> it turns out that _strayintr is taking up nearly all the time.

Or maybe it isn't.  Taking up nearly all the cpu time isn't the
same as taking up nearly all the time.  You can use time(1) while
reading usb disk to see if cpu is really the bottleneck, or if
in fact your machine is spending most of its time waiting for
a usb interrupt.  If the machine is mostly idle, profiling clock
ticks should usually find it sitting at the HLT instruction which
happens to be couple of bytes before _strayintr.


Reply via email to