[PATCH] Drop tasklist lock in do_sched_setscheduler
There is no need to hold tasklist_lock across the setscheduler call, when
we pin the task structure with get_task_struct(). Interrupts are disabled
in setscheduler anyway and the permission checks do not need interrupts
disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sched.c b/kernel/sched.c
index 08431f0..7a30add 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4091,8 +4091,10 @@
read_unlock_irq(&tasklist_lock);
return -ESRCH;
}
- retval = sched_setscheduler(p, policy, &lparam);
+ get_task_struct(p);
read_unlock_irq(&tasklist_lock);
+ retval = sched_setscheduler(p, policy, &lparam);
+ put_task_struct(p);
return retval;
}