[pulseaudio-discuss] [PATCH 4/6] tests: Rename voltest to volume-test

[Wang Xingchao]

2011/10/29 Maarten Bosmans <mkbosmans at gmail.com>:
> 2011/10/29 Wang Xingchao <wangxingchao2011 at gmail.com>:
>> 2011/10/29 Maarten Bosmans <mkbosmans at gmail.com>:
>>> ---
>>>  src/.gitignore          |   61 +++++++++++-----------
>>>  src/Makefile.am         |   10 ++--
>>>  src/tests/voltest.c     |  134 -----------------------------------------------
>>>  src/tests/volume-test.c |  134 +++++++++++++++++++++++++++++++++++++++++++++++
>>>  4 files changed, 170 insertions(+), 169 deletions(-)
>>>
>>
>> make sense for me. this tool is very useful to check soft volume
>> optimization. Only one comment about the timestamp before/after the
>> test, i am afraid it become inaccurate if system in high overload,
>> pa_rtclock_now() will think over sleep/interrupt time of current.
>
> Note that this is not the same test you used earlier from my orcify
> branch, that test is called svolume-test. This is an existing test
> that only checks calculations on the volume variables, not on how that
> volume value is applied to actual audio samples.
>
> As such, volume-test does not use pa_rtclock_now or any timing related
> functions.
>

thanks for clarification, i misunderstand it as the same tool at first
glance. :)

> In general you're right that for performance measures the wall clock
> time is not ideal. But on the other hand, performance test should
> always be done with an otherwise idle system, so definitely browsers,
> etc. closed.

yes, that's reasonable.
>In these cases the wall clock time is pretty reliable.
> That's why in some tests the standard deviation of the timing
> measurements is printed. If the wall clock time measurements are
> reasonably close together, you know that no external program is
> interfering with the measurements. Note that CPU time measurements are
> no help either when the system is otherwise loaded. The actual CPU
> time for other programs does not matter then, but you'll always see
> cache effects, so having an idle system is needed either way.
>

thanks for the info.

--xingchao