On 08/04/2010 12:34 PM, Pawel Osciak wrote:
Richard Röjfors<richard.rojfors@xxxxxxxxxxxxxx> wrote:
On 08/04/2010 11:50 AM, Pawel Osciak wrote:
How do you propose to allocate the buffers? They need to be contiguous
and using uncached memory gave really bad performance.
829440 bytes is a quite a lot and one can't reliably depend on kmalloc
to be able to allocate such big chunks of contiguous memory. Were you
testing this on a freshly rebooted system?
The systems have been running for a while, but not days.
I don't see why would dma_alloc_coherent work better than kmalloc?
In principle it wouldn't. It's just it's much less intensively used and
allocates from a special area. Not really a bullet-proof solution either
though, I agree.
So how do we move forward? I would like to see this kind of patch go in, it
obviously makes our video driver useful.
I could change and verify the patch using dma_alloc_noncoherent instead of
kmalloc. It would have the same "limitations" as todays' uncached buffers.
--Richard
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
