On Sun, Sep 29, 2013 at 7:51 PM, Markus Rechberger <mrechberger@xxxxxxxxx> wrote: > > I agree, but here not only small buffers are the problem, also latency. > > I will send another patch version which overrides the SG transfer once > a preallocated buffer is submitted. The current patch will only use > the pre-allocated buffers if the buffer size is smaller than 15-16k. If you put much attention to performance & latency, I am wondering why you don't write a kernel mode usb driver to fix your problem? With usbfs and user mode driver, both performance and latency won't be very good: - URB can only be submitted in process context with context switch cost - URB complete is notified by signal, which might introduce much latency With one kernel mode driver, you can get better performance/latency much easily. Thanks, -- Ming Lei -- 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
