From: Waiman Long <longman@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Jonathan Corbet <corbet@lwn.net>
Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Mike Galbraith <umgwanakikbuti@gmail.com>,
Scott J Norton <scott.norton@hpe.com>,
Waiman Long <longman@redhat.com>
Subject: [PATCH v4 04/20] futex: Consolidate pure pi_state_list add & delete codes to helpers
Date: Thu, 29 Dec 2016 11:13:30 -0500 [thread overview]
Message-ID: <1483028026-10305-5-git-send-email-longman@redhat.com> (raw)
In-Reply-To: <1483028026-10305-1-git-send-email-longman@redhat.com>
Two new helper functions (task_pi_list_add & task_pi_list_del)
are created to consolidate all the pure pi_state_list addition and
insertion codes. The set_owner argument in task_pi_list_add() will
be needed in a later patch.
Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/futex.c | 64 +++++++++++++++++++++++++++++++++++-----------------------
1 file changed, 39 insertions(+), 25 deletions(-)
diff --git a/kernel/futex.c b/kernel/futex.c
index 7590c7d..ccec962 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -822,6 +822,39 @@ static inline int get_futex_value(u32 *dest, u32 __user *from)
/*
* PI code:
*/
+
+/**
+ * task_pi_list_add - add futex state object to a task's pi_state_list
+ * @task : task structure
+ * @state: futex state object
+ */
+static inline void task_pi_list_add(struct task_struct *task,
+ struct futex_state *state)
+{
+ raw_spin_lock_irq(&task->pi_lock);
+ WARN_ON(!list_empty(&state->list));
+ list_add(&state->list, &task->pi_state_list);
+ state->owner = task;
+ raw_spin_unlock_irq(&task->pi_lock);
+}
+
+/**
+ * task_pi_list_del - delete futex state object from a task's pi_state_list
+ * @state: futex state object
+ * @warn : warn if list is empty when set
+ */
+static inline void task_pi_list_del(struct futex_state *state, const bool warn)
+{
+ struct task_struct *task = state->owner;
+
+ raw_spin_lock_irq(&task->pi_lock);
+ if (warn)
+ WARN_ON(list_empty(&state->list));
+ list_del_init(&state->list);
+ state->owner = NULL;
+ raw_spin_unlock_irq(&task->pi_lock);
+}
+
static int refill_futex_state_cache(void)
{
struct futex_state *state;
@@ -874,9 +907,7 @@ static void put_futex_state(struct futex_state *state)
* and has cleaned up the futex state already
*/
if (state->owner) {
- raw_spin_lock_irq(&state->owner->pi_lock);
- list_del_init(&state->list);
- raw_spin_unlock_irq(&state->owner->pi_lock);
+ task_pi_list_del(state, false);
rt_mutex_proxy_unlock(&state->pi_mutex, state->owner);
}
@@ -1397,16 +1428,8 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this,
return ret;
}
- raw_spin_lock(&pi_state->owner->pi_lock);
- WARN_ON(list_empty(&pi_state->list));
- list_del_init(&pi_state->list);
- raw_spin_unlock(&pi_state->owner->pi_lock);
-
- raw_spin_lock(&new_owner->pi_lock);
- WARN_ON(!list_empty(&pi_state->list));
- list_add(&pi_state->list, &new_owner->pi_state_list);
- pi_state->owner = new_owner;
- raw_spin_unlock(&new_owner->pi_lock);
+ task_pi_list_del(pi_state, true);
+ task_pi_list_add(new_owner, pi_state);
raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);
@@ -2211,19 +2234,10 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct futex_q *q,
* We fixed up user space. Now we need to fix the pi_state
* itself.
*/
- if (pi_state->owner != NULL) {
- raw_spin_lock_irq(&pi_state->owner->pi_lock);
- WARN_ON(list_empty(&pi_state->list));
- list_del_init(&pi_state->list);
- raw_spin_unlock_irq(&pi_state->owner->pi_lock);
- }
+ if (pi_state->owner != NULL)
+ task_pi_list_del(pi_state, true);
- pi_state->owner = newowner;
-
- raw_spin_lock_irq(&newowner->pi_lock);
- WARN_ON(!list_empty(&pi_state->list));
- list_add(&pi_state->list, &newowner->pi_state_list);
- raw_spin_unlock_irq(&newowner->pi_lock);
+ task_pi_list_add(newowner, pi_state);
return 0;
/*
--
1.8.3.1
next prev parent reply other threads:[~2016-12-29 16:18 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-29 16:13 [PATCH v4 00/20] futex: Introducing throughput-optimized (TP) futexes Waiman Long
2016-12-29 16:13 ` [PATCH v4 01/20] futex: Consolidate duplicated timer setup code Waiman Long
2016-12-29 16:13 ` [PATCH v4 02/20] futex: Rename futex_pi_state to futex_state Waiman Long
2016-12-29 16:13 ` [PATCH v4 03/20] futex: Add helpers to get & cmpxchg futex value without lock Waiman Long
2016-12-29 16:13 ` Waiman Long [this message]
2016-12-29 16:13 ` [PATCH v4 05/20] futex: Add a new futex type field into futex_state Waiman Long
2016-12-29 16:13 ` [PATCH v4 06/20] futex: Allow direct attachment of futex_state objects to hash bucket Waiman Long
2016-12-29 16:13 ` [PATCH v4 07/20] futex: Introduce throughput-optimized (TP) futexes Waiman Long
2016-12-29 21:17 ` kbuild test robot
2016-12-29 16:13 ` [PATCH v4 08/20] TP-futex: Enable robust handling Waiman Long
2016-12-29 16:13 ` [PATCH v4 09/20] TP-futex: Implement lock handoff to prevent lock starvation Waiman Long
2016-12-29 16:13 ` [PATCH v4 10/20] TP-futex: Return status code on FUTEX_LOCK calls Waiman Long
2016-12-29 16:13 ` [PATCH v4 11/20] TP-futex: Add timeout support Waiman Long
2016-12-29 16:13 ` [PATCH v4 12/20] TP-futex, doc: Add TP futexes documentation Waiman Long
2016-12-29 16:13 ` [PATCH v4 13/20] perf bench: New microbenchmark for userspace mutex performance Waiman Long
2017-01-02 17:16 ` Arnaldo Carvalho de Melo
2017-01-02 18:17 ` Waiman Long
2016-12-29 16:13 ` [PATCH v4 14/20] TP-futex: Support userspace reader/writer locks Waiman Long
2016-12-29 18:34 ` kbuild test robot
2016-12-29 16:13 ` [PATCH v4 15/20] TP-futex: Enable kernel reader lock stealing Waiman Long
2016-12-29 16:13 ` [PATCH v4 16/20] TP-futex: Group readers together in wait queue Waiman Long
2016-12-29 19:53 ` kbuild test robot
2016-12-29 20:16 ` kbuild test robot
2016-12-29 16:13 ` [PATCH v4 17/20] TP-futex, doc: Update TP futexes document on shared locking Waiman Long
2016-12-29 16:13 ` [PATCH v4 18/20] perf bench: New microbenchmark for userspace rwlock performance Waiman Long
2016-12-29 16:13 ` [PATCH v4 19/20] sched, TP-futex: Make wake_up_q() return wakeup count Waiman Long
2016-12-29 16:13 ` [PATCH v4 20/20] futex: Dump internal futex state via debugfs Waiman Long
2016-12-29 18:55 ` kbuild test robot
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