[PATCH] cpuset fork locking fix

Move the cpuset_fork() call below the write_unlock_irq call in
kernel/fork.c copy_process().

Since the cpuset-dual-semaphore-locking-overhaul.patch, the cpuset_fork()
routine acquires task_lock(), so cannot be called while holding the
tasklist_lock for write.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index d0d49879ab7c..fb8572a42297 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1124,8 +1124,6 @@ static task_t *copy_process(unsigned long clone_flags,
         if (unlikely(p->ptrace & PT_PTRACED))
                 __ptrace_link(p, current->parent);
 
-        cpuset_fork(p);
-
         attach_pid(p, PIDTYPE_PID, p->pid);
         attach_pid(p, PIDTYPE_TGID, p->tgid);
         if (thread_group_leader(p)) {
@@ -1142,6 +1140,7 @@ static task_t *copy_process(unsigned long clone_flags,
         total_forks++;
         write_unlock_irq(&tasklist_lock);
         proc_fork_connector(p);
+        cpuset_fork(p);
         retval = 0;
 
 fork_out: