Hello
I am helping to write a multi-media application that plays lots of
different video and audio formats.
I would like to improve the performance of the program.
I wish to be able to make a function call to start a timer, and then
later on in the program stop the timer and therefore gather information
about how long a particular routine took.
The problem I have is that between start of timer and stop of timer, the
kernel might task switch to another thread or process. I would like this
kernel task switch to automatically stop the timer, and then restart it
when I get CPU time returned. I cannot find any such API availiable
currently in the linux kernel.
Also, as an extension to this, it would be nice to know which other
tasks happened during the task switch. The reason I would like this, is
so that I can tell if the time was taken reading data off the hard disk
or instead time spent by X displaying/transfering to screen the next
video frame. If too much time is being spent doing a task like reading
from the hard disk, I would need to look into reducing the latency of
that task. This might also highlight buggy modules that take up too much
of a time slice. I have seen some task switches take 800ms away from my
audio out thread, and therefore causing underruns on the sound hardware,
that then causes glitches in the perceived audio coming from the speakers.
Also, the reason for the above requests is so that I can gather useful
performance info without having to trawl through hugh global performance
traces.
Can anyone help me?
Cheers
James
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This archive was generated by hypermail 2b29 : Tue Oct 15 2002 - 22:00:46 EST