Displaying 20 results from an estimated 54 matches for "pv_wait_head".
2015 Apr 02
3
[PATCH 8/9] qspinlock: Generic paravirt support
...a full barrier, so that guarantees that if we observe
_Q_SLOW_VAL we must also observe the hash bucket with the lock value.
> So we need to have
> some kind of synchronization mechanism to let the lookup CPU know when is a
> good time to look up.
No, its all already ordered and working.
pv_wait_head():
pv_hash()
/* MB as per cmpxchg */
cmpxchg(&l->locked, _Q_LOCKED_VAL, _Q_SLOW_VAL);
VS
__pv_queue_spin_unlock():
if (xchg(&l->locked, 0) != _Q_SLOW_VAL)
return;
/* MB as per xchg */
pv_hash_find(lock);
2015 Apr 02
3
[PATCH 8/9] qspinlock: Generic paravirt support
...a full barrier, so that guarantees that if we observe
_Q_SLOW_VAL we must also observe the hash bucket with the lock value.
> So we need to have
> some kind of synchronization mechanism to let the lookup CPU know when is a
> good time to look up.
No, its all already ordered and working.
pv_wait_head():
pv_hash()
/* MB as per cmpxchg */
cmpxchg(&l->locked, _Q_LOCKED_VAL, _Q_SLOW_VAL);
VS
__pv_queue_spin_unlock():
if (xchg(&l->locked, 0) != _Q_SLOW_VAL)
return;
/* MB as per xchg */
pv_hash_find(lock);
2015 Mar 18
2
[PATCH 8/9] qspinlock: Generic paravirt support
...> + */
> +
> +static __always_inline void __pv_init_node(struct mcs_spinlock *node) { }
> +static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
> +static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
> +
> +static __always_inline void __pv_wait_head(struct qspinlock *lock) { }
> +
> +#define pv_enabled() false
> +
> +#define pv_init_node __pv_init_node
> +#define pv_wait_node __pv_wait_node
> +#define pv_kick_node __pv_kick_node
> +
> +#define pv_wait_head __pv_wait_head
> +
> +#ifdef CONFIG_PARAVIRT_SPINLOCK...
2015 Mar 18
2
[PATCH 8/9] qspinlock: Generic paravirt support
...> + */
> +
> +static __always_inline void __pv_init_node(struct mcs_spinlock *node) { }
> +static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
> +static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
> +
> +static __always_inline void __pv_wait_head(struct qspinlock *lock) { }
> +
> +#define pv_enabled() false
> +
> +#define pv_init_node __pv_init_node
> +#define pv_wait_node __pv_wait_node
> +#define pv_kick_node __pv_kick_node
> +
> +#define pv_wait_head __pv_wait_head
> +
> +#ifdef CONFIG_PARAVIRT_SPINLOCK...
2015 Mar 19
0
[PATCH 8/9] qspinlock: Generic paravirt support
...e(struct mcs_spinlock *node) { }
-static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_wait_node(u32 old, struct mcs_spinlock *node) { }
static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
-static __always_inline void __pv_wait_head(struct qspinlock *lock) { }
+static __always_inline void __pv_wait_head(struct qspinlock *lock, struct mcs_spinlock *node) { }
#define pv_enabled() false
@@ -399,7 +399,7 @@ void queue_spin_lock_slowpath(struct qsp
prev = decode_tail(old);
WRITE_ONCE(p...
2015 Mar 19
0
[PATCH 8/9] qspinlock: Generic paravirt support
...e(struct mcs_spinlock *node) { }
-static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_wait_node(u32 old, struct mcs_spinlock *node) { }
static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
-static __always_inline void __pv_wait_head(struct qspinlock *lock) { }
+static __always_inline void __pv_wait_head(struct qspinlock *lock, struct mcs_spinlock *node) { }
#define pv_enabled() false
@@ -399,7 +399,7 @@ void queue_spin_lock_slowpath(struct qsp
prev = decode_tail(old);
WRITE_ONCE(p...
