From patchwork Wed Jan 12 07:41:22 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 473181 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p0C8XI2o022364 for ; Wed, 12 Jan 2011 08:33:45 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755756Ab1ALHlY (ORCPT ); Wed, 12 Jan 2011 02:41:24 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:65336 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754313Ab1ALHlW (ORCPT ); Wed, 12 Jan 2011 02:41:22 -0500 Received: from tang.cn.fujitsu.com (tang.cn.fujitsu.com [10.167.250.3]) by song.cn.fujitsu.com (Postfix) with ESMTP id 503C217003F; Wed, 12 Jan 2011 15:41:21 +0800 (CST) Received: from mailserver.fnst.cn.fujitus.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id p0C7a9dl000657; Wed, 12 Jan 2011 15:36:10 +0800 Received: from eric.localdomain ([10.167.225.99]) by mailserver.fnst.cn.fujitus.com (Lotus Domino Release 8.5.1FP4) with ESMTP id 2011011215405510-151511 ; Wed, 12 Jan 2011 15:40:55 +0800 Message-ID: <4D2D5B22.8070104@cn.fujitsu.com> Date: Wed, 12 Jan 2011 15:41:22 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM Subject: [PATCH v3 3/3] KVM: make make_all_cpus_request() lockless References: <4D2D5AA6.9080804@cn.fujitsu.com> In-Reply-To: <4D2D5AA6.9080804@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-01-12 15:40:55, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-01-12 15:40:56, Serialize complete at 2011-01-12 15:40:56 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Wed, 12 Jan 2011 08:33:45 +0000 (UTC) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index b99eacd..c8dee22 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -224,7 +224,6 @@ struct kvm_memslots { struct kvm { spinlock_t mmu_lock; - raw_spinlock_t requests_lock; struct mutex slots_lock; struct mm_struct *mm; /* userspace tied to this vm */ struct kvm_memslots *memslots; @@ -731,11 +730,6 @@ static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu) set_bit(req, &vcpu->requests); } -static inline bool kvm_make_check_request(int req, struct kvm_vcpu *vcpu) -{ - return test_and_set_bit(req, &vcpu->requests); -} - static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu) { if (test_bit(req, &vcpu->requests)) { diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 71a4eaf..c9eed53 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -147,11 +147,9 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req) zalloc_cpumask_var(&cpus, GFP_ATOMIC); - raw_spin_lock(&kvm->requests_lock); - me = smp_processor_id(); + me = get_cpu(); kvm_for_each_vcpu(i, vcpu, kvm) { - if (kvm_make_check_request(req, vcpu)) - continue; + kvm_make_request(req, vcpu); cpu = vcpu->cpu; /* Set ->requests bit before we read ->mode */ @@ -167,7 +165,7 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req) smp_call_function_many(cpus, ack_flush, NULL, 1); else called = false; - raw_spin_unlock(&kvm->requests_lock); + put_cpu(); free_cpumask_var(cpus); return called; } @@ -433,7 +431,6 @@ static struct kvm *kvm_create_vm(void) kvm->mm = current->mm; atomic_inc(&kvm->mm->mm_count); spin_lock_init(&kvm->mmu_lock); - raw_spin_lock_init(&kvm->requests_lock); kvm_eventfd_init(kvm); mutex_init(&kvm->lock); mutex_init(&kvm->irq_lock);