Re: Overloads
Re: Overloads
- Subject: Re: Overloads
- From: William Stewart <email@hidden>
- Date: Mon, 24 May 2004 11:23:31 -0700
You might want to profile the code with the Shark tool
(Developer/Applications/Performance) - you can set that to detect vm
page ins, cache misses, etc... You might see something using this that
isn't actually causing an overload on a faster machine, but is
potentially problematic
Bill
On 21/05/2004, at 9:37 PM, Glenn Maynard wrote:
>
We're having reports of overloads on older machines, especially during
>
data loading.
>
>
This is hard for us to track--there's only one of us on a Mac, he's on
>
a new machine that doesn't have the problem, and we don't have access
>
(even remote) to any that do.
>
>
The code is fairly standard, as far as the IOProc is concerned: grab
>
data from some lockless FIFOs, mix them together, passing the results
>
through an AudioConverter. The mixing isn't heavily optimized, but
>
during loads, only a BGM is playing, so that isn't being stressed.
>
All decoding happens in a separate thread, which is priority boosted
>
(or the IOProc was starving during loads) but not realtime.
>
>
For reference, if anyone's bored enough to actually read code:
>
>
>
http://cvs.sf.net/viewcvs.py/stepmania/stepmania/src/arch/Sound/
>
RageSoundDriver_CA.cpp?view=markup
>
>
and an example log:
>
>
http://www.stolaf.edu/people/voss/files/info.txt
>
>
I'm hoping somebody can point out something obviously wrong that I'm
>
overlooking. If I had access to a machine that can reproduce the
>
problem,
>
I could track it down further, but currently all I can do is add logs,
>
wait until the next testing snapshot is released (1-2 weeks), and wait
>
for
>
bug reports to arrive to see the results--a slow turnaround.
>
>
(I ran some basic stats before releasing a snapshot recently, tracking
>
average time--under 1ms per IOProc buffer--but I should have tracked
>
worst-case times, or perhaps keep track of the duration of the last
>
IOProc, and log it in the overload handler, which I'll do for the
>
next snapshot.)
>
>
--
>
Glenn Maynard
>
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| References: | |
| | >Overloads (From: Glenn Maynard <email@hidden>) |