Browse Source

KVM: Drop useless atomic test from timer function

The current code tries to optimize the setting of
KVM_REQ_PENDING_TIMER but used atomic_inc_and_test - which always
returns true unless pending had the invalid value of -1 on entry. This
patch drops the test part preserving the original semantic but
expressing it less confusingly.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Jan Kiszka 16 years ago
parent
commit
681405bfc7
1 changed files with 2 additions and 2 deletions
  1. 2 2
      arch/x86/kvm/timer.c

+ 2 - 2
arch/x86/kvm/timer.c

@@ -15,9 +15,9 @@ static int __kvm_timer_fn(struct kvm_vcpu *vcpu, struct kvm_timer *ktimer)
 	 * case anyway.
 	 * case anyway.
 	 */
 	 */
 	if (ktimer->reinject || !atomic_read(&ktimer->pending)) {
 	if (ktimer->reinject || !atomic_read(&ktimer->pending)) {
+		atomic_inc(&ktimer->pending);
 		/* FIXME: this code should not know anything about vcpus */
 		/* FIXME: this code should not know anything about vcpus */
-		if (!atomic_inc_and_test(&ktimer->pending))
-			set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
+		set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
 	}
 	}
 
 
 	if (waitqueue_active(q))
 	if (waitqueue_active(q))