diff options
| author | Like Xu <likexu@tencent.com> | 2023-02-14 13:07:48 +0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-04-06 16:04:31 -0700 |
| commit | 649bccd7fac98225525c79cf4b1cecc4bafdfc54 (patch) | |
| tree | 0b4f2106e08187685229d0c731120768c73767c7 | |
| parent | 8bca8c5ce40b03862d782b9991da146909199327 (diff) | |
KVM: x86/pmu: Rewrite reprogram_counters() to improve performance
A valid pmc is always tested before using pmu->reprogram_pmi. Eliminate
this part of the redundancy by setting the counter's bitmask directly,
and in addition, trigger KVM_REQ_PMU only once to save more cpu cycles.
Signed-off-by: Like Xu <likexu@tencent.com>
Link: https://lore.kernel.org/r/20230214050757.9623-4-likexu@tencent.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/vmx/pmu_intel.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index c45bd10f80a1..eb291dfbe4aa 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -76,13 +76,13 @@ static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx) static void reprogram_counters(struct kvm_pmu *pmu, u64 diff) { int bit; - struct kvm_pmc *pmc; - for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX) { - pmc = intel_pmc_idx_to_pmc(pmu, bit); - if (pmc) - kvm_pmu_request_counter_reprogam(pmc); - } + if (!diff) + return; + + for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX) + set_bit(bit, pmu->reprogram_pmi); + kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu)); } static bool intel_hw_event_available(struct kvm_pmc *pmc) |