Re: [Qemu-devel] [PATCH 1/5] qom: adopt rwlock to protect accessing dev from removing it

[liu ping fan]

On Thu, Jul 26, 2012 at 9:00 PM, Avi Kivity <address@hidden> wrote:
> On 07/26/2012 03:56 PM, liu ping fan wrote:
>> On Wed, Jul 25, 2012 at 5:08 PM, Paolo Bonzini <address@hidden> wrote:
>>> Il 25/07/2012 05:31, Liu Ping Fan ha scritto:
>>>> From: Liu Ping Fan <address@hidden>
>>>>
>>>> rwlock:
>>>>   qemu_device_tree_mutex
>>>>
>>>> rd side:
>>>>   --device_del(destruction of device will be postphoned until unplug
>>>>     ack from guest),
>>>>   --pci hot-unplug
>>>>   --iteration (qdev_reset_all)
>>>>
>>>> wr side:
>>>>   --device_add
>>>>
>>>
>>> This is not defined anywhere, is a piece missing in the patch?
>>>
>> Oh, yes, I miss the patch.  In that patch, these rwlock are just place 
>> holder.
>> I see there is already try to implement rwlock for qemu.
>>     http://lists.gnu.org/archive/html/qemu-devel/2011-10/msg00192.html
>> and is it the time for introduce rwlock for qemu?
>
>
> From the description above, I don't see why it can't be a mutex.
>
Searching in the device tree (or MemoryRegion view) can be often in
parallel, especially in mmio-dispatch code path

Thanx,  pingfan
> --
> error compiling committee.c: too many arguments to function
>
>