[PATCH v3 5/6] sched/wait: Add wait_event_state()

Peter Zijlstra
2022-08-22T11:48:12Z

Allows waiting with a custom @state.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
include/linux/wait.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -931,6 +931,34 @@ extern int do_wait_intr_irq(wait_queue_h
__ret; \
})

+#define __wait_event_state(wq, condition, state) \
+ ___wait_event(wq, condition, state, 0, 0, schedule())
+
+/**
+ * wait_event_state - sleep until a condition gets true
+ * @wq_head: the waitqueue to wait on
+ * @condition: a C expression for the event to wait for
+ * @state: state to sleep in
+ *
+ * The process is put to sleep (@state) until the @condition evaluates to true
+ * or a signal is received. The @condition is checked each time the waitqueue
+ * @wq_head is woken up.
+ *
+ * wake_up() has to be called after changing any variable that could
+ * change the result of the wait condition.
+ *
+ * The function will return -ERESTARTSYS if it was interrupted by a
+ * signal and 0 if @condition evaluated to true.
+ */
+#define wait_event_state(wq_head, condition, state) \
+({ \
+ int __ret = 0; \
+ might_sleep(); \
+ if (!(condition)) \
+ __ret = __wait_event_state(wq_head, condition, state); \
+ __ret; \
+})
+
#define __wait_event_killable_timeout(wq_head, condition, timeout) \
___wait_event(wq_head, ___wait_cond_timeout(condition), \
TASK_KILLABLE, 0, timeout, \