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| author | Sean Christopherson <seanjc@google.com> | 2021-10-08 19:12:09 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-12-08 04:24:52 -0500 |
| commit | 109a98260b533722d1190dcfa18447dd39fee5ff (patch) | |
| tree | dc9abf706ab963d37bc436c2401670dd4842de41 /virt | |
| parent | c3858335c711569b82a234a560dc19247e8f3fcc (diff) | |
| download | linux-stable-109a98260b533722d1190dcfa18447dd39fee5ff.tar.gz linux-stable-109a98260b533722d1190dcfa18447dd39fee5ff.tar.bz2 linux-stable-109a98260b533722d1190dcfa18447dd39fee5ff.zip | |
KVM: Don't redo ktime_get() when calculating halt-polling stop/deadline
Calculate the halt-polling "stop" time using "start" instead of redoing
ktime_get(). In practice, the numbers involved are in the noise (e.g.,
in the happy case where hardware correctly predicts do_halt_poll and
there are no interrupts, "start" is probably only a few cycles old)
and either approach is perfectly ok. But it's more precise to count
any extra latency toward the halt-polling time.
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-17-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2630db6e8cb5..97bde32082d0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3343,7 +3343,7 @@ void kvm_vcpu_halt(struct kvm_vcpu *vcpu) start = cur = poll_end = ktime_get(); if (do_halt_poll) { - ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); + ktime_t stop = ktime_add_ns(start, vcpu->halt_poll_ns); do { /* |