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Re: Audio mixing in kernel ?
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Re: Audio mixing in kernel ?


  • Subject: Re: Audio mixing in kernel ?
  • From: Matthew Xavier Mora <email@hidden>
  • Date: Tue, 23 Jun 2009 07:08:17 -0700

The mixing code is run in the kernel during the audio io trap call. The audio trap call explicitly saves and restores the fp register because it knows that it will be dealing with floats. The kernel does not save and restore fp registers when doing a context switch from user to kernel. If the code getting called in the kernel touches those registers it must save and store them.

Matt

Sent from my iPhone

On Jun 23, 2009, at 4:25 AM, Stéphane Letz <email@hidden> wrote:

Hi,

My understanding of CoreAudio layering is that audio mixing (when several applications play an audio stream) is actually done in kernel mode.

It that correct?

So does it mean that OSX actually save/restore the processor FPU context between kernel thread switches?

Thanks

Stephane Letz
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References: 
 >Audio mixing in kernel ? (From: Stéphane Letz <email@hidden>)

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