Re: [PATCH v2 0/2] drm: fdinfo memory stats

[Daniel Vetter]

On Tue, Apr 11, 2023 at 09:47:32AM -0700, Rob Clark wrote:
> On Mon, Apr 10, 2023 at 2:06 PM Rob Clark <robdclark@xxxxxxxxx> wrote:
> >
> > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> >
> > Similar motivation to other similar recent attempt[1].  But with an
> > attempt to have some shared code for this.  As well as documentation.
> >
> > It is probably a bit UMA-centric, I guess devices with VRAM might want
> > some placement stats as well.  But this seems like a reasonable start.
> >
> > Basic gputop support: https://patchwork.freedesktop.org/series/116236/
> > And already nvtop support: https://github.com/Syllo/nvtop/pull/204
> 
> On a related topic, I'm wondering if it would make sense to report
> some more global things (temp, freq, etc) via fdinfo?  Some of this,
> tools like nvtop could get by trawling sysfs or other driver specific
> ways.  But maybe it makes sense to have these sort of things reported
> in a standardized way (even though they aren't really per-drm_file)

I think that's a bit much layering violation, we'd essentially have to
reinvent the hwmon sysfs uapi in fdinfo. Not really a business I want to
be in :-)

What might be needed is better glue to go from the fd or fdinfo to the
right hw device and then crawl around the hwmon in sysfs automatically. I
would not be surprised at all if we really suck on this, probably more
likely on SoC than pci gpus where at least everything should be under the
main pci sysfs device.
-Daniel

> 
> BR,
> -R
> 
> 
> > [1] https://patchwork.freedesktop.org/series/112397/
> >
> > Rob Clark (2):
> >   drm: Add fdinfo memory stats
> >   drm/msm: Add memory stats to fdinfo
> >
> >  Documentation/gpu/drm-usage-stats.rst | 21 +++++++
> >  drivers/gpu/drm/drm_file.c            | 79 +++++++++++++++++++++++++++
> >  drivers/gpu/drm/msm/msm_drv.c         | 25 ++++++++-
> >  drivers/gpu/drm/msm/msm_gpu.c         |  2 -
> >  include/drm/drm_file.h                | 10 ++++
> >  5 files changed, 134 insertions(+), 3 deletions(-)
> >
> > --
> > 2.39.2
> >

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch