Displaying 20 results from an estimated 167 matches for "queue_spin_lock_slowpath".
2015 Mar 16
0
[PATCH 8/9] qspinlock: Generic paravirt support
...kernel/locking/qspinlock_paravirt.h | 177 ++++++++++++++++++++++++++++++++++++
3 files changed, 248 insertions(+), 1 deletion(-)
--- a/include/asm-generic/qspinlock.h
+++ b/include/asm-generic/qspinlock.h
@@ -118,6 +118,9 @@ static __always_inline bool virt_queue_s
}
#endif
+extern void __pv_queue_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_queue_spin_unlock(struct qspinlock *lock);
+
/*
* Initializier
*/
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -18,6 +18,9 @@
* Authors: Waiman Long <waiman.long at hp.com>
* Peter Zijlstra <peter...
2015 Mar 16
0
[PATCH 8/9] qspinlock: Generic paravirt support
...kernel/locking/qspinlock_paravirt.h | 177 ++++++++++++++++++++++++++++++++++++
3 files changed, 248 insertions(+), 1 deletion(-)
--- a/include/asm-generic/qspinlock.h
+++ b/include/asm-generic/qspinlock.h
@@ -118,6 +118,9 @@ static __always_inline bool virt_queue_s
}
#endif
+extern void __pv_queue_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_queue_spin_unlock(struct qspinlock *lock);
+
/*
* Initializier
*/
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -18,6 +18,9 @@
* Authors: Waiman Long <waiman.long at hp.com>
* Peter Zijlstra <peter...
2014 Oct 27
2
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
...f people care about performance they should not be using virt crap :-)
>
> I only really care about bare metal.
Yes, I am aware of that. However, the whole point of doing PV spinlock
is to improve performance in a virtual guest.
Anyway, I had done some measurements. In my test system, the
queue_spin_lock_slowpath() function has a text size of about 400 bytes
without PV, but 1120 bytes with PV. I made some changes to create
separate versions of PV and non-PV slowpath functions as shown by the
diff below. The text size is now about 430 bytes for the non-PV version
and 925 bytes for the PV version. The ove...
2014 Oct 27
2
[PATCH v12 09/11] pvqspinlock, x86: Add para-virtualization support
...f people care about performance they should not be using virt crap :-)
>
> I only really care about bare metal.
Yes, I am aware of that. However, the whole point of doing PV spinlock
is to improve performance in a virtual guest.
Anyway, I had done some measurements. In my test system, the
queue_spin_lock_slowpath() function has a text size of about 400 bytes
without PV, but 1120 bytes with PV. I made some changes to create
separate versions of PV and non-PV slowpath functions as shown by the
diff below. The text size is now about 430 bytes for the non-PV version
and 925 bytes for the PV version. The ove...
2014 May 07
0
[PATCH v10 09/19] qspinlock: Prepare for unfair lock support
If unfair lock is supported, the lock acquisition loop at the end of
the queue_spin_lock_slowpath() function may need to detect the fact
the lock can be stolen. Code are added for the stolen lock detection.
A new qhead macro is also defined as a shorthand for mcs.locked.
Signed-off-by: Waiman Long <Waiman.Long at hp.com>
---
kernel/locking/qspinlock.c | 26 +++++++++++++++++++-------...
2014 May 07
0
[PATCH v10 03/19] qspinlock: Add pending bit
...pu_relax();
+
+ /*
+ * take ownership and clear the pending bit.
+ *
+ * *,1,0 -> *,0,1
+ */
+ for (;;) {
+ new = (val & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL;
+
+ old = atomic_cmpxchg(&lock->val, val, new);
+ if (old == val)
+ break;
+
+ val = old;
+ }
+ return 1;
+}
+
/**
* queue_spin_lock_slowpath - acquire the queue spinlock
* @lock: Pointer to queue spinlock structure
* @val: Current value of the queue spinlock 32-bit word
*
- * (queue tail, lock bit)
+ * (queue tail, pending bit, lock bit)
+ *
+ * fast : slow : unlock
+ *...
2014 Jun 17
5
[PATCH 03/11] qspinlock: Add pending bit
...nother cmpxchg in case
the unlocker has just unlocked itself.
