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 <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Will Deacon <[email protected]> Cc: Alan Stern <[email protected]> Cc: Andrea Parri <[email protected]> Cc: Linus Torvalds <[email protected]> --- kernel/exit.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/exit.c b/kernel/exit.c index 516acdb0e0ec..6d19c9090d43 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -832,7 +832,8 @@ 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", -- 2.5.2
