linux futex deadlock

[Andrew Pantyukhin]

Hello!

I've stumbled upon an easily reproducible problem, seemingly somewhere around the linux_futex.c code.

When genpuid (from port audio/linux-genpuid) is run in several copies simultaneously, all the processes but the very first one end up in states futex or nanslp. If a make linux futex calls a noop (commenting out a few body functions), the processes work fine in parallel.

You can reproduce this way:
- install linux-genpuid
- get a few mp3's, say 1.mp3, 2.mp3, 3.mp3
- run:
for i in 1 2 3;do
genpuid e4230822bede81ef71cde723db743e27 -xml -data -print rmd=2 $i.mp3 &
done

Works fine under a recent ubuntu.

Anyone interested to look at this?