Could you test the attached singlecopy patches?

with bw_pipe,
* on UP, up to +100%.
* on SMP with busy cpus, up to +100%
* on SMP with idle cpus a performance drop due to increased cache
trashing. Probably the scheduler should keep both bw_pipe processes on
the same cpu.

I've sent patch-pgw to Linus for inclusion, since it's needed to fix the
elf coredump deadlock.

patch-kiopipe must wait until 2.5, because it changes the behaviour of
pipe_write with partial reads.

--
	Manfred