2015 Apr 02
0
[PATCH 8/9] qspinlock: Generic paravirt support
On Thu, Apr 02, 2015 at 07:20:57PM +0200, Peter Zijlstra wrote:
> pv_wait_head():
>
> pv_hash()
> /* MB as per cmpxchg */
> cmpxchg(&l->locked, _Q_LOCKED_VAL, _Q_SLOW_VAL);
>
> VS
>
> __pv_queue_spin_unlock():
>
> if (xchg(&l->locked, 0) != _Q_SLOW_VAL)
> return;
>
> /* MB as per xchg */
> pv_hash_find(lock)...
2014 Oct 27
2
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
...struct pv_qnode *ppn, *pn = (struct pv_qnode *)node;
unsigned int count;
- if (!pv_enabled())
- return false;
-
if (!(old & _Q_TAIL_MASK)) {
node->locked = true; /* At queue head now */
goto ret;
@@ -236,9 +230,6 @@ pv_wait_head(struct qspinlock *lock, struct
mcs_spinlock *no
{
struct pv_qnode *pn = (struct pv_qnode *)node;
- if (!pv_enabled())
- return smp_load_acquire(&lock->val.counter);
-
for (;;) {
unsigned int count;
s8 oldstate;
@@ -3...
2014 Oct 27
2
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
...struct pv_qnode *ppn, *pn = (struct pv_qnode *)node;
unsigned int count;
- if (!pv_enabled())
- return false;
-
if (!(old & _Q_TAIL_MASK)) {
node->locked = true; /* At queue head now */
goto ret;
@@ -236,9 +230,6 @@ pv_wait_head(struct qspinlock *lock, struct
mcs_spinlock *no
{
struct pv_qnode *pn = (struct pv_qnode *)node;
- if (!pv_enabled())
- return smp_load_acquire(&lock->val.counter);
-
for (;;) {
unsigned int count;
s8 oldstate;
@@ -3...
2015 Apr 07
0
[PATCH v15 13/15] pvqspinlock: Only kick CPU at unlock time
...ode) { }
static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
-static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
-
+static __always_inline void __pv_scan_next(struct qspinlock *lock,
+ struct mcs_spinlock *node) { }
static __always_inline void __pv_wait_head(struct qspinlock *lock,
struct mcs_spinlock *node) { }
@@ -248,7 +248,7 @@ static __always_inline void __pv_wait_head(struct qspinlock *lock,
#define pv_init_node __pv_init_node
#define pv_wait_node __pv_wait_node
-#define pv_kick_node __pv_kick_node
+#define pv_scan_next __pv_sc...
2015 Mar 16
0
[PATCH 8/9] qspinlock: Generic paravirt support
...NOPs for
+ * all the PV callbacks.
+ */
+
+static __always_inline void __pv_init_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
+
+static __always_inline void __pv_wait_head(struct qspinlock *lock) { }
+
+#define pv_enabled() false
+
+#define pv_init_node __pv_init_node
+#define pv_wait_node __pv_wait_node
+#define pv_kick_node __pv_kick_node
+
+#define pv_wait_head __pv_wait_head
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+#define queue_spin_lock_slowpath native_queue_s...
2015 Mar 16
0
[PATCH 8/9] qspinlock: Generic paravirt support
...NOPs for
+ * all the PV callbacks.
+ */
+
+static __always_inline void __pv_init_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
+
+static __always_inline void __pv_wait_head(struct qspinlock *lock) { }
+
+#define pv_enabled() false
+
+#define pv_init_node __pv_init_node
+#define pv_wait_node __pv_wait_node
+#define pv_kick_node __pv_kick_node
+
+#define pv_wait_head __pv_wait_head
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+#define queue_spin_lock_slowpath native_queue_s...
2014 Oct 24
3
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
On 10/24/2014 04:47 AM, Peter Zijlstra wrote:
> On Thu, Oct 16, 2014 at 02:10:38PM -0400, Waiman Long wrote:
>> +static inline void pv_init_node(struct mcs_spinlock *node)
>> +{
>> + struct pv_qnode *pn = (struct pv_qnode *)node;
>> +
>> + BUILD_BUG_ON(sizeof(struct pv_qnode)> 5*sizeof(struct mcs_spinlock));
>> +
>> + if (!pv_enabled())
>> +
2014 Oct 24
3
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
On 10/24/2014 04:47 AM, Peter Zijlstra wrote:
> On Thu, Oct 16, 2014 at 02:10:38PM -0400, Waiman Long wrote:
>> +static inline void pv_init_node(struct mcs_spinlock *node)
>> +{
>> + struct pv_qnode *pn = (struct pv_qnode *)node;
>> +
>> + BUILD_BUG_ON(sizeof(struct pv_qnode)> 5*sizeof(struct mcs_spinlock));
>> +
>> + if (!pv_enabled())
>> +
2015 Apr 07
0
[PATCH v15 09/15] pvqspinlock: Implement simple paravirt support for the qspinlock
...NOPs for
+ * all the PV callbacks.
