korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-16 08:44:21 +08:00
Code Issues Packages Projects Releases Wiki Activity

KVM: x86/pmu: Rewrite reprogram_counters() to improve performance

Browse Source 
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>
This commit is contained in:
Like Xu 2023-02-14 13:07:48 +08:00 committed by Sean Christopherson
parent 8bca8c5ce4
commit 649bccd7fa
1 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
arch/x86/kvm/vmx/pmu_intel.c
View File

@ -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)