kvm,lapic: Justify use of swait_active()
A comment might serve future readers.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index aaf10b6..69c5612 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1324,6 +1324,10 @@ static void apic_timer_expired(struct kvm_lapic *apic)
atomic_inc(&apic->lapic_timer.pending);
kvm_set_pending_timer(vcpu);
+ /*
+ * For x86, the atomic_inc() is serialized, thus
+ * using swait_active() is safe.
+ */
if (swait_active(q))
swake_up(q);