From patchwork Wed Aug 19 13:02:13 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 42653 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n7JDCrXA022716 for ; Wed, 19 Aug 2009 13:12:59 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752277AbZHSNJa (ORCPT ); Wed, 19 Aug 2009 09:09:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752702AbZHSNJ2 (ORCPT ); Wed, 19 Aug 2009 09:09:28 -0400 Received: from mx2.redhat.com ([66.187.237.31]:50559 "EHLO mx2.redhat.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751932AbZHSNCr (ORCPT ); Wed, 19 Aug 2009 09:02:47 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n7JD2nwY005947; Wed, 19 Aug 2009 09:02:49 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n7JD2lw6003233; Wed, 19 Aug 2009 09:02:47 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n7JD2jNA023076; Wed, 19 Aug 2009 09:02:46 -0400 Received: from localhost.localdomain (cleopatra.tlv.redhat.com [10.35.255.11]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id 78AF12500C5; Wed, 19 Aug 2009 16:02:44 +0300 (IDT) From: Avi Kivity To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org 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> In-Reply-To: <1250686963-8357-1-git-send-email-avi@redhat.com> References: <1250686963-8357-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.58 on 172.16.27.26 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: 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))