There is no agreed-upon definition of spin_unlock_wait()'s semantics, and it appears that all callers could do just as well with a lock/unlock pair. This commit therefore replaces the spin_unlock_wait() call in do_task_dead() with spin_lock() followed immediately by spin_unlock(). This should be safe from a performance perspective because the lock is this tasks ->pi_lock, and this is called only after the task exits. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Cc: Andrea Parri <parri.andrea@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> --- kernel/sched/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index e91138fcde86..6dea3d9728c8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3461,7 +3461,8 @@ void __noreturn do_task_dead(void) * is held by try_to_wake_up() */ smp_mb(); - raw_spin_unlock_wait(¤t->pi_lock); + raw_spin_lock(¤t->pi_lock); + raw_spin_unlock(¤t->pi_lock); /* Causes final put_task_struct in finish_task_switch(): */ __set_current_state(TASK_DEAD); -- 2.5.2