On Mon, Feb 15, 2010 at 06:45:55AM -0800, Bernie Thompson wrote:

Add functions to pre-allocate and free usb bulk urbs for core render path.

Udlfb currently allocates a single urb, guarded by a mutex, that is a key
bottleneck. Because udlfb sends so much data, preallocation is most efficient.

I'm not going to reject this patch, but are you sure about this being
needed?  The code path for creating a new urb is very tiny, just a
memory allocation.  Is that really noticable in any benchmarks or cpu
usage that you have found?

curious,

greg k-h