From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: [PATCH v2 2/2] kvm: x86: Drop useless atomic test from timer function Date: Tue, 09 Jun 2009 15:37:03 +0200 Message-ID: <4A2E657F.8080908@siemens.com> References: <4A2E2B3B.5020408@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: kvm-devel , Marcelo Tosatti To: Avi Kivity Return-path: Received: from gecko.sbs.de ([194.138.37.40]:18517 "EHLO gecko.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751130AbZFINhT (ORCPT ); Tue, 9 Jun 2009 09:37:19 -0400 In-Reply-To: <4A2E2B3B.5020408@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: 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 --- 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 36054e9..8dd1a55 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))