search for: __native_vcpu_is_preempted

..._is_preempted; } #endif /* CONFIG_PARAVIRT_SPINLOCKS */ diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6259327..da050bc 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -24,12 +24,10 @@ __visible bool __native_vcpu_is_preempted(int cpu) { return false; } -PV_CALLEE_SAVE_REGS_THUNK(__native_vcpu_is_preempted); bool pv_is_native_vcpu_is_preempted(void) { - return pv_lock_ops.vcpu_is_preempted.func == - __raw_callee_save___native_vcpu_is_preempted; + return pv_lock_ops.vcpu_is_preempted == __native_vcpu_is_preempted...

..._is_preempted; } #endif /* CONFIG_PARAVIRT_SPINLOCKS */ diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6259327..da050bc 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -24,12 +24,10 @@ __visible bool __native_vcpu_is_preempted(int cpu) { return false; } -PV_CALLEE_SAVE_REGS_THUNK(__native_vcpu_is_preempted); bool pv_is_native_vcpu_is_preempted(void) { - return pv_lock_ops.vcpu_is_preempted.func == - __raw_callee_save___native_vcpu_is_preempted; + return pv_lock_ops.vcpu_is_preempted == __native_vcpu_is_preempted...

...s to exploit KVM_FEATURE_PV_UNHALT if present. */ @@ -620,6 +616,12 @@ void __init kvm_spinlock_init(void) pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock); pv_lock_ops.wait = kvm_wait; pv_lock_ops.kick = kvm_kick_cpu; + pv_lock_ops.vcpu_is_preempted = PV_CALLEE_SAVE(__native_vcpu_is_preempted); + + if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { + pv_lock_ops.vcpu_is_preempted = + PV_CALLEE_SAVE(__kvm_vcpu_is_preempted); + } } static __init int kvm_spinlock_init_jump(void) --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -12,7 +12,6 @@...

...s to exploit KVM_FEATURE_PV_UNHALT if present. */ @@ -620,6 +616,12 @@ void __init kvm_spinlock_init(void) pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock); pv_lock_ops.wait = kvm_wait; pv_lock_ops.kick = kvm_kick_cpu; + pv_lock_ops.vcpu_is_preempted = PV_CALLEE_SAVE(__native_vcpu_is_preempted); + + if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { + pv_lock_ops.vcpu_is_preempted = + PV_CALLEE_SAVE(__kvm_vcpu_is_preempted); + } } static __init int kvm_spinlock_init_jump(void) --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -12,7 +12,6 @@...

..._is_preempted; } #endif /* CONFIG_PARAVIRT_SPINLOCKS */ diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6259327..da050bc 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -24,12 +24,10 @@ __visible bool __native_vcpu_is_preempted(int cpu) { return false; } -PV_CALLEE_SAVE_REGS_THUNK(__native_vcpu_is_preempted); bool pv_is_native_vcpu_is_preempted(void) { - return pv_lock_ops.vcpu_is_preempted.func == - __raw_callee_save___native_vcpu_is_preempted; + return pv_lock_ops.vcpu_is_preempted == __native_vcpu_is_preempted...

..._is_preempted; } #endif /* CONFIG_PARAVIRT_SPINLOCKS */ diff --git a/arch/x86/kernel/paravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6259327..da050bc 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -24,12 +24,10 @@ __visible bool __native_vcpu_is_preempted(int cpu) { return false; } -PV_CALLEE_SAVE_REGS_THUNK(__native_vcpu_is_preempted); bool pv_is_native_vcpu_is_preempted(void) { - return pv_lock_ops.vcpu_is_preempted.func == - __raw_callee_save___native_vcpu_is_preempted; + return pv_lock_ops.vcpu_is_preempted == __native_vcpu_is_preempted...

...HALT if present. > */ > @@ -620,6 +616,12 @@ void __init kvm_spinlock_init(void) > pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock); > pv_lock_ops.wait = kvm_wait; > pv_lock_ops.kick = kvm_kick_cpu; > + pv_lock_ops.vcpu_is_preempted = PV_CALLEE_SAVE(__native_vcpu_is_preempted); > + > + if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { > + pv_lock_ops.vcpu_is_preempted = > + PV_CALLEE_SAVE(__kvm_vcpu_is_preempted); > + } > } > > static __init int kvm_spinlock_init_jump(void) > --- a/arch/x86/kernel/paravirt-spinlocks.c > +++ b/arch/x8...

