Re: [Qemu-devel] [PATCH] kvm: First step to push iothread lock out of inner run loop

[Avi Kivity]

On 06/28/2012 05:10 PM, Anthony Liguori wrote:
>>
>> 1.  read_lock(memmap_lock)
>> 2.  MemoryRegionSection mrs = lookup(addr)
>> 3.  qom_ref(mrs.mr->dev)
>> 4.  read_unlock(memmap_lock)
>>
>> 5.  mutex_lock(dev->lock)
>> 6.  dispatch(&mrs, addr, data, size)
>> 7.  mutex_unlock(dev->lock)
> 
> Just a detail, I don't think we should acquire a device specific lock in
> global code.  Rather, I think we should acquire the global lock before
> dispatch unless a MemoryRegion is marked as being unlocked.

I think I agree.  The mutex acquisition is moved inside dispatch (in
device-specific code).  A side effect is that device code must not call
memory_region_destroy() outside its constructor or destructor.

-- 
error compiling committee.c: too many arguments to function