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With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V2: - use static key instead of making virt_spin_lock() a pvops function Juergen Gross

With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V2: - use static key instead of making virt_spin_lock() a pvops function Juergen Gross

...inline bool virt_spin_lock(struct qspinlock *lock) return true; } +#else +static inline void native_pv_lock_init(void) +{ +} #endif /* CONFIG_PARAVIRT */ #include <asm-generic/qspinlock.h> diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 8f2d1c9d43a8..2fc65ddea40d 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -42,3 +42,9 @@ struct pv_lock_ops pv_lock_ops = { #endif /* SMP */ }; EXPORT_SYMBOL(pv_lock_ops); + +void __init native_pv_lock_init(void) +{ + if (!static_cpu_has(X86_FEATURE_HYPERVISOR...

...gt; return true; > } > +#else > +static inline void native_pv_lock_init(void) > +{ > +} > #endif /* CONFIG_PARAVIRT */ > > #include <asm-generic/qspinlock.h> > diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c > index 8f2d1c9d43a8..2fc65ddea40d 100644 > --- a/arch/x86/kernel/paravirt-spinlocks.c > +++ b/arch/x86/kernel/paravirt-spinlocks.c > @@ -42,3 +42,9 @@ struct pv_lock_ops pv_lock_ops = { > #endif /* SMP */ > }; > EXPORT_SYMBOL(pv_lock_ops); > + > +void __init native_pv_lock_init(void) > +{...

...gt; return true; > } > +#else > +static inline void native_pv_lock_init(void) > +{ > +} > #endif /* CONFIG_PARAVIRT */ > > #include <asm-generic/qspinlock.h> > diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c > index 8f2d1c9d43a8..2fc65ddea40d 100644 > --- a/arch/x86/kernel/paravirt-spinlocks.c > +++ b/arch/x86/kernel/paravirt-spinlocks.c > @@ -42,3 +42,9 @@ struct pv_lock_ops pv_lock_ops = { > #endif /* SMP */ > }; > EXPORT_SYMBOL(pv_lock_ops); > + > +void __init native_pv_lock_init(void) > +{...

With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V3: - remove test for hypervisor environment from virt_spin_lock(9 as suggested by

With virt_spin_lock() being guarded by a static key the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. V3: - remove test for hypervisor environment from virt_spin_lock(9 as suggested by

With virt_spin_lock() being a pvops function the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. Juergen Gross (4): paravirt: add generic _paravirt_false() function paravirt: switch

With virt_spin_lock() being a pvops function the bare metal case can be optimized by patching the call away completely. In case a kernel running as a guest it can decide whether to use paravitualized spinlocks, the current fallback to the unfair test-and-set scheme, or to mimic the bare metal behavior. Juergen Gross (4): paravirt: add generic _paravirt_false() function paravirt: switch