Commit e9a56c93 authored by Jens Axboe's avatar Jens Axboe
Browse files

futex: make the vectored futex operations available 



Rename unqueue_multiple() as futex_unqueue_multiple(), and make both
that and futex_wait_multiple_setup() available for external users. This
is in preparation for wiring up vectored waits in io_uring.

Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5177c0cb

kernel/futex/futex.h

+5 −0
Original line number Diff line number Diff line
@@ -366,6 +366,11 @@ extern int futex_parse_waitv(struct futex_vector *futexv, 
			     unsigned int nr_futexes, futex_wake_fn *wake,

			     void *wake_data);



extern int futex_wait_multiple_setup(struct futex_vector *vs, int count,

				     int *woken);



extern int futex_unqueue_multiple(struct futex_vector *v, int count);



extern int futex_wait_multiple(struct futex_vector *vs, unsigned int count,

			       struct hrtimer_sleeper *to);

kernel/futex/waitwake.c

+5 −5
Original line number Diff line number Diff line
@@ -372,7 +372,7 @@ void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q, 
}



/**

 * unqueue_multiple - Remove various futexes from their hash bucket

 * futex_unqueue_multiple - Remove various futexes from their hash bucket

 * @v:	   The list of futexes to unqueue

 * @count: Number of futexes in the list

 *
@@ -382,7 +382,7 @@ void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q, 
 *  - >=0 - Index of the last futex that was awoken;

 *  - -1  - No futex was awoken

 */

static int unqueue_multiple(struct futex_vector *v, int count)

int futex_unqueue_multiple(struct futex_vector *v, int count)

{

	int ret = -1, i;
@@ -410,7 +410,7 @@ static int unqueue_multiple(struct futex_vector *v, int count) 
 *  -  0 - Success

 *  - <0 - -EFAULT, -EWOULDBLOCK or -EINVAL

 */

static int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *woken)

int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *woken)

{

	struct futex_hash_bucket *hb;

	bool retry = false;
@@ -472,7 +472,7 @@ static int futex_wait_multiple_setup(struct futex_vector *vs, int count, int *wo 
		 * was woken, we don't return error and return this index to

		 * userspace

		 */

		*woken = unqueue_multiple(vs, i);

		*woken = futex_unqueue_multiple(vs, i);

		if (*woken >= 0)

			return 1;
@@ -557,7 +557,7 @@ int futex_wait_multiple(struct futex_vector *vs, unsigned int count, 


		__set_current_state(TASK_RUNNING);



		ret = unqueue_multiple(vs, count);

		ret = futex_unqueue_multiple(vs, count);

		if (ret >= 0)

			return ret;