So something like:
diff --git a/include/asm-generic/qspinlock.h b/include/asm-generic/qspinlock.h
index e8a7ae8..29cc9c7 100644
--- a/include/asm-generic/qspinlock.h
+++ b/include/asm-generic/qspinlock.h
@@ -75,11 +75,21 @@ extern void queue_spin_lock_slowpath(struct qspinlock *lock, u32 val);
*/
static __always_inline void queue_spin_lock(struct qspinlock *lock)
{
- u32 val;
+ u32 val, new;
val = atomic_cmpxchg(&lock->val, 0, _Q_LOCKED_VAL);
if (likely(val == 0))
return;
+
+ /* One more attempt - but if we fail mark it as pending. */...
2014 Jun 17
5
[PATCH 03/11] qspinlock: Add pending bit
...nother cmpxchg in case
the unlocker has just unlocked itself.
So something like:
diff --git a/include/asm-generic/qspinlock.h b/include/asm-generic/qspinlock.h
index e8a7ae8..29cc9c7 100644
--- a/include/asm-generic/qspinlock.h
+++ b/include/asm-generic/qspinlock.h
@@ -75,11 +75,21 @@ extern void queue_spin_lock_slowpath(struct qspinlock *lock, u32 val);
*/
static __always_inline void queue_spin_lock(struct qspinlock *lock)
{
- u32 val;
+ u32 val, new;
val = atomic_cmpxchg(&lock->val, 0, _Q_LOCKED_VAL);
if (likely(val == 0))
return;
+
+ /* One more attempt - but if we fail mark it as pending. */...
2014 Jun 15
0
[PATCH 03/11] qspinlock: Add pending bit
...dif /* __ASM_GENERIC_QSPINLOCK_TYPES_H */
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -83,24 +83,28 @@ static inline struct mcs_spinlock *decod
return per_cpu_ptr(&mcs_nodes[idx], cpu);
}
+#define _Q_LOCKED_PENDING_MASK (_Q_LOCKED_MASK | _Q_PENDING_MASK)
+
/**
* queue_spin_lock_slowpath - acquire the queue spinlock
* @lock: Pointer to queue spinlock structure
* @val: Current value of the queue spinlock 32-bit word
*
- * (queue tail, lock bit)
- *
- * fast : slow : unlock
- * :...
2015 Mar 16
19
[PATCH 0/9] qspinlock stuff -v15
Hi Waiman,
As promised; here is the paravirt stuff I did during the trip to BOS last week.
All the !paravirt patches are more or less the same as before (the only real
change is the copyright lines in the first patch).
The paravirt stuff is 'simple' and KVM only -- the Xen code was a little more
convoluted and I've no real way to test that but it should be stright fwd to
make work.
2015 Mar 16
19
[PATCH 0/9] qspinlock stuff -v15
Hi Waiman,
As promised; here is the paravirt stuff I did during the trip to BOS last week.
All the !paravirt patches are more or less the same as before (the only real
change is the copyright lines in the first patch).
The paravirt stuff is 'simple' and KVM only -- the Xen code was a little more
convoluted and I've no real way to test that but it should be stright fwd to
make work.
2014 Jun 15
28
[PATCH 00/11] qspinlock with paravirt support
Since Waiman seems incapable of doing simple things; here's my take on the
paravirt crap.
The first few patches are taken from Waiman's latest series, but the virt
support is completely new. Its primary aim is to not mess up the native code.
I've not stress tested it, but the virt and paravirt (kvm) cases boot on simple
smp guests. I've not done Xen, but the patch should be
2014 Jun 15
28
[PATCH 00/11] qspinlock with paravirt support
Since Waiman seems incapable of doing simple things; here's my take on the
paravirt crap.
The first few patches are taken from Waiman's latest series, but the virt
support is completely new. Its primary aim is to not mess up the native code.
I've not stress tested it, but the virt and paravirt (kvm) cases boot on simple
smp guests. I've not done Xen, but the patch should be
2014 Apr 17
0
[PATCH v9 03/19] qspinlock: Add pending bit
...pu_relax();
+
+ /*
+ * take ownership and clear the pending bit.
+ *
+ * *,1,0 -> *,0,1
+ */
+ for (;;) {
+ new = (val & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL;
+
+ old = atomic_cmpxchg(&lock->val, val, new);
+ if (old == val)
+ break;
+
+ val = old;
+ }
+ return 1;
+}
+
/**
* queue_spin_lock_slowpath - acquire the queue spinlock
* @lock: Pointer to queue spinlock structure
* @val: Current value of the queue spinlock 32-bit word
*
- * (queue tail, lock bit)
+ * (queue tail, pending bit, lock bit)
*
- * fast : slow : unlock
- *...
