Re: [Qemu-devel] [patch v5 5/8] memory: introduce local lock for address space

[Avi Kivity <avi@redhat.com>]

On 10/29/2012 11:46 AM, liu ping fan wrote:
> On Mon, Oct 29, 2012 at 5:32 PM, Avi Kivity <avi@redhat.com> wrote:
>> On 10/29/2012 01:48 AM, Liu Ping Fan wrote:
>>> For those address spaces which want to be able out of big lock, they
>>> will be protected by their own local.
>>>
>>> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
>>> ---
>>>  memory.c |   11 ++++++++++-
>>>  memory.h |    5 ++++-
>>>  2 files changed, 14 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/memory.c b/memory.c
>>> index 2f68d67..ff34aed 100644
>>> --- a/memory.c
>>> +++ b/memory.c
>>> @@ -1532,9 +1532,15 @@ void memory_listener_unregister(MemoryListener *listener)
>>>      QTAILQ_REMOVE(&memory_listeners, listener, link);
>>>  }
>>>
>>> -void address_space_init(AddressSpace *as, MemoryRegion *root)
>>> +void address_space_init(AddressSpace *as, MemoryRegion *root, bool lock)
>>
>>
>> Why not always use the lock?  Even if the big lock is taken, it doesn't
>> hurt.  And eventually all address spaces will be fine-grained.
>>
> I had thought only mmio is out of big lock's protection. While others
> address space will take extra expense. So leave them until they are
> ready to be out of big lock.

The other address spaces are pio (which also needs fine-grained locking)
and the dma address spaces (which are like address_space_memory, except
they are accessed via DMA instead of from the vcpu).



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