[PATCH 02/14] KVM: Update halt-polling stats if and only if halt-polling was attempted
From: Sean Christopherson <seanjc@google.com>
Date: 2021-09-25 00:55:41
Also in:
kvm, kvmarm, linux-arm-kernel, lkml
Subsystem:
kernel virtual machine (kvm), the rest · Maintainers:
Paolo Bonzini, Linus Torvalds
Don't update halt-polling stats if halt-polling wasn't attempted. This is a nop as @poll_ns is guaranteed to be '0' (poll_end == start), but it will allow a future patch to move the histogram stats into the helper to resolve a discrepancy in what is considered a "successful" halt-poll. No functional change intended. Cc: David Matlack <dmatlack@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> --- virt/kvm/kvm_main.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 768a4cbb26a6..8b33f5045b4d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c@@ -3214,6 +3214,7 @@ update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited) void kvm_vcpu_block(struct kvm_vcpu *vcpu) { bool halt_poll_allowed = !kvm_arch_no_poll(vcpu); + bool do_halt_poll = halt_poll_allowed && vcpu->halt_poll_ns; ktime_t start, cur, poll_end; bool waited = false; u64 block_ns;
@@ -3221,7 +3222,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) kvm_arch_vcpu_blocking(vcpu); start = cur = poll_end = ktime_get(); - if (vcpu->halt_poll_ns && halt_poll_allowed) { + if (do_halt_poll) { ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); ++vcpu->stat.generic.halt_attempted_poll;
@@ -3273,8 +3274,9 @@ 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 (do_halt_poll) + update_halt_poll_stats( + vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited); if (halt_poll_allowed) { if (!vcpu_valid_wakeup(vcpu)) {
--
2.33.0.685.g46640cef36-goog