From 8083f29349372d5b949dc022ae9a981edc89ac41 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 29 Jun 2017 12:55:21 -0700 Subject: exit: Replace spin_unlock_wait() with lock/unlock pair 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_exit() with spin_lock() followed immediately by spin_unlock(). This should be safe from a performance perspective because the lock is a per-task lock, and this is happening only at task-exit time. Signed-off-by: Paul E. McKenney Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Will Deacon Cc: Alan Stern Cc: Andrea Parri Cc: Linus Torvalds --- kernel/exit.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/exit.c b/kernel/exit.c index c5548faa9f37..abfbcf66e5c0 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -819,7 +819,8 @@ void __noreturn do_exit(long code) * Ensure that we must observe the pi_state in exit_mm() -> * mm_release() -> exit_pi_state_list(). */ - raw_spin_unlock_wait(&tsk->pi_lock); + raw_spin_lock_irq(&tsk->pi_lock); + raw_spin_unlock_irq(&tsk->pi_lock); if (unlikely(in_atomic())) { pr_info("note: %s[%d] exited with preempt_count %d\n", -- cgit v1.2.3