Re: mplayer + heavy io: why ionice doesn't help?

From: Xavier Bestel
Date: Tue Aug 22 2006 - 13:35:01 EST


Le mardi 22 août 2006 à 18:26 +0200, Denis Vlasenko a écrit :

> > I think the problem is also due to mplayer's faulty design. It should
> > be multithreaded and use RT threads for the time sensitive work, like
> > all professional AV applications and many other consumer players do.
>
> RT - yes, multithreaded - unsure. Witness how squid manages to
> serve hundreds of simultaneous streams using just a single process.
>
> Multithreading seems cool on the first glance and it is easier to code
> than clever O_NONBLOCK/select/poll/etc stuff. However,
> on single-CPU boxes, which are still a majority, multithreading
> just incurs context switching penalty. It cannot magically
> make CPU do more work in a unit of time.

The problem with mplayer is latency more than throughput, and for that
multithreading is king. Squid can get away with a 100ms delay between
two packets, mplayer can't.

Xav

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