How to mount usb2 devices

[Bernd Walter]

On Sun, Dec 26, 2004 at 10:43:37PM -0800, Julian Elischer wrote:
> Bernd Walter wrote:
> >On Sat, Dec 25, 2004 at 10:34:39PM -0800, Julian Elischer wrote:
> >>for example Ugen devices can be sped up by an order of magnitude
> >>with a simple set of changes. (that I will commit when I clean
> >>them up) I have to guess that the Umass driver may have similar
> >>performance problems.
> >
> >
> >So you can speed up ugen devices - sounds interesting.
> >What is the basic idea behind?
> ehci allows only 4000 interrupts per second.
> ugen packages data in 1024 byte chunks and does one per interrupt.
> Previously it allowed only 1000 interrupts per second, limiting you to
> 1MB/sec.. Now you can get 4MB/sec.

Ah this old story.
I didn't know that ugen reduces userland requests too low.
Well yes - it should be raised - maybe only for high speed devices.

What about umass, doesn't umass run the whole CAM request in one go?
CAM reuqests should be big enough unless the underlying filesystem
requests single sectors.
The dd test should have issued slightly bigger (cam/umass overhead)
requests as 64k and 128k.

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd at bwct.de                                  info at bwct.de