diff mbox

[06/10] Move irq routing to its own locking.

Message ID 1249821671-32356-7-git-send-email-gleb@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Gleb Natapov Aug. 9, 2009, 12:41 p.m. UTC
Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
 include/linux/kvm_host.h |    1 +
 virt/kvm/irq_comm.c      |    4 ++--
 virt/kvm/kvm_main.c      |    1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

Comments

Avi Kivity Aug. 9, 2009, 2:52 p.m. UTC | #1
On 08/09/2009 03:41 PM, Gleb Natapov wrote:
> Signed-off-by: Gleb Natapov<gleb@redhat.com>
> ---
>   include/linux/kvm_host.h |    1 +
>   virt/kvm/irq_comm.c      |    4 ++--
>   virt/kvm/kvm_main.c      |    1 +
>   3 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index d573652..ce28cb7 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -175,6 +175,7 @@ struct kvm {
>   	struct mutex irq_lock;
>   #ifdef CONFIG_HAVE_KVM_IRQCHIP
>   	struct kvm_irq_routing_table *irq_routing;
> +	spinlock_t irq_routing_lock;
>    

Why is this needed?  The irq routing table adds very little contention 
since it is rcu locked.
diff mbox

Patch

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d573652..ce28cb7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -175,6 +175,7 @@  struct kvm {
 	struct mutex irq_lock;
 #ifdef CONFIG_HAVE_KVM_IRQCHIP
 	struct kvm_irq_routing_table *irq_routing;
+	spinlock_t irq_routing_lock;
 	struct hlist_head mask_notifier_list;
 	struct hlist_head irq_ack_notifier_list;
 #endif
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 6b09053..55eb6f6 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -368,10 +368,10 @@  int kvm_set_irq_routing(struct kvm *kvm,
 		++ue;
 	}
 
-	mutex_lock(&kvm->irq_lock);
+	spin_lock(&kvm->irq_routing_lock);
 	old = kvm->irq_routing;
 	rcu_assign_pointer(kvm->irq_routing, new);
-	mutex_unlock(&kvm->irq_lock);
+	spin_unlock(&kvm->irq_routing_lock);
 	synchronize_rcu();
 
 	new = old;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fcc0c44..2f4a47e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -944,6 +944,7 @@  static struct kvm *kvm_create_vm(void)
 	if (IS_ERR(kvm))
 		goto out;
 #ifdef CONFIG_HAVE_KVM_IRQCHIP
+	spin_lock_init(&kvm->irq_routing_lock);
 	INIT_HLIST_HEAD(&kvm->mask_notifier_list);
 	INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
 #endif