From: Jens Axboe <[email protected]>
To: [email protected], [email protected]
Cc: [email protected], [email protected], Jens Axboe <[email protected]>
Subject: [PATCH 05/10] futex: abstract out a __futex_wake_mark() helper
Date: Thu, 20 Jul 2023 16:18:53 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
Move the unqueue and lock_ptr clear into a helper that futex_wake_mark()
calls. Add it to the public functions as well, in preparation for using
it outside the core futex code.
Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
---
kernel/futex/futex.h | 1 +
kernel/futex/waitwake.c | 33 ++++++++++++++++++++++-----------
2 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h
index 2b18eb889cce..98d43e9efe65 100644
--- a/kernel/futex/futex.h
+++ b/kernel/futex/futex.h
@@ -190,6 +190,7 @@ extern int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
struct futex_q *q, struct futex_hash_bucket **hb);
extern void futex_wait_queue(struct futex_hash_bucket *hb, struct futex_q *q,
struct hrtimer_sleeper *timeout);
+extern bool __futex_wake_mark(struct futex_q *q);
extern void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q);
extern int fault_in_user_writeable(u32 __user *uaddr);
diff --git a/kernel/futex/waitwake.c b/kernel/futex/waitwake.c
index 0272b8c3b132..86f67f652b95 100644
--- a/kernel/futex/waitwake.c
+++ b/kernel/futex/waitwake.c
@@ -106,20 +106,11 @@
* double_lock_hb() and double_unlock_hb(), respectively.
*/
-/*
- * The hash bucket lock must be held when this is called.
- * Afterwards, the futex_q must not be accessed. Callers
- * must ensure to later call wake_up_q() for the actual
- * wakeups to occur.
- */
-void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q)
+bool __futex_wake_mark(struct futex_q *q)
{
- struct task_struct *p = q->task;
-
if (WARN(q->pi_state || q->rt_waiter, "refusing to wake PI futex\n"))
- return;
+ return false;
- get_task_struct(p);
__futex_unqueue(q);
/*
* The waiting task can free the futex_q as soon as q->lock_ptr = NULL
@@ -130,6 +121,26 @@ void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q)
*/
smp_store_release(&q->lock_ptr, NULL);
+ return true;
+}
+
+/*
+ * The hash bucket lock must be held when this is called.
+ * Afterwards, the futex_q must not be accessed. Callers
+ * must ensure to later call wake_up_q() for the actual
+ * wakeups to occur.
+ */
+void futex_wake_mark(struct wake_q_head *wake_q, struct futex_q *q)
+{
+ struct task_struct *p = q->task;
+
+ get_task_struct(p);
+
+ if (!__futex_wake_mark(q)) {
+ put_task_struct(p);
+ return;
+ }
+
/*
* Queue the task for later wakeup for after we've released
* the hb->lock.
--
2.40.1
next prev parent reply other threads:[~2023-07-20 22:19 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 22:18 [PATCHSET v3 0/10] Add io_uring futex/futexv support Jens Axboe
2023-07-20 22:18 ` [PATCH 01/10] futex: Clarify FUTEX2 flags Jens Axboe
2023-07-20 22:18 ` [PATCH 02/10] futex: Extend the " Jens Axboe
2023-07-20 22:18 ` [PATCH 03/10] futex: Flag conversion Jens Axboe
2023-07-20 22:18 ` [PATCH 04/10] futex: factor out the futex wake handling Jens Axboe
2023-07-20 22:18 ` Jens Axboe [this message]
2023-07-20 22:18 ` [PATCH 06/10] io_uring: add support for futex wake and wait Jens Axboe
2023-07-21 11:30 ` Peter Zijlstra
2023-07-21 11:37 ` Peter Zijlstra
2023-07-21 14:43 ` Jens Axboe
2023-07-21 15:29 ` Jens Axboe
2023-07-25 13:00 ` Peter Zijlstra
2023-07-25 13:48 ` Jens Axboe
2023-07-25 13:57 ` Jens Axboe
2023-07-25 15:19 ` Peter Zijlstra
2023-07-25 20:42 ` Jens Axboe
2023-07-25 21:24 ` Jens Axboe
2023-07-25 14:06 ` Peter Zijlstra
2023-07-20 22:18 ` [PATCH 07/10] futex: add wake_data to struct futex_q Jens Axboe
2023-07-20 22:18 ` [PATCH 08/10] futex: make futex_parse_waitv() available as a helper Jens Axboe
2023-07-20 22:18 ` [PATCH 09/10] futex: make the vectored futex operations available Jens Axboe
2023-07-20 22:18 ` [PATCH 10/10] io_uring: add support for vectored futex waits Jens Axboe
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