There are some ways to mitigate this. See this wiki topic:
http://wiki.davincidsp.com/index.php?title=Cache_Management

Mark

________________________________
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Etienne Eccles
Sent: Tuesday, May 20, 2008 7:47 PM
To: [email protected]
Subject: Cache invalidation

Hi

I am using the IVIDENC interface to call my codec on the DSP via the 
VIDENC_process(encHandle, &inBufDesc, &outBufDesc, &inArgs, &outArgs) call. My 
input and output buffers are essentially  large frame buffers of around 1Mb 
each. I have noticed that the interface assumes that these buffers are going to 
be accessed via the cache and so does a lot of cache invalidation each time 
which adds a significant overhead to the call (3-4% DSP load). Since I am only 
accessing these buffers via DMA and never directly they will never be brought 
into the cache, so this seems like a waste of DSP load.
Is there any way to avoid this overhead by instructing the interface not to 
clear out the cache?

Regards,

Etienne Eccles

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