[RFC 4/6] drm: Add simple fdinfo memory helpers

[Rob Clark]

On Wed, Apr 19, 2023 at 6:16 AM Tvrtko Ursulin
<tvrtko.ursulin at linux.intel.com> wrote:
>
>
> On 18/04/2023 18:18, Rob Clark wrote:
> > On Mon, Apr 17, 2023 at 8:56 AM Tvrtko Ursulin
> > <tvrtko.ursulin at linux.intel.com> wrote:
> >>
> >> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >>
> >> For drivers who only wish to show one memory region called 'system,
> >> and only account the GEM buffer object handles under it.
> >>
> >> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> >> ---
> >>   drivers/gpu/drm/drm_file.c | 45 ++++++++++++++++++++++++++++++++++++++
> >>   include/drm/drm_file.h     |  6 +++++
> >>   2 files changed, 51 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> >> index e202f79e816d..1e70669dddf7 100644
> >> --- a/drivers/gpu/drm/drm_file.c
> >> +++ b/drivers/gpu/drm/drm_file.c
> >> @@ -872,6 +872,51 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
> >>   }
> >>   EXPORT_SYMBOL(drm_send_event);
> >>
> >> +static void
> >> +add_obj(struct drm_gem_object *obj, struct drm_fdinfo_memory_stat *stats)
> >> +{
> >> +       u64 sz = obj->size;
> >> +
> >> +       stats[0].size += sz;
> >> +
> >> +       if (obj->handle_count > 1)
> >> +               stats[0].shared += sz;
> >> +
> >> +       if (!dma_resv_test_signaled(obj->resv, dma_resv_usage_rw(true)))
> >> +               stats[0].active += sz;
> >> +
> >> +       /* Not supported. */
> >> +       stats[0].resident = ~0ull;
> >> +       stats[0].purgeable = ~0ull;
> >
> > Hmm, this kinda makes the simple helper not very useful.  In my
> > version, you get something that is useful for all UMA drivers (which
> > all, IIRC, have some form of madv ioctl).  I was kinda imagining that
> > for ttm drivers, my print_memory_stats() would just become a helper
> > and that TTM (or "multi-region") drivers would have their own thing.
>
> Hm how? Your version also needed a driver specific vfunc:

Sure, but there is a possibility for a driver specific vfunc ;-)

And arguably we could move madv to drm_gem_object, along with get/put
pages tracking.. since all the UMA drivers pretty much do the same
thing.  So maybe the vfunc is a temporary thing.

Anyways, I could go back to my original version where it was a helper
called from the driver to print mem stats.  That way, TTM drivers
could do their own thing.

BR,
-R

> +static enum drm_gem_object_status msm_gem_status(struct drm_gem_object *obj)
> +{
> +       struct msm_gem_object *msm_obj = to_msm_bo(obj);
> +       enum drm_gem_object_status status = 0;
> +
> +       if (msm_obj->pages)
> +               status |= DRM_GEM_OBJECT_RESIDENT;
> +
> +       if (msm_obj->madv == MSM_MADV_DONTNEED)
> +               status |= DRM_GEM_OBJECT_PURGEABLE;
> +
> +       return status;
> +}
>
> Regards,
>
> Tvrtko
>
> >
> > BR,
> > -R
> >
> >> +}
> >> +
> >> +char **
> >> +drm_query_fdinfo_system_region(struct drm_device *dev, unsigned int *num)
> >> +{
> >> +       static char *region[] = {
> >> +               "system",
> >> +       };
> >> +
> >> +       *num = 1;
> >> +
> >> +       return region;
> >> +}
> >> +EXPORT_SYMBOL(drm_query_fdinfo_system_region);
> >> +
> >> +void
> >> +drm_query_fdinfo_system_memory(struct drm_file *file,
> >> +                              struct drm_fdinfo_memory_stat *stats)
> >> +{
> >> +       struct drm_gem_object *obj;
> >> +       int id;
> >> +
> >> +       spin_lock(&file->table_lock);
> >> +       idr_for_each_entry(&file->object_idr, obj, id)
> >> +               add_obj(obj, stats);
> >> +       spin_unlock(&file->table_lock);
> >> +}
> >> +EXPORT_SYMBOL(drm_query_fdinfo_system_memory);
> >> +
> >>   static void
> >>   print_stat(struct drm_printer *p, const char *stat, const char *region, u64 sz)
> >>   {
> >> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> >> index 00d48beeac5c..dd7c6fb2c975 100644
> >> --- a/include/drm/drm_file.h
> >> +++ b/include/drm/drm_file.h
> >> @@ -383,6 +383,12 @@ struct drm_fdinfo_memory_stat {
> >>          u64 active;
> >>   };
> >>
> >> +char **drm_query_fdinfo_system_region(struct drm_device *dev,
> >> +                                     unsigned int *num);
> >> +void drm_query_fdinfo_system_memory(struct drm_file *file,
> >> +                                   struct drm_fdinfo_memory_stat *stats);
> >> +
> >> +
> >>   /**
> >>    * drm_is_primary_client - is this an open file of the primary node
> >>    * @file_priv: DRM file
> >> --
> >> 2.37.2
> >>