...ol (*vcpu_is_preempted)(int cpu); +}; + struct paravirt_patch_template { struct pv_time_ops time; + struct pv_lock_ops lock; }; extern struct paravirt_patch_template pv_ops; @@ -24,6 +29,13 @@ static inline u64 paravirt_steal_clock(int cpu) int __init pv_time_init(void); +__visible bool __native_vcpu_is_preempted(int cpu); + +static inline bool pv_vcpu_is_preempted(int cpu) +{ + return pv_ops.lock.vcpu_is_preempted(cpu); +} + #else #define pv_time_init() do {} while (0) diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index b093b287babf..45ff1b2949a6 100644 --- a/arch/a...

...aravirt-spinlocks.c b/arch/x86/kernel/paravirt-spinlocks.c index 6259327..8f2d1c9 100644 --- a/arch/x86/kernel/paravirt-spinlocks.c +++ b/arch/x86/kernel/paravirt-spinlocks.c @@ -20,7 +20,7 @@ bool pv_is_native_spin_unlock(void) __raw_callee_save___native_queued_spin_unlock; } -__visible bool __native_vcpu_is_preempted(int cpu) +__visible bool __native_vcpu_is_preempted(long cpu) { return false; } -- 1.8.3.1

v3->v4: - Fix x86-32 build error. v2->v3: - Provide an optimized __raw_callee_save___kvm_vcpu_is_preempted() in assembly as suggested by PeterZ. - Add a new patch to change vcpu_is_preempted() argument type to long to ease the writing of the assembly code. v1->v2: - Rerun the fio test on a different system on both bare-metal and a KVM guest. Both sockets were

v3->v4: - Fix x86-32 build error. v2->v3: - Provide an optimized __raw_callee_save___kvm_vcpu_is_preempted() in assembly as suggested by PeterZ. - Add a new patch to change vcpu_is_preempted() argument type to long to ease the writing of the assembly code. v1->v2: - Rerun the fio test on a different system on both bare-metal and a KVM guest. Both sockets were

v2->v3: - Provide an optimized __raw_callee_save___kvm_vcpu_is_preempted() in assembly as suggested by PeterZ. - Add a new patch to change vcpu_is_preempted() argument type to long to ease the writing of the assembly code. v1->v2: - Rerun the fio test on a different system on both bare-metal and a KVM guest. Both sockets were utilized in this test. - The commit log was

v2->v3: - Provide an optimized __raw_callee_save___kvm_vcpu_is_preempted() in assembly as suggested by PeterZ. - Add a new patch to change vcpu_is_preempted() argument type to long to ease the writing of the assembly code. v1->v2: - Rerun the fio test on a different system on both bare-metal and a KVM guest. Both sockets were utilized in this test. - The commit log was

From: Zengruan Ye <yezengruan at huawei.com> This patch set aims to support the vcpu_is_preempted() functionality under KVM/arm64, which allowing the guest to obtain the vcpu is currently running or not. This will enhance lock performance on overcommitted hosts (more runnable vcpus than physical cpus in the system) as doing busy waits for preempted vcpus will hurt system performance far

From: Zengruan Ye <yezengruan at huawei.com> This patch set aims to support the vcpu_is_preempted() functionality under KVM/arm64, which allowing the guest to obtain the vcpu is currently running or not. This will enhance lock performance on overcommitted hosts (more runnable vcpus than physical cpus in the system) as doing busy waits for preempted vcpus will hurt system performance far

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

This patch set aims to support the vcpu_is_preempted() functionality under KVM/arm64, which allowing the guest to obtain the VCPU is currently running or not. This will enhance lock performance on overcommitted hosts (more runnable VCPUs than physical CPUs in the system) as doing busy waits for preempted VCPUs will hurt system performance far worse than early yielding. We have observed some

...MP) && defined(CONFIG_PARAVIRT_SPINLOCKS) @@ -694,6 +694,9 @@ static __always_inline bool pv_vcpu_is_preempted(long cpu) return PVOP_CALLEE1(bool, pv_lock_ops.vcpu_is_preempted, cpu); } +void __raw_callee_save___native_queued_spin_unlock(struct qspinlock *lock); +bool __raw_callee_save___native_vcpu_is_preempted(long cpu); + #endif /* SMP && PARAVIRT_SPINLOCKS */ #ifdef CONFIG_X86_32 @@ -862,7 +865,7 @@ extern void default_banner(void); COND_POP(set, CLBR_RCX, rcx); \ COND_POP(set, CLBR_RAX, rax) -#define PARA_PATCH(struct, off) ((PARAVIRT_PATCH_##struct + (off)) / 8) +#define PAR...

change from v6: fix typos and remove uncessary comments. change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: