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| author | Wanpeng Li <wanpengli@tencent.com> | 2020-02-28 11:18:41 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-16 17:57:40 +0100 |
| commit | b34de572a863b5a453dece431eac0da59b5aec0a (patch) | |
| tree | 1b6cc541608c178f2f3c9ca9ad1107c4cea3e288 /arch/x86/kvm/x86.c | |
| parent | 4abaffce4d25aa41392d2e81835592726d757857 (diff) | |
| download | lwn-b34de572a863b5a453dece431eac0da59b5aec0a.tar.gz lwn-b34de572a863b5a453dece431eac0da59b5aec0a.zip | |
KVM: X86: trigger kvmclock sync request just once on VM creation
In the progress of vCPUs creation, it queues a kvmclock sync worker to the global
workqueue before each vCPU creation completes. The workqueue subsystem guarantees
not to queue the already queued work; however, we can make the logic more clear by
making just one leader to trigger this kvmclock sync request, and also save on
cacheline bouncing caused by test_and_set_bit.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c5762c031b0c..78e34c968ab5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9335,11 +9335,9 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) mutex_unlock(&vcpu->mutex); - if (!kvmclock_periodic_sync) - return; - - schedule_delayed_work(&kvm->arch.kvmclock_sync_work, - KVMCLOCK_SYNC_PERIOD); + if (kvmclock_periodic_sync && vcpu->vcpu_idx == 0) + schedule_delayed_work(&kvm->arch.kvmclock_sync_work, + KVMCLOCK_SYNC_PERIOD); } void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) |