Re: [Qemu-devel] [PATCH qemu] RFC: memory/hmp: Print owners/parents in "info mtree"

[Paolo Bonzini]

On 16/04/2018 16:27, Igor Mammedov wrote:
> On Mon, 16 Apr 2018 15:30:39 +0200
> Paolo Bonzini <address@hidden> wrote:
> 
>> On 16/04/2018 15:20, Igor Mammedov wrote:
>>> Generally object doesn't need to know its own name,
>>> we use it only for debugging and nice error reporting so far.
>>> I'd rather have 'id' property at Object level so we won't have
>>> to fish out ID from parent /which we aren't supposed to do and
>>> which doesn't work in some cases/ when it's needed within
>>> object itself.  
>>
>> Having an 'id' at object level is also a mess, because that id is
>> invalid after unparent.
> I'd just consider 'id' as object name which is valid even if there
> is no parent (during whole object lifecycle).

What's the point of an object name if it cannot be unique?

Paolo

> That would allow for object to have a reachable name vs getting NULL
> when parent isn't set.
> Maybe Object::id is overkill, but we probably could use NamedObject
> where it's needed and avoid reverse engineering id from path.
>  
>> Since this is just for debugging use,
>> object_get_canonical_path_component is the right function.  We can just
>> make it return NULL if there is no parent.
>
> looking at current use it out-grew just debugging usecases
> and it's rather messy right now:
> 
> ram_backend_memory_alloc, throttle_group_obj_complete,
> xlnx_zynqmp_create_rpu, spapr_drc.c:realize, iothread_complete,
> memory_region_name

I agree, _but_ it's definitely okay for debugging usecases.

Paolo