Re: [PATCH 2/2] drm/i915/debugfs: hook up ttm_resource_manager_debug

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On Thu, 2021-08-26 at 11:16 +0200, Daniel Vetter wrote:
> On Thu, Aug 19, 2021 at 09:32:20AM +0200, Thomas Hellström wrote:
> > On Wed, 2021-08-18 at 15:58 +0100, Matthew Auld wrote:
> > > This should give a more complete view of the various bits of
> > > internal
> > > resource manager state, for device local-memory.
> > > 
> > > Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> > > Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/i915_debugfs.c | 12 +++++++++---
> > >  1 file changed, 9 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> > > b/drivers/gpu/drm/i915/i915_debugfs.c
> > > index eec0d349ea6a..109e6feed6be 100644
> > > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > > @@ -238,6 +238,7 @@ i915_debugfs_describe_obj(struct seq_file *m,
> > > struct drm_i915_gem_object *obj)
> > >  static int i915_gem_object_info(struct seq_file *m, void *data)
> > >  {
> > >         struct drm_i915_private *i915 = node_to_i915(m->private);
> > > +       struct drm_printer p = drm_seq_file_printer(m);
> > >         struct intel_memory_region *mr;
> > >         enum intel_region_id id;
> > >  
> > > @@ -245,9 +246,14 @@ static int i915_gem_object_info(struct
> > > seq_file
> > > *m, void *data)
> > >                    i915->mm.shrink_count,
> > >                    atomic_read(&i915->mm.free_count),
> > >                    i915->mm.shrink_memory);
> > > -       for_each_memory_region(mr, i915, id)
> > > -               seq_printf(m, "%s: total:%pa, available:%pa
> > > bytes\n",
> > > -                          mr->name, &mr->total, &mr->avail);
> > > +       for_each_memory_region(mr, i915, id) {
> > > +               seq_printf(m, "%s: ", mr->name);
> > > +               if (mr->region_private)
> > > +                       ttm_resource_manager_debug(mr-
> > > > region_private, &p);
> > > +               else
> > > +                       seq_printf(m, "total:%pa, available:%pa
> > > bytes\n",
> > > +                                  &mr->total, &mr->avail);
> > 
> > Hm. Shouldn't we make the above intel_memory_region_debug() or
> > perhaps
> > intel_memory_region_info() to avoid using memory region internals
> > directly here?
> 
> Imo we should just emebed ttm_resource_mager into our own and not try
> to
> abstract this all away that much. At least in upstream there is just
> not
> going to be another memory region implementation, and for backporting
> I'm
> not sure these abstractions really help that much - we're touching
> all the
> same code still in the end.

Hmm, yes. Here I was seeing the separation between the debugfs code and
the intel_memory_region code, rather between the latter and TTM.

The i915 driver is currently much "everything uses everything" which
IMHO is not really good for code understanding and maintainance.

/Thomas

> -Daniel