* [PATCH v2 1/6] qspinlock: powerpc support qspinlock
2016-05-17 7:49 [PATCH v3 0/6] powerpc use pv-qpsinlock instead of spinlock Pan Xinhui
@ 2016-05-17 7:49 ` Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 2/6] powerpc: pseries/Kconfig: qspinlock build config Pan Xinhui
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Pan Xinhui @ 2016-05-17 7:49 UTC (permalink / raw)
To: linux-kernel, virtualization, linuxppc-dev
Cc: benh, paulus, mpe, peterz, mingo, paulmck, waiman.long, mnipxh,
boqun.feng, Pan Xinhui
Base code to enable qspinlock on powerpc. this patch add some #ifdef
here and there. Although there is no paravirt related code, we can
successfully build a qspinlock kernel after apply this patch.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/qspinlock.h | 22 ++++++++++++++++++++++
arch/powerpc/include/asm/spinlock.h | 27 +++++++++++++++------------
arch/powerpc/include/asm/spinlock_types.h | 4 ++++
arch/powerpc/lib/locks.c | 4 ++++
4 files changed, 45 insertions(+), 12 deletions(-)
create mode 100644 arch/powerpc/include/asm/qspinlock.h
diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h
new file mode 100644
index 0000000..5883954
--- /dev/null
+++ b/arch/powerpc/include/asm/qspinlock.h
@@ -0,0 +1,22 @@
+#ifndef _ASM_POWERPC_QSPINLOCK_H
+#define _ASM_POWERPC_QSPINLOCK_H
+
+#include <asm-generic/qspinlock_types.h>
+
+#define SPIN_THRESHOLD (1 << 15)
+#define queued_spin_unlock queued_spin_unlock
+
+static inline void native_queued_spin_unlock(struct qspinlock *lock)
+{
+ /* no load/store can be across the unlock()*/
+ smp_store_release((u8 *)lock, 0);
+}
+
+static inline void queued_spin_unlock(struct qspinlock *lock)
+{
+ native_queued_spin_unlock(lock);
+}
+
+#include <asm-generic/qspinlock.h>
+
+#endif /* _ASM_POWERPC_QSPINLOCK_H */
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index 523673d..4359ee6 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -52,6 +52,20 @@
#define SYNC_IO
#endif
+#if defined(CONFIG_PPC_SPLPAR)
+/* We only yield to the hypervisor if we are in shared processor mode */
+#define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr))
+extern void __spin_yield(arch_spinlock_t *lock);
+extern void __rw_yield(arch_rwlock_t *lock);
+#else /* SPLPAR */
+#define __spin_yield(x) barrier()
+#define __rw_yield(x) barrier()
+#define SHARED_PROCESSOR 0
+#endif
+
+#ifdef CONFIG_QUEUED_SPINLOCKS
+#include <asm/qspinlock.h>
+#else
static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)
{
return lock.slock == 0;
@@ -106,18 +120,6 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock)
* held. Conveniently, we have a word in the paca that holds this
* value.