2014 May 07
0
[PATCH v10 08/19] qspinlock: Make a new qnode structure to support virtualization
...SK) >> _Q_TAIL_IDX_OFFSET;
- return per_cpu_ptr(&mcs_nodes[idx], cpu);
+ return per_cpu_ptr(&qnodes[idx], cpu);
}
#define _Q_LOCKED_PENDING_MASK (_Q_LOCKED_MASK | _Q_PENDING_MASK)
@@ -342,7 +351,7 @@ static inline int trylock_pending(struct qspinlock *lock, u32 *pval)
*/
void queue_spin_lock_slowpath(struct qspinlock *lock, u32 val)
{
- struct mcs_spinlock *prev, *next, *node;
+ struct qnode *prev, *next, *node;
u32 old, tail;
int idx;
@@ -351,13 +360,13 @@ void queue_spin_lock_slowpath(struct qspinlock *lock, u32 val)
if (trylock_pending(lock, &val))
return; /* Lock acquired */...
2015 Mar 16
0
[PATCH 3/9] qspinlock: Add pending bit
...dif /* __ASM_GENERIC_QSPINLOCK_TYPES_H */
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -94,24 +94,28 @@ static inline struct mcs_spinlock *decod
return per_cpu_ptr(&mcs_nodes[idx], cpu);
}
+#define _Q_LOCKED_PENDING_MASK (_Q_LOCKED_MASK | _Q_PENDING_MASK)
+
/**
* queue_spin_lock_slowpath - acquire the queue spinlock
* @lock: Pointer to queue spinlock structure
* @val: Current value of the queue spinlock 32-bit word
*
- * (queue tail, lock value)
- *
- * fast : slow : unlock
- * :...
2015 May 04
1
[PATCH v16 08/14] pvqspinlock: Implement simple paravirt support for the qspinlock
..._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_spin_lock_slowpath native_queue_spin_lock_slowpath
+#endif
+
+#endif /* _GEN_PV_LOCK_SLOWPATH */
+
/**
* queue_spin_lock_slowpath - acquire the queue spinlock
* @lock: Pointer to queue spinlock structure
@@ -249,6 +286,9 @@ void queue_spin_lock_slowpath(struct qsp
BUILD_BUG_ON(CONFIG_NR_CPUS >= (1U <&l...
2015 May 04
1
[PATCH v16 08/14] pvqspinlock: Implement simple paravirt support for the qspinlock
..._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_spin_lock_slowpath native_queue_spin_lock_slowpath
+#endif
+
+#endif /* _GEN_PV_LOCK_SLOWPATH */
+
/**
* queue_spin_lock_slowpath - acquire the queue spinlock
* @lock: Pointer to queue spinlock structure
@@ -249,6 +286,9 @@ void queue_spin_lock_slowpath(struct qsp
BUILD_BUG_ON(CONFIG_NR_CPUS >= (1U <&l...
2015 Mar 18
2
[PATCH 8/9] qspinlock: Generic paravirt support
...++++++++++++++++++++++++++++++++++
> 3 files changed, 248 insertions(+), 1 deletion(-)
>
> --- a/include/asm-generic/qspinlock.h
> +++ b/include/asm-generic/qspinlock.h
> @@ -118,6 +118,9 @@ static __always_inline bool virt_queue_s
> }
> #endif
>
> +extern void __pv_queue_spin_lock_slowpath(struct qspinlock *lock, u32 val);
> +extern void __pv_queue_spin_unlock(struct qspinlock *lock);
> +
> /*
> * Initializier
> */
> --- a/kernel/locking/qspinlock.c
> +++ b/kernel/locking/qspinlock.c
> @@ -18,6 +18,9 @@
> * Authors: Waiman Long<waiman.long at...
2015 Mar 18
2
[PATCH 8/9] qspinlock: Generic paravirt support
...++++++++++++++++++++++++++++++++++
> 3 files changed, 248 insertions(+), 1 deletion(-)
>
> --- a/include/asm-generic/qspinlock.h
> +++ b/include/asm-generic/qspinlock.h
> @@ -118,6 +118,9 @@ static __always_inline bool virt_queue_s
> }
> #endif
>
> +extern void __pv_queue_spin_lock_slowpath(struct qspinlock *lock, u32 val);
> +extern void __pv_queue_spin_unlock(struct qspinlock *lock);
> +
> /*
> * Initializier
> */
> --- a/kernel/locking/qspinlock.c
> +++ b/kernel/locking/qspinlock.c
> @@ -18,6 +18,9 @@
> * Authors: Waiman Long<waiman.long at...