Re: [PATCH] Move irq routing data structure to rcu locking

[Gleb Natapov <gleb@redhat.com>]

On Sun, Jul 12, 2009 at 12:50:05PM +0300, Avi Kivity wrote:
> On 07/09/2009 04:13 PM, Gleb Natapov wrote:
>> Change it from list to array to make RCU handling simpler.
>>
>> Signed-off-by: Gleb Natapov<gleb@redhat.com>
>> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
>> index f54a0d3..12d8d2b 100644
>> --- a/include/linux/kvm_host.h
>> +++ b/include/linux/kvm_host.h
>> @@ -161,7 +161,8 @@ struct kvm {
>>
>>   	struct mutex irq_lock;
>>   #ifdef CONFIG_HAVE_KVM_IRQCHIP
>> -	struct list_head irq_routing; /* of kvm_kernel_irq_routing_entry */
>> +	struct kvm_kernel_irq_routing_entry *irq_routing;
>> +	spinlock_t irq_routing_lock;
>>   	struct hlist_head mask_notifier_list;
>>   #endif
>>    
>
> Why the new lock?
>
Currently routing table is protected by irq_lock mutex, but irq_lock is
overused. It protects too much of unrelated things and it is not clear what
its real purpose in life. I want to rid of it completely.

--
			Gleb.