*/
-
-#if defined(CONFIG_PPC_SPLPAR)
-/* We only yield to the hypervisor if we are in shared processor mode */
-#define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr))
-extern void __spin_yield(arch_spinlock_t *lock);
-extern void __rw_yield(arch_rwlock_t *lock);
-#else /* SPLPAR */
-#define __spin_yield(x) barrier()
-#define __rw_yield(x) barrier()
-#define SHARED_PROCESSOR 0
-#endif
-
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
CLEAR_IO_SYNC;
@@ -169,6 +171,7 @@ extern void arch_spin_unlock_wait(arch_spinlock_t *lock);
do { while (arch_spin_is_locked(lock)) cpu_relax(); } while (0)
#endif
+#endif /* !CONFIG_QUEUED_SPINLOCKS */
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
diff --git a/arch/powerpc/include/asm/spinlock_types.h b/arch/powerpc/include/asm/spinlock_types.h
index 2351adc..bd7144e 100644
--- a/arch/powerpc/include/asm/spinlock_types.h
+++ b/arch/powerpc/include/asm/spinlock_types.h
@@ -5,11 +5,15 @@
# error "please don't include this file directly"
#endif
+#ifdef CONFIG_QUEUED_SPINLOCKS
+#include <asm-generic/qspinlock_types.h>
+#else
typedef struct {
volatile unsigned int slock;
} arch_spinlock_t;
#define __ARCH_SPIN_LOCK_UNLOCKED { 0 }
+#endif
typedef struct {
volatile signed int lock;
diff --git a/arch/powerpc/lib/locks.c b/arch/powerpc/lib/locks.c
index f7deebd..a9ebd71 100644
--- a/arch/powerpc/lib/locks.c
+++ b/arch/powerpc/lib/locks.c
@@ -23,6 +23,7 @@
#include <asm/hvcall.h>
#include <asm/smp.h>
+#ifndef CONFIG_QUEUED_SPINLOCKS
void __spin_yield(arch_spinlock_t *lock)
{
unsigned int lock_value, holder_cpu, yield_count;
@@ -42,6 +43,7 @@ void __spin_yield(arch_spinlock_t *lock)
get_hard_smp_processor_id(holder_cpu), yield_count);
}
EXPORT_SYMBOL_GPL(__spin_yield);
+#endif
/*
* Waiting for a read lock or a write lock on a rwlock...
@@ -69,6 +71,7 @@ void __rw_yield(arch_rwlock_t *rw)
}
#endif
+#ifndef CONFIG_QUEUED_SPINLOCKS
void arch_spin_unlock_wait(arch_spinlock_t *lock)
{
smp_mb();
@@ -84,3 +87,4 @@ void arch_spin_unlock_wait(arch_spinlock_t *lock)
}
EXPORT_SYMBOL(arch_spin_unlock_wait);
+#endif
--
1.9.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 2/6] powerpc: pseries/Kconfig: qspinlock build config
2016-05-17 7:49 [PATCH v3 0/6] powerpc use pv-qpsinlock instead of spinlock Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 1/6] qspinlock: powerpc support qspinlock Pan Xinhui
@ 2016-05-17 7:49 ` Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 3/6] powerpc: lib/locks.c: cpu yield/wake helper function Pan Xinhui
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Pan Xinhui @ 2016-05-17 7:49 UTC (permalink / raw)
To: linux-kernel, virtualization, linuxppc-dev
Cc: benh, paulus, mpe, peterz, mingo, paulmck, waiman.long, mnipxh,
boqun.feng, Pan Xinhui
pseries will use qspinlock by default.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
arch/powerpc/platforms/pseries/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index bec90fb..f669323 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -21,6 +21,7 @@ config PPC_PSERIES
select HOTPLUG_CPU if SMP
select ARCH_RANDOM
select PPC_DOORBELL
+ select ARCH_USE_QUEUED_SPINLOCKS
default y
config PPC_SPLPAR
--
1.9.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 3/6] powerpc: lib/locks.c: cpu yield/wake helper function
2016-05-17 7:49 [PATCH v3 0/6] powerpc use pv-qpsinlock instead of spinlock Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 1/6] qspinlock: powerpc support qspinlock Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 2/6] powerpc: pseries/Kconfig: qspinlock build config Pan Xinhui
@ 2016-05-17 7:49 ` Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 4/6] pv-qspinlock: powerpc support pv-qspinlock Pan Xinhui
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Pan Xinhui @ 2016-05-17 7:49 UTC (permalink / raw)
To: linux-kernel, virtualization, linuxppc-dev
Cc: benh, paulus, mpe, peterz, mingo, paulmck, waiman.long, mnipxh,
boqun.feng, Pan Xinhui
pv-qspinlock core has pv_wait/pv_kick which will give a better
performace by yielding and kicking cpu at some cases.
