[v3 0/2] Add memory sysfs directory and attributes

[Matt Roper]

On Mon, Dec 11, 2023 at 05:57:09PM -0500, Rodrigo Vivi wrote:
> On Mon, Dec 11, 2023 at 02:41:12PM -0800, Matt Roper wrote:
> > On Thu, Dec 07, 2023 at 08:47:37PM +0530, Sujaritha Sundaresan wrote:
> > > Create another layer of sub directories to clean up memory/vram
> > > related sysfs path. Additionally, introduce the vram frequency sysfs 
> > > under a the new path.
> > 
> > What's the userspace consumer of this uAPI?  How will this wind up
> > getting used in a real-world software stack?  Isn't stuff like the
> > memory size already returned via the query interface?
> 
> Please notice that this is more for frequency management, nothing related
> to the UMD information that we expose in the ioctl queries.

Are you sure?  The first patch here is moving a
'physical_vram_size_bytes' entry.  I believe we can get each tile's VRAM
size from the memory regions reported by the query ioctl as well, which
makes me wonder why this is also in sysfs and who's using it.  It was
already in sysfs before and is just moving location now, but if it's not
needed we could probably just remove it?

The frequency stuff shows up in the second patch, and "this is meant for
the end user to tweak directly" is fine, but that should probably be
stated explicitly.


Matt

> 
> Like every other sysfs interface, it doesn't actually matter what wrapper
> ends up using it. In general they are for system administrators to tune
> the hardware, so we just need to ensure that it makes sense, it is clean
> and something we will be able to maintain long term without breaking
> compatibility.
> 
> > 
> > 
> > Matt
> > 
> > > 
> > > Sujaritha Sundaresan (2):
> > >   drm/xe: Add a new memory directory under tile
> > >   drm/xe: Add vram frequency sysfs attributes
> > > 
> > >  drivers/gpu/drm/xe/xe_pcode_api.h  |   8 +++
> > >  drivers/gpu/drm/xe/xe_tile_sysfs.c | 101 +++++++++++++++++++++++++++--
> > >  2 files changed, 104 insertions(+), 5 deletions(-)
> > > 
> > > -- 
> > > 2.25.1
> > > 
> > 
> > -- 
> > Matt Roper
> > Graphics Software Engineer
> > Linux GPU Platform Enablement
> > Intel Corporation

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation