dump problems

[Danny Braniss]

to recap:
	dump will get stuck/deadlock.

found the problem, but no solution in sight :-(
dump creates 3 processess and syncs with them via kill(2) - don't want
to go into the merrits of this - and sometimes:
	- the signal is received even if it's blocked.
	- the signal is not received.
- it happens mainly on > 2way multicore hosts.

all this seems to be a problem in the kernel.

need some insight please!

thanks,
	danny
PS: sorry for the shortness of the message, anything else will get me to
start %$#@! dump, specially tape.c.