, it is easily to search the samples whose timestamp are in a certain time
> interval.
> We add 2 paramters --start and --end to specify the time interval.
> perf report --start xxxxx --end xxxxx
> The smallest granularity of time interval is millsecond.
> For example:
> If the whole record period of a perf.data file is 10000 to 20000, we can use
> the
> following command to analysis the samples between [15000, 16000).
> perf report --start 15000 --end 16000
> The time is the uptime, it start timing from the system starts.
>
> Cc: David Ahern <dsah...@gmail.com>
> Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
> Cc: Paul Mackerras <pau...@samba.org>
> Cc: Ingo Molnar <mi...@redhat.com>
> Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
> Cc: Arjan van de Ven <ar...@linux.intel.com>
> Cc: Namhyung Kim <namhy...@gmail.com>
> Cc: Yanmin Zhang <yanmin.zh...@intel.com>
> Cc: Wu Fengguang <fengguang...@intel.com>
> Cc: Mike Galbraith <efa...@gmx.de>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Signed-off-by: Chenggang Qin <chenggang....@taobao.com>
>
> Chenggang Qin (4):
> perf tools: add parameter 'start' & 'end' to perf report
> perf tools: relate 'start' & 'end' to perf_session
> perf tools: record min_timestamp of samples queue in ordered_samples
> perf tools: add the feature to assign analysis interval to perf
> report
>
> tools/perf/builtin-report.c | 14 ++++++++++++
> tools/perf/util/session.c | 49 +++++++++++++++++++++++++++++++++++++++++-
> tools/perf/util/session.h | 3 ++
> 3 files changed, 64 insertions(+), 2 deletions(-)
Looks useful - but right now this has to be used 'blindly', without
knowing _which_ portion of the perf.data is 'interesting'.
That problem could be resolved by allowing direct manipulation of
the start/end interval via the GTK front end: a small graph could
show the 'sample graph', with two sliders specifying the reported
interval?
Something like this, at the top of the window:
---------------------------------------------------------------
| |
| .... ..... |
| .. . ... . . |
| . ... . . . . |
| ..... .. .. .... .... .. |
| [1] [2] |
---------------------------------------------------------------
|
| Usual perf report GTK output
|
| ....
|
The 'graph' might be anything that visualizes the time axis of the
perf.data: a sample frequency visualization for example, or maybe a
simple task activity graph based on fork/exec/exit data, with some
simple time display included as well (a vertical marker every
minute/second or so).
The [1] and [2] markers demark the two sliders, which in the above
mockup example show an 'interesting' portion of the profile with a
lot of samples.
With such a solution the feature you add would be very useful
indeed, I'd even argue for the data file time-axis visualization to
be enabled by default, with the initial start/end interval covering
the whole perf.data, but the sliders being just a mouse-drag away
from being changed.
Thanks,
Ingo
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