diff options
| author | Wanpeng Li <wanpengli@tencent.com> | 2020-02-26 10:41:02 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-16 17:57:39 +0100 |
| commit | 4abaffce4d25aa41392d2e81835592726d757857 (patch) | |
| tree | 320b25cf896492063edcab40c3173e7a3e967bfb /arch/x86/include/asm | |
| parent | 49f933d445b611a237a4687ec7135b57b6b2cfba (diff) | |
KVM: LAPIC: Recalculate apic map in batch
In the vCPU reset and set APIC_BASE MSR path, the apic map will be recalculated
several times, each time it will consume 10+ us observed by ftrace in my
non-overcommit environment since the expensive memory allocate/mutex/rcu etc
operations. This patch optimizes it by recaluating apic map in batch, I hope
this can benefit the serverless scenario which can frequently create/destroy
VMs.
Before patch:
kvm_lapic_reset ~27us
After patch:
kvm_lapic_reset ~14us
Observed by ftrace, improve ~48%.
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 681e23071847..642273712e6a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -920,6 +920,7 @@ struct kvm_arch { atomic_t vapics_in_nmi_mode; struct mutex apic_map_lock; struct kvm_apic_map *apic_map; + bool apic_map_dirty; bool apic_access_page_done; unsigned long apicv_inhibit_reasons; |