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

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 16 Apr 2018 15:30:39 +0200
Paolo Bonzini <pbonzini@redhat.com> 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).
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


> Paolo