diff options
| -rw-r--r-- | arch/x86/Kconfig | 13 | ||||
| -rw-r--r-- | arch/x86/include/asm/paravirt.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/spinlock.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/Makefile | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/paravirt.c | 2 | ||||
| -rw-r--r-- | arch/x86/xen/Makefile | 5 | ||||
| -rw-r--r-- | arch/x86/xen/xen-ops.h | 19 |
7 files changed, 38 insertions, 10 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index df9e885eee14..a6efe0a2e9ae 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -498,6 +498,19 @@ config PARAVIRT over full virtualization. However, when run without a hypervisor the kernel is theoretically slower and slightly larger. +config PARAVIRT_SPINLOCKS + bool "Paravirtualization layer for spinlocks" + depends on PARAVIRT && SMP && EXPERIMENTAL + ---help--- + Paravirtualized spinlocks allow a pvops backend to replace the + spinlock implementation with something virtualization-friendly + (for example, block the virtual CPU rather than spinning). + + Unfortunately the downside is an up to 5% performance hit on + native kernels, with various workloads. + + If you are unsure how to answer this question, answer N. + config PARAVIRT_CLOCK bool default n diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 378e3691c08c..a53da004e08e 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -1443,7 +1443,7 @@ u64 _paravirt_ident_64(u64); #define paravirt_nop ((void *)_paravirt_nop) -#ifdef CONFIG_SMP +#if defined(CONFIG_SMP) && defined(CONFIG_PARAVIRT_SPINLOCKS) static inline int __raw_spin_is_locked(struct raw_spinlock *lock) { diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index e5e6caffec87..b7e5db876399 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -172,7 +172,7 @@ static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) return (((tmp >> TICKET_SHIFT) - tmp) & ((1 << TICKET_SHIFT) - 1)) > 1; } -#ifndef CONFIG_PARAVIRT +#ifndef CONFIG_PARAVIRT_SPINLOCKS static inline int __raw_spin_is_locked(raw_spinlock_t *lock) { @@ -206,7 +206,7 @@ static __always_inline void __raw_spin_lock_flags(raw_spinlock_t *lock, __raw_spin_lock(lock); } -#endif +#endif /* CONFIG_PARAVIRT_SPINLOCKS */ static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock) { diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 145cce75cda7..88d1bfc847d3 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -89,7 +89,8 @@ obj-$(CONFIG_DEBUG_NX_TEST) += test_nx.o obj-$(CONFIG_VMI) += vmi_32.o vmiclock_32.o obj-$(CONFIG_KVM_GUEST) += kvm.o obj-$(CONFIG_KVM_CLOCK) += kvmclock.o -obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o paravirt-spinlocks.o +obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt_patch_$(BITS).o +obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= paravirt-spinlocks.o obj-$(CONFIG_PARAVIRT_CLOCK) += pvclock.o obj-$(CONFIG_PCSPKR_PLATFORM) += pcspeaker.o diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 8e45f4464880..9faf43bea336 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -134,7 +134,9 @@ static void *get_call_destination(u8 type) .pv_irq_ops = pv_irq_ops, .pv_apic_ops = pv_apic_ops, .pv_mmu_ops = pv_mmu_ops, +#ifdef CONFIG_PARAVIRT_SPINLOCKS .pv_lock_ops = pv_lock_ops, +#endif }; return *((void **)&tmpl + type); } diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile index 3b767d03fd6a..172438f86a02 100644 --- a/arch/x86/xen/Makefile +++ b/arch/x86/xen/Makefile @@ -9,5 +9,6 @@ obj-y := enlighten.o setup.o multicalls.o mmu.o irq.o \ time.o xen-asm.o xen-asm_$(BITS).o \ grant-table.o suspend.o -obj-$(CONFIG_SMP) += smp.o spinlock.o -obj-$(CONFIG_XEN_DEBUG_FS) += debugfs.o
\ No newline at end of file +obj-$(CONFIG_SMP) += smp.o +obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o +obj-$(CONFIG_XEN_DEBUG_FS) += debugfs.o diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 20139464943c..ca6596b05d53 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -62,15 +62,26 @@ void xen_setup_vcpu_info_placement(void); #ifdef CONFIG_SMP void xen_smp_init(void); -void __init xen_init_spinlocks(void); -__cpuinit void xen_init_lock_cpu(int cpu); -void xen_uninit_lock_cpu(int cpu); - extern cpumask_var_t xen_cpu_initialized_map; #else static inline void xen_smp_init(void) {} #endif +#ifdef CONFIG_PARAVIRT_SPINLOCKS +void __init xen_init_spinlocks(void); +__cpuinit void xen_init_lock_cpu(int cpu); +void xen_uninit_lock_cpu(int cpu); +#else +static inline void xen_init_spinlocks(void) +{ +} +static inline void xen_init_lock_cpu(int cpu) +{ +} +static inline void xen_uninit_lock_cpu(int cpu) +{ +} +#endif /* Declare an asm function, along with symbols needed to make it inlineable */ |