From: Avi Kivity Subject: [PATCH 17/47] KVM: Drop useless atomic test from timer function Date: Wed, 19 Aug 2009 16:02:13 +0300 Message-ID: <1250686963-8357-18-git-send-email-avi@redhat.com> References: <1250686963-8357-1-git-send-email-avi@redhat.com> Cc: linux-kernel@vger.kernel.org To: kvm@vger.kernel.org Return-path: In-Reply-To: <1250686963-8357-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org From: Jan Kiszka 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 Signed-off-by: Avi Kivity --- arch/x86/kvm/timer.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/timer.c b/arch/x86/kvm/timer.c index 1baed41..eea4043 100644 --- a/arch/x86/kvm/timer.c +++ b/arch/x86/kvm/timer.c @@ -15,9 +15,9 @@ 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); + set_bit(KVM_REQ_PENDING_TIMER, &vcpu->requests); } if (waitqueue_active(q)) -- 1.6.3.3