| Message ID | 20200508182240.68440-1-jcargill@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kvm: add halt-polling cpu usage stats | expand |
On 08/05/20 20:22, Jon Cargille wrote: > From: David Matlack <dmatlack@google.com> > > Two new stats for exposing halt-polling cpu usage: > halt_poll_success_ns > halt_poll_fail_ns > > Thus sum of these 2 stats is the total cpu time spent polling. "success" > means the VCPU polled until a virtual interrupt was delivered. "fail" > means the VCPU had to schedule out (either because the maximum poll time > was reached or it needed to yield the CPU). > > To avoid touching every arch's kvm_vcpu_stat struct, only update and > export halt-polling cpu usage stats if we're on x86. I fixed all the other architectures and queued it, thanks. Paolo > > Exporting cpu usage as a u64 and in nanoseconds means we will overflow at > ~500 years, which seems reasonably large. > > Signed-off-by: David Matlack <dmatlack@google.com> > Signed-off-by: Jon Cargille <jcargill@google.com> > Reviewed-by: Jim Mattson <jmattson@google.com> > > --- > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/x86.c | 2 ++ > virt/kvm/kvm_main.c | 20 +++++++++++++++++--- > 3 files changed, 21 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index a239a297be33..3287159ab15b 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -1032,6 +1032,8 @@ struct kvm_vcpu_stat { > u64 irq_injections; > u64 nmi_injections; > u64 req_event; > + u64 halt_poll_success_ns; > + u64 halt_poll_fail_ns; > }; > > struct x86_instruction_info; > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 8c0b77ac8dc6..9736d91ce877 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -217,6 +217,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { > VCPU_STAT("nmi_injections", nmi_injections), > VCPU_STAT("req_event", req_event), > VCPU_STAT("l1d_flush", l1d_flush), > + VCPU_STAT( "halt_poll_success_ns", halt_poll_success_ns), > + VCPU_STAT( "halt_poll_fail_ns", halt_poll_fail_ns), > VM_STAT("mmu_shadow_zapped", mmu_shadow_zapped), > VM_STAT("mmu_pte_write", mmu_pte_write), > VM_STAT("mmu_pte_updated", mmu_pte_updated), > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 33e1eee96f75..348b4a6bde53 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -2664,19 +2664,30 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu) > return ret; > } > > +static inline void > +update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited) > +{ > +#ifdef CONFIG_X86 > + if (waited) > + vcpu->stat.halt_poll_fail_ns += poll_ns; > + else > + vcpu->stat.halt_poll_success_ns += poll_ns; > +#endif > +} > + > /* > * The vCPU has executed a HLT instruction with in-kernel mode enabled. > */ > void kvm_vcpu_block(struct kvm_vcpu *vcpu) > { > - ktime_t start, cur; > + ktime_t start, cur, poll_end; > DECLARE_SWAITQUEUE(wait); > bool waited = false; > u64 block_ns; > > kvm_arch_vcpu_blocking(vcpu); > > - start = cur = ktime_get(); > + start = cur = poll_end = ktime_get(); > if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) { > ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); > > @@ -2692,7 +2703,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) > ++vcpu->stat.halt_poll_invalid; > goto out; > } > - cur = ktime_get(); > + poll_end = cur = ktime_get(); > } while (single_task_running() && ktime_before(cur, stop)); > } > > @@ -2712,6 +2723,9 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) > kvm_arch_vcpu_unblocking(vcpu); > block_ns = ktime_to_ns(cur) - ktime_to_ns(start); > > + update_halt_poll_stats( > + vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited); > + > if (!kvm_arch_no_poll(vcpu)) { > if (!vcpu_valid_wakeup(vcpu)) { > shrink_halt_poll_ns(vcpu); >
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a239a297be33..3287159ab15b 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1032,6 +1032,8 @@ struct kvm_vcpu_stat { u64 irq_injections; u64 nmi_injections; u64 req_event; + u64 halt_poll_success_ns; + u64 halt_poll_fail_ns; }; struct x86_instruction_info; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8c0b77ac8dc6..9736d91ce877 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -217,6 +217,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = { VCPU_STAT("nmi_injections", nmi_injections), VCPU_STAT("req_event", req_event), VCPU_STAT("l1d_flush", l1d_flush), + VCPU_STAT( "halt_poll_success_ns", halt_poll_success_ns), + VCPU_STAT( "halt_poll_fail_ns", halt_poll_fail_ns), VM_STAT("mmu_shadow_zapped", mmu_shadow_zapped), VM_STAT("mmu_pte_write", mmu_pte_write), VM_STAT("mmu_pte_updated", mmu_pte_updated), diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 33e1eee96f75..348b4a6bde53 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2664,19 +2664,30 @@ static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu) return ret; } +static inline void +update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited) +{ +#ifdef CONFIG_X86 + if (waited) + vcpu->stat.halt_poll_fail_ns += poll_ns; + else + vcpu->stat.halt_poll_success_ns += poll_ns; +#endif +} + /* * The vCPU has executed a HLT instruction with in-kernel mode enabled. */ void kvm_vcpu_block(struct kvm_vcpu *vcpu) { - ktime_t start, cur; + ktime_t start, cur, poll_end; DECLARE_SWAITQUEUE(wait); bool waited = false; u64 block_ns; kvm_arch_vcpu_blocking(vcpu); - start = cur = ktime_get(); + start = cur = poll_end = ktime_get(); if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) { ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); @@ -2692,7 +2703,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) ++vcpu->stat.halt_poll_invalid; goto out; } - cur = ktime_get(); + poll_end = cur = ktime_get(); } while (single_task_running() && ktime_before(cur, stop)); } @@ -2712,6 +2723,9 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) kvm_arch_vcpu_unblocking(vcpu); block_ns = ktime_to_ns(cur) - ktime_to_ns(start); + update_halt_poll_stats( + vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited); + if (!kvm_arch_no_poll(vcpu)) { if (!vcpu_valid_wakeup(vcpu)) { shrink_halt_poll_ns(vcpu);