On Mon, Nov 16, 2015 at 08:03:12PM +0100, Steinar H. Gunderson wrote: > The original use case: DVB capture on embedded devices. > > My use case: USB3 uncompressed HD video capture (from multiple cards). > > Both of these hit (beyond the speed boost from zerocopy) the problem that > as time goes by, memory gets more fragmented and usbfs fails allocation. > Allocating memory up-front solves that.
As said I think you should just use get_user_pages() on user memory, and bounce buffer if it doesn't fit the DMA mask. Thіs also allows the user to use hugetlbs if they need large contiguous allocations for performance reasons. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
