Displaying 20 results from an estimated 27 matches for "_qlock_locked_slowpath".
2014 Jun 12
2
[PATCH v11 14/16] pvqspinlock: Add qspinlock para-virtualization support
...ck *lock);
> +
> +static inline void queue_spin_unlock(struct qspinlock *lock)
> +{
> + barrier();
> + if (static_key_false(¶virt_spinlocks_enabled)) {
> + /*
> + * Need to atomically clear the lock byte to avoid racing with
> + * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
> + */
> + if (likely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0)
> + == _Q_LOCKED_VAL))
> + return;
> + else
> + queue_spin_unlock_slowpath(lock);
> +
> + } else {
> + __queue_spin_unlock(lock);
> + }
> + barrier();
> +}
> +#endif /* CONFIG_PARAVIRT_SP...
2014 Jun 12
2
[PATCH v11 14/16] pvqspinlock: Add qspinlock para-virtualization support
...ck *lock);
> +
> +static inline void queue_spin_unlock(struct qspinlock *lock)
> +{
> + barrier();
> + if (static_key_false(¶virt_spinlocks_enabled)) {
> + /*
> + * Need to atomically clear the lock byte to avoid racing with
> + * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
> + */
> + if (likely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0)
> + == _Q_LOCKED_VAL))
> + return;
> + else
> + queue_spin_unlock_slowpath(lock);
> +
> + } else {
> + __queue_spin_unlock(lock);
> + }
> + barrier();
> +}
> +#endif /* CONFIG_PARAVIRT_SP...
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
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 Jun 12
0
[PATCH v11 14/16] pvqspinlock: Add qspinlock para-virtualization support
...static inline void queue_spin_unlock(struct qspinlock *lock)
>> +{
>> + barrier();
>> + if (static_key_false(¶virt_spinlocks_enabled)) {
>> + /*
>> + * Need to atomically clear the lock byte to avoid racing with
>> + * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
>> + */
>> + if (likely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0)
>> + == _Q_LOCKED_VAL))
>> + return;
>> + else
>> + queue_spin_unlock_slowpath(lock);
>> +
>> + } else {
>> + __queue_spin_unlock(lock);
>> + }
>> + barrier()...
2014 Nov 03
0
[PATCH v13 09/11] pvqspinlock, x86: Add para-virtualization support
...uct qspinlock *lock)
> {
> barrier();
> + if (!static_key_false(¶virt_spinlocks_enabled)) {
> + native_spin_unlock(lock);
> + return;
> + }
>
> + /*
> + * Need to atomically clear the lock byte to avoid racing with
> + * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
> + */
> + if (unlikely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0) != _Q_LOCKED_VAL))
> + queue_spin_unlock_slowpath(lock);
> +}
Idem, that static key stuff is wrong, use PV ops to switch between
unlock paths.
> @@ -354,7 +394,7 @@ queue:
> * if there was a previous node; link...
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 Oct 29
1
[PATCH v13 09/11] pvqspinlock, x86: Add para-virtualization support
...{
barrier();
- ACCESS_ONCE(*(u8 *)lock) = 0;
-}
+ if (!static_key_false(¶virt_spinlocks_enabled)) {
+ native_spin_unlock(lock);
+ return;
+ }
-#endif /* !CONFIG_X86_PPRO_FENCE */
+ /*
+ * Need to atomically clear the lock byte to avoid racing with
+ * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
+ */
+ if (unlikely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0) != _Q_LOCKED_VAL))
+ queue_spin_unlock_slowpath(lock);
+}
+#else
+static inline void queue_spin_unlock(struct qspinlock *lock)
+{
+ native_spin_unlock(lock);
+}
+#endif /* CONFIG_PARAVIRT_SPINLOCKS */
#define virt_queue_spin_lock virt_...
2014 Oct 29
1
[PATCH v13 09/11] pvqspinlock, x86: Add para-virtualization support
...{
barrier();
- ACCESS_ONCE(*(u8 *)lock) = 0;
-}
+ if (!static_key_false(¶virt_spinlocks_enabled)) {
+ native_spin_unlock(lock);
+ return;
+ }
-#endif /* !CONFIG_X86_PPRO_FENCE */
+ /*
+ * Need to atomically clear the lock byte to avoid racing with
+ * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
+ */
+ if (unlikely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0) != _Q_LOCKED_VAL))
+ queue_spin_unlock_slowpath(lock);
+}
+#else
+static inline void queue_spin_unlock(struct qspinlock *lock)
+{
+ native_spin_unlock(lock);
+}
+#endif /* CONFIG_PARAVIRT_SPINLOCKS */
#define virt_queue_spin_lock virt_...
