On Thu, Nov 12, 2015 at 02:42:09PM -0500, Alan Stern wrote: > You could try getting a "zerocopy" patch to work. See this thread: > > http://marc.info/?l=linux-usb&m=140431709523840&w=2 I'll have a look. But given that I do isochronous, it sounds like the patch in that thread won't work? (As I read the discussion there, at least. I don't know enough xHCI details to understand exactly why a memory mapping is needed for isochronous but not for bulk transfers.) There's always the other patch set that was pointed to (http://marc.info/?l=linux-usb&m=138046339714340&w=2), which sounds more promising. As an aside, my data is eventually going over in GPU memory, so there's bound to be even more copies. However, given the amount of data and the limited amount of memory bandwidth in my system, the fewer I can have, the better. /* 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
