[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] lock in vhpet



On 18/04/2012 08:55, "Zhang, Yang Z" <yang.z.zhang@xxxxxxxxx> wrote:

>> If the HPET accesses are atomic on bare metal, we have to maintain that, even
>> if some guests have extra locking themselves. Also, in some cases Xen needs
>> locking to correctly maintain its own internal state regardless of what an
>> (untrusted) guest might do. So we cannot just get rid of the vhpet lock
>> everywhere. It's definitely not correct to do so. Optimising the hpet read
>> path
>> however, sounds okay. I agree the lock may not be needed on that specific
>> path.
> 
> You are right.
> For this case, since the main access of hpet is to read the main counter, so I
> think the rwlock is a better choice.

I'll see if I can make a patch...

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.