Hi,
I've noticed that q_to_b() function is very often followed
by uiomove() to move data to userland. Commonly keyboard
and mouse drivers do this, but also sys/kern/tty_pty.c:ptcread().

tty_pty.c:ptcwrite() also does uiomove() followed by b_to_q() once.

Would it make sense to add uio-aware versions of those
two functions (either add new q_to_u() and u_to_q()), so that
the I/O would happen directly to/from userland and
one memory-to-memory copy would be avoided ? This would primarily
have some effect for pty's, but might also save a few cycles
in the keyboard/mouse drivers.

Jaromir