This suspends and resumes all uprof timers and counters except while dealing
with picking, so as to give more focused statistics.
Be aware that there are still some issues with this profile option since
there are a few special case counters and timers that shouldn't be
suspended; noteably the frame counters are incorrect so the per frame stats
can't be trusted.
As we have for debugging, this adds the ability to control profiling flags
either via the command line or an environment variable.
The first option added is CLUTTER_PROFILE=disable-report
This also changes the reporting to be opt-out so you don't need to export
CLUTTER_PROFILE_OUTPUT_REPORT=1 to see a report but you can use
CLUTTER_PROFILE=disable-report to disable it if desired.
UProf is a small library that aims to help applications/libraries provide
domain specific reports about performance. It currently provides high
precision timer primitives (rdtsc on x86) and simple counters, the ability
to link statistics between optional components at runtime and makes report
generation easy.
This adds initial accounting for:
- Total mainloop time
- Painting
- Picking
- Layouting
- Idle time
The timing done by uprof is of wall clock time. It's not based on stochastic
samples we simply sample a counter at the start and end. When dealing with
the complexities of GPU drivers and with various kinds of IO this form of
profiling can be quite enlightening as it will be able to represent where
your application is blocking unlike tools such as sysprof.
To enable uprof accounting you must configure Clutter with --enable-profile
and have uprof-0.2 installed from git://git.moblin.org/uprof
If you want to see a report of statistics when Clutter applications exit you
should export CLUTTER_PROFILE_OUTPUT_REPORT=1 before running them.
Just a final word of caution; this stuff is new and the manual nature of
adding uprof instrumentation means it is prone to some errors when modifying
code. This just means that when you question strange results don't rule out
a mistake in the instrumentation. Obviously though we hope the benfits out
weigh e.g. by focusing on very key stats and by having automatic reporting.
