On Thu, Nov 12, 2015 at 11:16:06PM +0100, Steinar H. Gunderson wrote: >> You're right; I got the two patch sets mixed up. Considering that it >> was written a couple of years ago, you'll probably have to do some work >> to get it to apply to the current kernel. Let me know if you need any >> help. > There were some minor rejects, thankfully nothing big. I'll see if I can > actually get it to do anything useful, too. :-) Interesting. I hacked libusb to get the fd. Then I did USBDEVFS_ALLOC_MEMORY, which succeeded (well, as soon as I filled mem.size before calling), then mmap on it as described (which also succeeded), and everything _works_, but I don't think it's actually using zerocopy, because I still see copy_user_enhanced_fast_string() using a lot of CPU (with libusb_handle_events() in the call stack). I guess I should either add some debug printks or else see if there's anything in the snooping that can help me track it down. /* 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
