tree 6c8d313aec92310787c14b7d289f69e3e5e38711
parent 663997d417330a59a566452f52cfa04c8ffd190b
author Thomas Gleixner <tglx@linutronix.de> 1260353698 +0000
committer Ingo Molnar <mingo@elte.hu> 1260807094 +0100

sched: Use rcu in sys_sched_getscheduler/sys_sched_getparam()

read_lock(&tasklist_lock) does not protect
sys_sched_getscheduler and sys_sched_getparam() against a
concurrent update of the policy or scheduler parameters as
do_sched_setscheduler() does not take the tasklist_lock. The
accessed integers can be retrieved w/o locking and are snapshots
anyway.

Using rcu_read_lock() to protect find_task_by_vpid() and prevent
the task struct from going away is not changing the above
situation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091209100706.753790977@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>