From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Mon, 23 Jun 2008 15:04:25 +0000 (-0300)
Subject: KVM: move slots_lock acquision down to vapic_exit
X-Git-Tag: v2.6.27-rc1~968^2~17
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f8b78fa3d406f3a2dc038e2b47749013a9295994;p=linux-2.6

KVM: move slots_lock acquision down to vapic_exit

There is no need to grab slots_lock if the vapic_page will not
be touched.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f726ba79fd..55906e4c46 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2787,8 +2787,10 @@ static void vapic_exit(struct kvm_vcpu *vcpu)
 	if (!apic || !apic->vapic_addr)
 		return;
 
+	down_read(&vcpu->kvm->slots_lock);
 	kvm_release_page_dirty(apic->vapic_page);
 	mark_page_dirty(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);
+	up_read(&vcpu->kvm->slots_lock);
 }
 
 static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
@@ -2944,9 +2946,7 @@ out:
 
 	post_kvm_run_save(vcpu, kvm_run);
 
-	down_read(&vcpu->kvm->slots_lock);
 	vapic_exit(vcpu);
-	up_read(&vcpu->kvm->slots_lock);
 
 	return r;
 }