lets support them by adding two corresponding helper functions.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/spinlock.h | 4 ++++
arch/powerpc/lib/locks.c | 32 ++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index 4359ee6..3b65372 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -56,9 +56,13 @@
/* We only yield to the hypervisor if we are in shared processor mode */
#define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr))
extern void __spin_yield(arch_spinlock_t *lock);
+extern void __spin_yield_cpu(int cpu);
+extern void __spin_wake_cpu(int cpu);
extern void __rw_yield(arch_rwlock_t *lock);
#else /* SPLPAR */
#define __spin_yield(x) barrier()
+#define __spin_yield_cpu(x) barrier()
+#define __spin_wake_cpu(x) barrier()
#define __rw_yield(x) barrier()
#define SHARED_PROCESSOR 0
#endif
diff --git a/arch/powerpc/lib/locks.c b/arch/powerpc/lib/locks.c
index a9ebd71..4109679a 100644
--- a/arch/powerpc/lib/locks.c
+++ b/arch/powerpc/lib/locks.c
@@ -23,6 +23,38 @@
#include <asm/hvcall.h>
#include <asm/smp.h>
+void __spin_yield_cpu(int cpu)
+{
+ unsigned int holder_cpu = cpu, yield_count;
+
+ if (cpu == -1) {
+ plpar_hcall_norets(H_CEDE);
+ return;
+ }
+ BUG_ON(holder_cpu >= nr_cpu_ids);
+ yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count);
+ if ((yield_count & 1) == 0)
+ return; /* virtual cpu is currently running */
+ rmb();
+ plpar_hcall_norets(H_CONFER,
+ get_hard_smp_processor_id(holder_cpu), yield_count);
+}
+EXPORT_SYMBOL_GPL(__spin_yield_cpu);
+
+void __spin_wake_cpu(int cpu)
+{
+ unsigned int holder_cpu = cpu, yield_count;
+
+ BUG_ON(holder_cpu >= nr_cpu_ids);
+ yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count);
+ if ((yield_count & 1) == 0)
+ return; /* virtual cpu is currently running */
+ rmb();
+ plpar_hcall_norets(H_PROD,
+ get_hard_smp_processor_id(holder_cpu));
+}
+EXPORT_SYMBOL_GPL(__spin_wake_cpu);
+
#ifndef CONFIG_QUEUED_SPINLOCKS
void __spin_yield(arch_spinlock_t *lock)
{
--
1.9.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 4/6] pv-qspinlock: powerpc support pv-qspinlock
2016-05-17 7:49 [PATCH v3 0/6] powerpc use pv-qpsinlock instead of spinlock Pan Xinhui
` (2 preceding siblings ...)
2016-05-17 7:49 ` [PATCH v2 3/6] powerpc: lib/locks.c: cpu yield/wake helper function Pan Xinhui
@ 2016-05-17 7:49 ` Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 5/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 6/6] powerpc: pseries: pv-qspinlock build config/make Pan Xinhui
5 siblings, 0 replies; 7+ messages in thread
From: Pan Xinhui @ 2016-05-17 7:49 UTC (permalink / raw)
To: linux-kernel, virtualization, linuxppc-dev
Cc: benh, paulus, mpe, peterz, mingo, paulmck, waiman.long, mnipxh,
boqun.feng, Pan Xinhui
As we need let pv-qspinlock-kernel run on all environment which might
have no powervm, we should runtime choose which qspinlock version to
use. The default pv-qspinlock use native version. pv_lock initialization
should be done in bootstage with irq disabled. And if possible, restore
pv_lock_ops callbacks to pv version.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/qspinlock.h | 17 +++++++++
arch/powerpc/include/asm/qspinlock_paravirt.h | 38 +++++++++++++++++++
.../powerpc/include/asm/qspinlock_paravirt_types.h | 13 +++++++
arch/powerpc/kernel/paravirt.c | 44 ++++++++++++++++++++++
arch/powerpc/platforms/pseries/setup.c | 5 +++
5 files changed, 117 insertions(+)
create mode 100644 arch/powerpc/include/asm/qspinlock_paravirt.h
create mode 100644 arch/powerpc/include/asm/qspinlock_paravirt_types.h
create mode 100644 arch/powerpc/kernel/paravirt.c
diff --git a/arch/powerpc/include/asm/qspinlock.h b/arch/powerpc/include/asm/qspinlock.h
index 5883954..4728f6e 100644
--- a/arch/powerpc/include/asm/qspinlock.h
+++ b/arch/powerpc/include/asm/qspinlock.h
