[PATCH 4/4] Convert irq notifiers lists to RCU locking.

Gleb Natapov
2009-07-12T12:03:56Z

Use RCU locking for mask/ack notifiers lists.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
virt/kvm/irq_comm.c | 20 +++++++++++---------
1 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 5dde1ef..ba3a115 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -179,18 +179,18 @@ void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
break;
}
}
- rcu_read_unlock();

- hlist_for_each_entry(kian, n, &kvm->irq_ack_notifier_list, link)
+ hlist_for_each_entry_rcu(kian, n, &kvm->irq_ack_notifier_list, link)
if (kian->gsi == gsi)
kian->irq_acked(kian);
+ rcu_read_unlock();
}

void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
mutex_lock(&kvm->irq_lock);
- hlist_add_head(&kian->link, &kvm->irq_ack_notifier_list);
+ hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
mutex_unlock(&kvm->irq_lock);
}

@@ -198,8 +198,9 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian)
{
mutex_lock(&kvm->irq_lock);
- hlist_del_init(&kian->link);
+ hlist_del_init_rcu(&kian->link);
mutex_unlock(&kvm->irq_lock);
+ synchronize_rcu();
}

int kvm_request_irq_source_id(struct kvm *kvm)
@@ -246,7 +247,7 @@ void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
{
mutex_lock(&kvm->irq_lock);
kimn->irq = irq;
- hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
+ hlist_add_head_rcu(&kimn->link, &kvm->mask_notifier_list);
mutex_unlock(&kvm->irq_lock);
}

@@ -254,8 +255,9 @@ void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
struct kvm_irq_mask_notifier *kimn)
{
mutex_lock(&kvm->irq_lock);
- hlist_del(&kimn->link);
+ hlist_del_rcu(&kimn->link);
mutex_unlock(&kvm->irq_lock);
+ synchronize_rcu();
}

void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
@@ -263,11 +265,11 @@ void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
struct kvm_irq_mask_notifier *kimn;
struct hlist_node *n;

- WARN_ON(!mutex_is_locked(&kvm->irq_lock));
-
- hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(kimn, n, &kvm->mask_notifier_list, link)
if (kimn->irq == irq)
kimn->func(kimn, mask);
+ rcu_read_unlock();
}

void kvm_free_irq_routing(struct kvm *kvm)
--
1.6.2.1