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| author | Jason Baron <jbaron@akamai.com> | 2021-01-15 06:27:56 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-04 13:27:30 +0300 |
| commit | b3646477d458fbe7694a15b9c78fbe2fa426b703 (patch) | |
| tree | 6b2c5379acb1a28e4ffce63fc589fc76c18fd678 /arch/x86/kvm/irq.c | |
| parent | 9af5471bdbb2a26a1a46cd834e9fda6db6a9670e (diff) | |
| download | linux-b3646477d458fbe7694a15b9c78fbe2fa426b703.tar.xz | |
KVM: x86: use static calls to reduce kvm_x86_ops overhead
Convert kvm_x86_ops to use static calls. Note that all kvm_x86_ops are
covered here except for 'pmu_ops and 'nested ops'.
Here are some numbers running cpuid in a loop of 1 million calls averaged
over 5 runs, measured in the vm (lower is better).
Intel Xeon 3000MHz:
|default |mitigations=off
-------------------------------------
vanilla |.671s |.486s
static call|.573s(-15%)|.458s(-6%)
AMD EPYC 2500MHz:
|default |mitigations=off
-------------------------------------
vanilla |.710s |.609s
static call|.664s(-6%) |.609s(0%)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jason Baron <jbaron@akamai.com>
Message-Id: <e057bf1b8a7ad15652df6eeba3f907ae758d3399.1610680941.git.jbaron@akamai.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/irq.c')
| -rw-r--r-- | arch/x86/kvm/irq.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c index 814698e5b152..a035cca82f8f 100644 --- a/arch/x86/kvm/irq.c +++ b/arch/x86/kvm/irq.c @@ -143,8 +143,7 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu) { __kvm_migrate_apic_timer(vcpu); __kvm_migrate_pit_timer(vcpu); - if (kvm_x86_ops.migrate_timers) - kvm_x86_ops.migrate_timers(vcpu); + static_call_cond(kvm_x86_migrate_timers)(vcpu); } bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) |