@@ -12,10 +12,27 @@ static inline void native_queued_spin_unlock(struct qspinlock *lock)
smp_store_release((u8 *)lock, 0);
}
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+
+#define __ARCH_NEED_PV_HASH_LOOKUP
+
+#include <asm/qspinlock_paravirt.h>
+
+static inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
+{
+ pv_queued_spin_lock(lock, val);
+}
+
+static inline void queued_spin_unlock(struct qspinlock *lock)
+{
+ pv_queued_spin_unlock(lock);
+}
+#else
static inline void queued_spin_unlock(struct qspinlock *lock)
{
native_queued_spin_unlock(lock);
}
+#endif
#include <asm-generic/qspinlock.h>
diff --git a/arch/powerpc/include/asm/qspinlock_paravirt.h b/arch/powerpc/include/asm/qspinlock_paravirt.h
new file mode 100644
index 0000000..cd17a79
--- /dev/null
+++ b/arch/powerpc/include/asm/qspinlock_paravirt.h
@@ -0,0 +1,38 @@
+#ifndef CONFIG_PARAVIRT_SPINLOCKS
+#error "do not include this file"
+#endif
+
+#ifndef _ASM_QSPINLOCK_PARAVIRT_H
+#define _ASM_QSPINLOCK_PARAVIRT_H
+
+#include <asm/qspinlock_paravirt_types.h>
+
+extern void pv_lock_init(void);
+extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_init_lock_hash(void);
+extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
+extern void __pv_queued_spin_unlock(struct qspinlock *lock);
+
+static inline void pv_queued_spin_lock(struct qspinlock *lock, u32 val)
+{
+ CLEAR_IO_SYNC;
+ pv_lock_op.lock(lock, val);
+}
+
+static inline void pv_queued_spin_unlock(struct qspinlock *lock)
+{
+ SYNC_IO;
+ pv_lock_op.unlock(lock);
+}
+
+static inline void pv_wait(u8 *ptr, u8 val, int lockcpu)
+{
+ pv_lock_op.wait(ptr, val, lockcpu);
+}
+
+static inline void pv_kick(int cpu)
+{
+ pv_lock_op.kick(cpu);
+}
+
+#endif
diff --git a/arch/powerpc/include/asm/qspinlock_paravirt_types.h b/arch/powerpc/include/asm/qspinlock_paravirt_types.h
new file mode 100644
index 0000000..e1fdeb0
--- /dev/null
+++ b/arch/powerpc/include/asm/qspinlock_paravirt_types.h
@@ -0,0 +1,13 @@
+#ifndef _ASM_QSPINLOCK_PARAVIRT_TYPES_H
+#define _ASM_QSPINLOCK_PARAVIRT_TYPES_H
+
+struct pv_lock_ops {
+ void (*lock)(struct qspinlock *lock, u32 val);
+ void (*unlock)(struct qspinlock *lock);
+ void (*wait)(u8 *ptr, u8 val, int cpu);
+ void (*kick)(int cpu);
+};
+
+extern struct pv_lock_ops pv_lock_op;
+
+#endif
diff --git a/arch/powerpc/kernel/paravirt.c b/arch/powerpc/kernel/paravirt.c
new file mode 100644
index 0000000..ea56c5f
--- /dev/null
+++ b/arch/powerpc/kernel/paravirt.c
@@ -0,0 +1,44 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/spinlock.h>
+
+static void __native_queued_spin_unlock(struct qspinlock *lock)
+{
+ native_queued_spin_unlock(lock);
+}
+
+static void __pv_wait(u8 *ptr, u8 val, int cpu)
+{
+ HMT_low();
+ __spin_yield_cpu(cpu);
+ HMT_medium();
+}
+
+static void __pv_kick(int cpu)
+{
+ __spin_wake_cpu(cpu);
+}
+
+struct pv_lock_ops pv_lock_op = {
+ .lock = native_queued_spin_lock_slowpath,
+ .unlock = __native_queued_spin_unlock,
+ .wait = NULL,
+ .kick = NULL,
+};
+EXPORT_SYMBOL(pv_lock_op);
+
+void __init pv_lock_init(void)
+{
+ if (SHARED_PROCESSOR) {
+ __pv_init_lock_hash();
+ pv_lock_op.lock = __pv_queued_spin_lock_slowpath;
+ pv_lock_op.unlock = __pv_queued_spin_unlock;
+ pv_lock_op.wait = __pv_wait;
+ pv_lock_op.kick = __pv_kick;
+ }
+}
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 6e944fc..c9f056e 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -547,6 +547,11 @@ static void __init pSeries_setup_arch(void)
"%ld\n", rc);
}
}
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+ pv_lock_init();
+#endif
+
}
static int __init pSeries_init_panel(void)
--
1.9.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 5/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock
2016-05-17 7:49 [PATCH v3 0/6] powerpc use pv-qpsinlock instead of spinlock Pan Xinhui
` (3 preceding siblings ...)
