From: Jens Axboe <axboe@xxxxxxxxx>
[ Upstream commit 03941ccfda161c2680147fa5ab92aead2a79cac1 ]
All archs now support TIF_NOTIFY_SIGNAL.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/task_work.c | 30 +-----------------------------
1 file changed, 1 insertion(+), 29 deletions(-)
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -5,34 +5,6 @@
static struct callback_head work_exited; /* all we need is ->next == NULL */
-/*
- * TWA_SIGNAL signaling - use TIF_NOTIFY_SIGNAL, if available, as it's faster
- * than TIF_SIGPENDING as there's no dependency on ->sighand. The latter is
- * shared for threads, and can cause contention on sighand->lock. Even for
- * the non-threaded case TIF_NOTIFY_SIGNAL is more efficient, as no locking
- * or IRQ disabling is involved for notification (or running) purposes.
- */
-static void task_work_notify_signal(struct task_struct *task)
-{
-#if defined(TIF_NOTIFY_SIGNAL)
- set_notify_signal(task);
-#else
- unsigned long flags;
-
- /*
- * Only grab the sighand lock if we don't already have some
- * task_work pending. This pairs with the smp_store_mb()
- * in get_signal(), see comment there.
- */
- if (!(READ_ONCE(task->jobctl) & JOBCTL_TASK_WORK) &&
- lock_task_sighand(task, &flags)) {
- task->jobctl |= JOBCTL_TASK_WORK;
- signal_wake_up(task, 0);
- unlock_task_sighand(task, &flags);
- }
-#endif
-}
-
/**
* task_work_add - ask the @task to execute @work->func()
* @task: the task which should run the callback
@@ -76,7 +48,7 @@ int task_work_add(struct task_struct *ta
set_notify_resume(task);
break;
case TWA_SIGNAL:
- task_work_notify_signal(task);
+ set_notify_signal(task);
break;
default:
WARN_ON_ONCE(1);
