Date: Tue, 27 May 2008 19:51:16 -0700 (PDT) From: Unga <unga888@yahoo.com> To: freebsd-stable@FreeBSD.ORG Cc: Oliver Fromme <olli@lurza.secnetix.de> Subject: Re: sched_ule performance on single CPU Message-ID: <501295.26204.qm@web57008.mail.re3.yahoo.com> In-Reply-To: <200805271219.m4RCJ7Q6038124@lurza.secnetix.de>
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--- Oliver Fromme <olli@lurza.secnetix.de> wrote:
> Unga <unga888@yahoo.com> wrote:
> > When open an pdf has two types of scenarios in
> > FreeBSD:
> > 1. When X run as a realtime-prio process, X go
> mad and
> > swallow up almost all of CPU cycles, making audio
> > hiccups.
>
> That's expected. Running the X server with rtprio
> is not
> a good idea. There's no reason to do that.
>
I disagree for this. This may most probably depends on
what priority X's clients run.
Appreciate if Chuck Swiger could enlighten us again on
what priority X run on Mac OSX? realtime or normal?
> > 2. When X run as a normal-prio process, X behaves
> well
> > and rarely gets an audible hiccup.
>
> That's good. :-)
>
> > Why X behave different under different priority
> > categories? Isn't this scheduler related?
>
> Very simple: Sometimes the X server consumes lots
> of CPU
> for a short time. If it runs with rtprio, then no
> other
> process gets a chance to execute, so your audio
> program
> will starve.
>
The audio application obviously run on realtime-prio.
So can it starve? If it starve? :)
> My recommendation is to not use rtprio or renice. I
> think
> many people who try to use them are making things
> worse.
> (In fact I think rtprio and idprio should die.)
>
Again I disagree on this. I think rtprio and idprio
are a great asset to distribute different processes to
different priority categories.
Example, I may be having the openoffice compilation
running for a day. I maybe donating my CPU time to
protein synthesis program, SETI, etc and they are
running all the time.
When I'm not compiling, I may be encoding a hi-def
footage running for 10 hours.
At the same time, I need to browse and aware what's
going on around world and listen to music also. Family
members also want to access the computer.
You want all of these activities run in one priority
category?
> > I wonder the issue I mentioned, open a pdf while
> > playback audio, is it a issue on Apple Mac OSX?
> Could
> > somebody give some light here who uses an Apple
> Mac
> > OSX on this list?
>
> OSX has a vastly different kernel, scheduler, I/O
> system,
> audio drivers and so on. It's a completely
> different
> animal.
>
Hope by improving things on FreeBSD side, FreeBSD can
call it a brother, may be a big bother, rather than an
animal :)
> Have you tried increasing the audio driver's
> buffersize?
> It probably helps to alleviate your problem. I
> think
> OSX sizes the buffer dynamically (not sure though).
>
This is something I really want to try as soon as I
get bit of time.
Kind regards
Unga
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