2016-05-17 7:49 ` [PATCH v2 4/6] pv-qspinlock: powerpc support pv-qspinlock Pan Xinhui
@ 2016-05-17 7:49 ` Pan Xinhui
2016-05-17 7:49 ` [PATCH v2 6/6] powerpc: pseries: pv-qspinlock build config/make Pan Xinhui
5 siblings, 0 replies; 7+ messages in thread
From: Pan Xinhui @ 2016-05-17 7:49 UTC (permalink / raw)
To: linux-kernel, virtualization, linuxppc-dev
Cc: benh, paulus, mpe, peterz, mingo, paulmck, waiman.long, mnipxh,
boqun.feng, Pan Xinhui
cmpxchg_release is lighter, we can gain a better performace then.
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
kernel/locking/qspinlock_paravirt.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index a5b1248..2bbffe4 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -614,7 +614,7 @@ __visible void __pv_queued_spin_unlock(struct qspinlock *lock)
* unhash. Otherwise it would be possible to have multiple @lock
* entries, which would be BAD.
*/
- locked = cmpxchg(&l->locked, _Q_LOCKED_VAL, 0);
+ locked = cmpxchg_release(&l->locked, _Q_LOCKED_VAL, 0);
if (likely(locked == _Q_LOCKED_VAL))
return;
--
1.9.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v2 6/6] powerpc: pseries: pv-qspinlock build config/make
2016-05-17 7:49 [PATCH v3 0/6] powerpc use pv-qpsinlock instead of spinlock Pan Xinhui
` (4 preceding siblings ...)
2016-05-17 7:49 ` [PATCH v2 5/6] pv-qspinlock: use cmpxchg_release in __pv_queued_spin_unlock Pan Xinhui
@ 2016-05-17 7:49 ` Pan Xinhui
5 siblings, 0 replies; 7+ messages in thread
From: Pan Xinhui @ 2016-05-17 7:49 UTC (permalink / raw)
To: linux-kernel, virtualization, linuxppc-dev
Cc: benh, paulus, mpe, peterz, mingo, paulmck, waiman.long, mnipxh,
boqun.feng, Pan Xinhui
pseries can use pv-qspinlock.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
---
arch/powerpc/kernel/Makefile | 1 +
arch/powerpc/platforms/pseries/Kconfig | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 2da380f..ae7c2f1 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_PPC_970_NAP) += idle_power4.o
obj-$(CONFIG_PPC_P7_NAP) += idle_power7.o
procfs-y := proc_powerpc.o
obj-$(CONFIG_PROC_FS) += $(procfs-y)
+obj-$(CONFIG_PARAVIRT_SPINLOCKS) += paravirt.o
rtaspci-$(CONFIG_PPC64)-$(CONFIG_PCI) := rtas_pci.o
obj-$(CONFIG_PPC_RTAS) += rtas.o rtas-rtc.o $(rtaspci-y-y)
obj-$(CONFIG_PPC_RTAS_DAEMON) += rtasd.o
diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index f669323..46632e4 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -128,3 +128,11 @@ config HV_PERF_CTRS
systems. 24x7 is available on Power 8 systems.
If unsure, select Y.
+
+config PARAVIRT_SPINLOCKS
+ bool "Paravirtialization support for qspinlock"
+ depends on PPC_SPLPAR && QUEUED_SPINLOCKS
+ default y
+ help
+ If platform supports virtualization, for example PowerVM, this option
+ can let guest have a better performace.
--
1.9.1
^ permalink raw reply related [flat|nested] 7+ messages in thread