Commit 681405bf authored Jun 09, 2009 by Jan Kiszka Committed by Avi Kivity Sep 10, 2009

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>

parent f7104db2

arch/x86/kvm/timer.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -15,8 +15,8 @@ static int __kvm_timer_fn(struct kvm_vcpu vcpu, struct kvm_timer ktimer)
		* case anyway.
		*/
		if (ktimer->reinject \|\| !atomic_read(&ktimer->pending)) {
		atomic_inc(&ktimer->pending);
		/* FIXME: this code should not know anything about vcpus */
		if (!atomic_inc_and_test(&ktimer->pending))
		set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests);
		}