tree 6248c1e65b572f1c2b14c46848e5a18df003f60e
parent 356d6d5058c8082b9e811838ab2fa27825c947e4
author Oleg Nesterov <oleg@tv-sign.ru> 1192602443 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1192635774 -0700

exec: RT sub-thread can livelock and monopolize CPU on exec

de_thread() yields waiting for ->group_leader to be a zombie. This deadlocks
if an rt-prio execer shares the same cpu with ->group_leader. Change the code
to use ->group_exit_task/notify_count mechanics.

This patch certainly uglifies the code, perhaps someone can suggest something
better.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>