+ */
+
+static __always_inline void __pv_init_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
+
+static __always_inline void __pv_wait_head(struct qspinlock *lock,
+ struct mcs_spinlock *node) { }
+
+#define pv_enabled() false
+
+#define pv_init_node __pv_init_node
+#define pv_wait_node __pv_wait_node
+#define pv_kick_node __pv_kick_node
+
+#define pv_wait_head __pv_wait_head
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+#define que...
2014 Oct 29
1
[PATCH v13 09/11] pvqspinlock, x86: Add para-virtualization support
...head will have to be kicked on unlock.
- queue_unlock; this routine has a jump label to check if paravirt
is enabled. If yes, it has to do an atomic cmpxchg to clear the lock
bit or call the slowpath function to kick the queue head cpu.
Tracking the head is done in two parts, firstly the pv_wait_head will
store its cpu number in whichever node is pointed to by the tail part
of the lock word. Secondly, pv_link_and_wait_node() will propagate the
existing head from the old to the new tail node.
Signed-off-by: Waiman Long <Waiman.Long at hp.com>
---
arch/x86/include/asm/paravirt.h |...
2014 Oct 29
1
[PATCH v13 09/11] pvqspinlock, x86: Add para-virtualization support
...head will have to be kicked on unlock.
- queue_unlock; this routine has a jump label to check if paravirt
is enabled. If yes, it has to do an atomic cmpxchg to clear the lock
bit or call the slowpath function to kick the queue head cpu.
Tracking the head is done in two parts, firstly the pv_wait_head will
store its cpu number in whichever node is pointed to by the tail part
of the lock word. Secondly, pv_link_and_wait_node() will propagate the
existing head from the old to the new tail node.
Signed-off-by: Waiman Long <Waiman.Long at hp.com>
---
arch/x86/include/asm/paravirt.h |...
2014 Jun 15
0
[PATCH 10/11] qspinlock: Paravirt support
...the regular data.
- link_and_wait_node/kick_node; these are paired with the regular MCS
queueing and are placed resp. before/after the paired MCS ops.
- wait_head/queue_unlock; the interesting part here is finding the
head node to kick.
Tracking the head is done in two parts, firstly the pv_wait_head will
store its cpu number in whichever node is pointed to by the tail part
of the lock word. Secondly, pv_link_and_wait_node() will propagate the
existing head from the old to the new tail node.
Signed-off-by: Peter Zijlstra <peterz at infradead.org>
---
arch/x86/include/asm/paravirt.h...
2015 Apr 24
0
[PATCH v16 08/14] pvqspinlock: Implement simple paravirt support for the qspinlock
...NOPs for
+ * all the PV callbacks.
+ */
+
+static __always_inline void __pv_init_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_wait_node(struct mcs_spinlock *node) { }
+static __always_inline void __pv_kick_node(struct mcs_spinlock *node) { }
+
+static __always_inline void __pv_wait_head(struct qspinlock *lock,
+ struct mcs_spinlock *node) { }
+
+#define pv_enabled() false
+
+#define pv_init_node __pv_init_node
+#define pv_wait_node __pv_wait_node
+#define pv_kick_node __pv_kick_node
+#define pv_wait_head __pv_wait_head
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+#define queue...
2014 Oct 16
2
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
...head will have to be kicked on unlock.
- queue_unlock; this routine has a jump label to check if paravirt
is enabled. If yes, it has to do an atomic cmpxchg to clear the lock
bit or call the slowpath function to kick the queue head cpu.
Tracking the head is done in two parts, firstly the pv_wait_head will
store its cpu number in whichever node is pointed to by the tail part
of the lock word. Secondly, pv_link_and_wait_node() will propagate the
existing head from the old to the new tail node.
Signed-off-by: Waiman Long <Waiman.Long at hp.com>
---
arch/x86/include/asm/paravirt.h |...