Displaying 20 results from an estimated 20 matches for "put_qnode".
2014 Feb 26
1
[PATCH v5 1/8] qspinlock: Introducing a 4-byte queue spinlock implementation
On Wed, Feb 26, 2014 at 10:14:21AM -0500, Waiman Long wrote:
> +static void put_qnode(void)
> +{
> + struct qnode_set *qset = this_cpu_ptr(&qnset);
> +
> + qset->node_idx--;
> +}
That very much wants to be: this_cpu_dec().
2014 Feb 26
1
[PATCH v5 1/8] qspinlock: Introducing a 4-byte queue spinlock implementation
On Wed, Feb 26, 2014 at 10:14:21AM -0500, Waiman Long wrote:
> +static void put_qnode(void)
> +{
> + struct qnode_set *qset = this_cpu_ptr(&qnset);
> +
> + qset->node_idx--;
> +}
That very much wants to be: this_cpu_dec().
2014 Mar 02
1
[PATCH v5 1/8] qspinlock: Introducing a 4-byte queue spinlock implementation
...node
> + */
> + node->wait = true;
> + node->next = NULL;
> +
> + /*
> + * The lock may be available at this point, try again if no task was
> + * waiting in the queue.
> + */
> + if (!(qsval >> _QCODE_OFFSET) && queue_spin_trylock(lock)) {
> + put_qnode();
> + return;
> + }
Cosmetic, but probably "goto release_node" would be more consistent.
And I am wondering how much this "qsval >> _QCODE_OFFSET" check can help.
Note that this is the only usage of this arg, perhaps it would be better
to simply remove it and shr...
2014 Mar 02
1
[PATCH v5 1/8] qspinlock: Introducing a 4-byte queue spinlock implementation
...node
> + */
> + node->wait = true;
> + node->next = NULL;
> +
> + /*
> + * The lock may be available at this point, try again if no task was
> + * waiting in the queue.
> + */
> + if (!(qsval >> _QCODE_OFFSET) && queue_spin_trylock(lock)) {
> + put_qnode();
> + return;
> + }
Cosmetic, but probably "goto release_node" would be more consistent.
And I am wondering how much this "qsval >> _QCODE_OFFSET" check can help.
Note that this is the only usage of this arg, perhaps it would be better
to simply remove it and shr...
2014 Feb 26
0
[PATCH v5 1/8] qspinlock: Introducing a 4-byte queue spinlock implementation
...node available.
+ */
+static struct qnode *get_qnode(unsigned int *qn_idx)
+{
+ struct qnode_set *qset = this_cpu_ptr(&qnset);
+ int i;
+
+ if (unlikely(qset->node_idx >= MAX_QNODES))
+ return NULL;
+ i = qset->node_idx++;
+ *qn_idx = i;
+ return &qset->nodes[i];
+}
+
+/**
+ * put_qnode - Return a queue node to the pool
+ */
+static void put_qnode(void)
+{
+ struct qnode_set *qset = this_cpu_ptr(&qnset);
+
+ qset->node_idx--;
+}
+
+/**
+ * queue_spin_lock_slowpath - acquire the queue spinlock
+ * @lock : Pointer to queue spinlock structure
+ * @qsval: Current value of the q...
2014 Feb 27
0
[PATCH v5 1/8] qspinlock: Introducing a 4-byte queue spinlock implementation
...node available.
+ */
+static struct qnode *get_qnode(unsigned int *qn_idx)
+{
+ struct qnode_set *qset = this_cpu_ptr(&qnset);
+ int i;
+
+ if (unlikely(qset->node_idx >= MAX_QNODES))
+ return NULL;
+ i = qset->node_idx++;
+ *qn_idx = i;
+ return &qset->nodes[i];
+}
+
+/**
+ * put_qnode - Return a queue node to the pool
+ */
+static void put_qnode(void)
+{
+ struct qnode_set *qset = this_cpu_ptr(&qnset);
+
+ qset->node_idx--;
+}
+
+/**
+ * queue_spin_lock_slowpath - acquire the queue spinlock
+ * @lock : Pointer to queue spinlock structure
+ * @qsval: Current value of the q...
2014 Apr 02
0
[PATCH v8 01/10] qspinlock: A generic 4-byte queue spinlock implementation
...truct qnode_set *qset = this_cpu_ptr(&qnset);
+ int qn_idx = qset->node_idx++;
+
+ /*
+ * It should never happen that all the queue nodes are being used.
+ */
+ BUG_ON(qn_idx >= MAX_QNODES);
+ *qcode = queue_encode_qcode(cpu, qn_idx);
+ return qset->nodes + qn_idx;
+}
+
+/**
+ * put_qnode - Return a queue node to the pool
+ */
+static inline void put_qnode(void)
+{
+ this_cpu_dec(qnset.node_idx);
+}
+
+/**
+ * queue_spin_lock_slowpath - acquire the queue spinlock
+ * @lock : Pointer to queue spinlock structure
+ * @qsval: Current value of the queue spinlock 32-bit word
+ */
+void qu...
2014 Feb 27
14
[PATCH v5 0/8] qspinlock: a 4-byte queue spinlock with PV support
v4->v5:
- Move the optimized 2-task contending code to the generic file to
enable more architectures to use it without code duplication.
- Address some of the style-related comments by PeterZ.
- Allow the use of unfair queue spinlock in a real para-virtualized
execution environment.
- Add para-virtualization support to the qspinlock code by ensuring
that the lock holder and queue
2014 Feb 27
14
[PATCH v5 0/8] qspinlock: a 4-byte queue spinlock with PV support
v4->v5:
- Move the optimized 2-task contending code to the generic file to
enable more architectures to use it without code duplication.
