Re: profiler which does not just sum up used time


"Joe Withawk" <no@xxxxx> wrote in message
news:4784f007$0$7604$157c6196@xxxxxxxxxxxxxxxxxxxxxxxx
To conclude, on a system with only one or two CPU's (cores) a higher
priority thread will run for at most ~5 second before it will get
pre-empted. The time it will get off a CPU depends on the other threads
activity, but keeping a single core busy for such a long period (~5
seconds) will probably accumulate that much lower priority threads to
become ready, so that your thread will get pre-empted for at a complete
quantum or more.

Thanks for the details. I was aware that to prevent starvation the threads
would over time build up priority. I did however beleive that their
priority would never go above high.

http://msdn2.microsoft.com/en-us/library/ms685100(VS.85).aspx
http://msdn2.microsoft.com/en-us/library/ms684828(VS.85).aspx

An application can be set to realtime priority and according to what I
have read, this should prevent preempting entirely, but that still does
not seem to be the case.. Or perhaps it has to do with me not being able
to set a threads priority to realtime. Only the application can be
realtime.

How would you suggest that I move on now? I have an app doing rendering
and it occationally gets preempted (or so I beleive, can I test is this is
indeed the cause somehow?) and when that happens I lose a few frames. I
can not live with even a single lost frame unless the rendering is very
complex, which it is generally not. What could be a solution to this?

If you have already thoroughly debugged your application and you trust it
not to lockup the entire system, you could set REALTIME_PRIORITY_CLASS for
your entire process.

A better way would be to increase the buffer so it doesn't
overflow/underflow during a short delay.


.

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