On Mon, Nov 16, 2015 at 07:55:45PM +0100, Christoph Hellwig wrote: >> A proposed patch has been posted >> (http://marc.info/?l=linux-usb&m=144763502829452&w=2), but I'm not >> convinced that it is the best approach. For instance, it always tries >> to get contiguous pages and so is vulnerable to memory fragmentation. > This looks totally crazy to me. What's the use case for it? 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. /* Steinar */ -- Homepage: https://www.sesse.net/ -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