- Address some of the style-related comments by PeterZ.
- Allow the use of unfair queue spinlock in a real para-virtualized
execution environment.
- Add para-virtualization support to the qspinlock code by ensuring
that the lock holder and queue
2014 Apr 01
10
[PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support
v7->v8:
- Remove one unneeded atomic operation from the slowpath, thus
improving performance.
- Simplify some of the codes and add more comments.
- Test for X86_FEATURE_HYPERVISOR CPU feature bit to enable/disable
unfair lock.
- Reduce unfair lock slowpath lock stealing frequency depending
on its distance from the queue head.
- Add performance data for IvyBridge-EX CPU.
2014 Apr 01
10
[PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support
v7->v8:
- Remove one unneeded atomic operation from the slowpath, thus
improving performance.
- Simplify some of the codes and add more comments.
- Test for X86_FEATURE_HYPERVISOR CPU feature bit to enable/disable
unfair lock.
- Reduce unfair lock slowpath lock stealing frequency depending
on its distance from the queue head.
- Add performance data for IvyBridge-EX CPU.
2014 Feb 26
22
[PATCH v5 0/8] qspinlock: a 4-byte queue spinlock with PV support
v4->v5:
- Move the optimized 2-task contending code to the generic file to
enable more architectures to use it without code duplication.
- Address some of the style-related comments by PeterZ.
- Allow the use of unfair queue spinlock in a real para-virtualized
execution environment.
- Add para-virtualization support to the qspinlock code by ensuring
that the lock holder and queue
2014 Feb 26
22
[PATCH v5 0/8] qspinlock: a 4-byte queue spinlock with PV support
v4->v5:
- Move the optimized 2-task contending code to the generic file to
enable more architectures to use it without code duplication.
- Address some of the style-related comments by PeterZ.
- Allow the use of unfair queue spinlock in a real para-virtualized
execution environment.
- Add para-virtualization support to the qspinlock code by ensuring
that the lock holder and queue
2014 Mar 12
0
[PATCH RFC v6 09/11] pvqspinlock, x86: Add qspinlock para-virtualization support
...pv_head_spin_check(&node->pv, PV_VAR(&hcnt), prev_qcode, lock);
}
notify_next:
@@ -596,9 +646,53 @@ notify_next:
/*
* The next one in queue is now at the head
*/
+ pv_next_node_check(&next->pv, lock);
smp_store_release(&next->wait, false);
release_node:
put_qnode();
}
EXPORT_SYMBOL(queue_spin_lock_slowpath);
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+/**
+ * queue_spin_unlock_slowpath - kick up the CPU of the queue head
+ * @lock : Pointer to queue spinlock structure
+ *
+ * The lock is released after finding the queue head to avoid racing
+ * condition between...
2014 Apr 02
17
[PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support
N.B. Sorry for the duplicate. This patch series were resent as the
original one was rejected by the vger.kernel.org list server
due to long header. There is no change in content.
v7->v8:
- Remove one unneeded atomic operation from the slowpath, thus
improving performance.
- Simplify some of the codes and add more comments.
- Test for X86_FEATURE_HYPERVISOR CPU feature bit
2014 Apr 02
17
[PATCH v8 00/10] qspinlock: a 4-byte queue spinlock with PV support
N.B. Sorry for the duplicate. This patch series were resent as the
original one was rejected by the vger.kernel.org list server
due to long header. There is no change in content.
v7->v8:
- Remove one unneeded atomic operation from the slowpath, thus
improving performance.
- Simplify some of the codes and add more comments.
- Test for X86_FEATURE_HYPERVISOR CPU feature bit
2014 Mar 12
17
[PATCH v6 00/11] qspinlock: a 4-byte queue spinlock with PV support
v5->v6:
- Change the optimized 2-task contending code to make it fairer at the
expense of a bit of performance.
- Add a patch to support unfair queue spinlock for Xen.
- Modify the PV qspinlock code to follow what was done in the PV
ticketlock.
- Add performance data for the unfair lock as well as the PV
support code.
v4->v5:
- Move the optimized 2-task contending code to the
2014 Mar 12
17
[PATCH v6 00/11] qspinlock: a 4-byte queue spinlock with PV support
v5->v6:
- Change the optimized 2-task contending code to make it fairer at the
expense of a bit of performance.
- Add a patch to support unfair queue spinlock for Xen.
- Modify the PV qspinlock code to follow what was done in the PV
ticketlock.
- Add performance data for the unfair lock as well as the PV
support code.
v4->v5:
- Move the optimized 2-task contending code to the
2014 Mar 19
15
[PATCH v7 00/11] qspinlock: a 4-byte queue spinlock with PV support
v6->v7:
- Remove an atomic operation from the 2-task contending code
- Shorten the names of some macros
- Make the queue waiter to attempt to steal lock when unfair lock is
enabled.
- Remove lock holder kick from the PV code and fix a race condition
- Run the unfair lock & PV code on overcommitted KVM guests to collect
performance data.
v5->v6:
- Change the optimized
2014 Mar 19
15
[PATCH v7 00/11] qspinlock: a 4-byte queue spinlock with PV support
v6->v7:
- Remove an atomic operation from the 2-task contending code
- Shorten the names of some macros
- Make the queue waiter to attempt to steal lock when unfair lock is
enabled.
- Remove lock holder kick from the PV code and fix a race condition
- Run the unfair lock & PV code on overcommitted KVM guests to collect
performance data.
v5->v6:
- Change the optimized