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Subject[PATCH v2 05/43] KVM: Update halt-polling stats if and only if halt-polling was attempted
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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.

Reviewed-by: 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 5d4a90032277..6156719bcbbc 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3217,6 +3217,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
{
struct rcuwait *wait = kvm_arch_vcpu_get_wait(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;
@@ -3224,7 +3225,7 @@ 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;
@@ -3276,8 +3277,9 @@ 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)) {
--
2.33.0.882.g93a45727a2-goog
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