2014 May 30
0
[PATCH v11 14/16] pvqspinlock: Add qspinlock para-virtualization support
...ueue_spin_unlock_slowpath(struct qspinlock *lock);
+
+static inline void queue_spin_unlock(struct qspinlock *lock)
+{
+ barrier();
+ if (static_key_false(¶virt_spinlocks_enabled)) {
+ /*
+ * Need to atomically clear the lock byte to avoid racing with
+ * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
+ */
+ if (likely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0)
+ == _Q_LOCKED_VAL))
+ return;
+ else
+ queue_spin_unlock_slowpath(lock);
+
+ } else {
+ __queue_spin_unlock(lock);
+ }
+ barrier();
+}
+#endif /* CONFIG_PARAVIRT_SPINLOCKS */
#endif /* !CONFIG_X86_OOSTORE && !CONFIG_X86_...
2014 Oct 16
2
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
...{
barrier();
- ACCESS_ONCE(*(u8 *)lock) = 0;
-}
+ if (!static_key_false(¶virt_spinlocks_enabled)) {
+ native_spin_unlock(lock);
+ return;
+ }
-#endif /* !CONFIG_X86_PPRO_FENCE */
+ /*
+ * Need to atomically clear the lock byte to avoid racing with
+ * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
+ */
+ if (unlikely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0) != _Q_LOCKED_VAL))
+ queue_spin_unlock_slowpath(lock);
+}
+#else
+static inline void queue_spin_unlock(struct qspinlock *lock)
+{
+ native_spin_unlock(lock);
+}
+#endif /* CONFIG_PARAVIRT_SPINLOCKS */
#define virt_queue_spin_lock virt_...
2014 Oct 16
2
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
...{
barrier();
- ACCESS_ONCE(*(u8 *)lock) = 0;
-}
+ if (!static_key_false(¶virt_spinlocks_enabled)) {
+ native_spin_unlock(lock);
+ return;
+ }
-#endif /* !CONFIG_X86_PPRO_FENCE */
+ /*
+ * Need to atomically clear the lock byte to avoid racing with
+ * queue head waiter trying to set _QLOCK_LOCKED_SLOWPATH.
+ */
+ if (unlikely(cmpxchg((u8 *)lock, _Q_LOCKED_VAL, 0) != _Q_LOCKED_VAL))
+ queue_spin_unlock_slowpath(lock);
+}
+#else
+static inline void queue_spin_unlock(struct qspinlock *lock)
+{
+ native_spin_unlock(lock);
+}
+#endif /* CONFIG_PARAVIRT_SPINLOCKS */
#define virt_queue_spin_lock virt_...
2014 Oct 29
15
[PATCH v13 00/11] qspinlock: a 4-byte queue spinlock with PV support
v12->v13:
- Change patch 9 to generate separate versions of the
queue_spin_lock_slowpath functions for bare metal and PV guest. This
reduces the performance impact of the PV code on bare metal systems.
v11->v12:
- Based on PeterZ's version of the qspinlock patch
(https://lkml.org/lkml/2014/6/15/63).
- Incorporated many of the review comments from Konrad Wilk and
Paolo
2014 Oct 29
15
[PATCH v13 00/11] qspinlock: a 4-byte queue spinlock with PV support
v12->v13:
- Change patch 9 to generate separate versions of the
queue_spin_lock_slowpath functions for bare metal and PV guest. This
reduces the performance impact of the PV code on bare metal systems.
v11->v12:
- Based on PeterZ's version of the qspinlock patch
(https://lkml.org/lkml/2014/6/15/63).
- Incorporated many of the review comments from Konrad Wilk and
Paolo
2014 May 30
19
[PATCH v11 00/16] qspinlock: a 4-byte queue spinlock with PV support
v10->v11:
- Use a simple test-and-set unfair lock to simplify the code,
but performance may suffer a bit for large guest with many CPUs.
- Take out Raghavendra KT's test results as the unfair lock changes
may render some of his results invalid.
- Add PV support without increasing the size of the core queue node
structure.
- Other minor changes to address some of the
2014 May 30
19
[PATCH v11 00/16] qspinlock: a 4-byte queue spinlock with PV support
v10->v11:
- Use a simple test-and-set unfair lock to simplify the code,
but performance may suffer a bit for large guest with many CPUs.
- Take out Raghavendra KT's test results as the unfair lock changes
may render some of his results invalid.
- Add PV support without increasing the size of the core queue node
structure.
- Other minor changes to address some of the
2014 Oct 16
15
[PATCH v12 00/11] qspinlock: a 4-byte queue spinlock with PV support
v11->v12:
- Based on PeterZ's version of the qspinlock patch
(https://lkml.org/lkml/2014/6/15/63).
- Incorporated many of the review comments from Konrad Wilk and
Paolo Bonzini.
- The pvqspinlock code is largely from my previous version with
PeterZ's way of going from queue tail to head and his idea of
using callee saved calls to KVM and XEN codes.
v10->v11:
- Use a