Displaying 4 results from an estimated 4 matches for "0e6740a".
2014 Mar 12
0
[PATCH v6 05/11] pvqspinlock, x86: Allow unfair spinlock in a PV guest
.... However, there is a possibility of lock starvation
+ on a heavily contended lock especially in a large guest
+ with many virtual CPUs.
+
source "arch/x86/xen/Kconfig"
config KVM_GUEST
diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index 7f3129c..0e6740a 100644
--- a/arch/x86/include/asm/qspinlock.h
+++ b/arch/x86/include/asm/qspinlock.h
@@ -51,4 +51,76 @@ static inline void queue_spin_unlock(struct qspinlock *lock)
#include <asm-generic/qspinlock.h>
+#ifdef CONFIG_PARAVIRT_UNFAIR_LOCKS
+/**
+ * queue_spin_lock_unfair - acquire a queue s...
2014 Mar 12
0
[PATCH RFC v6 09/11] pvqspinlock, x86: Add qspinlock para-virtualization support
...pv_qvars *pv)
+{
+ if (pv->cpustate != PV_CPU_HALTED)
+ return;
+ ACCESS_ONCE(pv->cpustate) = PV_CPU_KICKED;
+ __queue_kick_cpu(pv->mycpu, PV_KICK_QUEUE_HEAD);
+}
+
+#endif /* _ASM_X86_PVQSPINLOCK_H */
diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h
index 0e6740a..4f85c33 100644
--- a/arch/x86/include/asm/qspinlock.h
+++ b/arch/x86/include/asm/qspinlock.h
@@ -38,7 +38,11 @@ union arch_qspinlock {
* that the clearing the lock bit is done ASAP without artificial delay
* due to compiler optimization.
*/
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+static __always_...
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