Hi, On Tue, Jan 28, 2003 at 09:11:19PM +0000, Andrew Suffield wrote: > On Tue, Jan 28, 2003 at 08:12:17AM +0100, Gabucino wrote: > > > or do you just have no understanding of how scheduling works and what the > > > CPU% value means? > > After two years in media players, I thought I know what I am talking > > about. > > Think again, you clearly don't (and where, exactly, does the design > and analysis of process scheduling code fit in to "media > players"?). Did you actually *read* my explanation of why your > "benchmark" was fundamentally flawed? Did you have trouble > understanding some parts of it? I hate to say it, Andrew, but I must say that looking at the CPU load of a single process on an otherwise idle system /does/ make sense in some situations. And this is one of those cases. You see, if you're playing audio or video, you'll inevitably have a timer somewhere that ticks if it's time to output the next frame, be it audio or video. Now, if the processing code only needs a fraction of the time interval provided by the timer to complete its job, then the CPU load you see will be low, as it will be waiting for the timer to tick the rest of the time. A CPU load pegged at 100% means that the process doesn't finish its work during the interval soon enough to allow it to sleep in the timer at all. So assuming a process operating on a monotonic timer, then yes, looking at the CPU load does make sense. (Sorry). You were assuming that a media player needs all the CPU it can get by definition. And there lies the error, IMHO. Cheers, Emile. -- E-Advies / Emile van Bergen | emile@e-advies.info tel. +31 (0)70 3906153 | http://www.e-advies.info
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