Cycling some of the Nvidia/nouveau guys here too.
I think there is a benefit on trying to estandarize how fdinfo can be used to expose per engine and device memory utilization.
Another of the advantages of going the /proc/ way instead of the sysfs debugfs approach is that you inherit the access lists directly from the distribution and you don't need to start messing with ownership and group access. By default an user can monitor its
own processes as long as /proc is mounted.
I am not saying that fdinfo or the way we implemented is 100% the way to go, but I'd rather have a solution within the confines of proc first.
David
From: Nieto, David M <David.Nieto@amd.com>
Sent: Monday, May 17, 2021 11:02 AM
To: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>; Daniel Vetter <daniel@ffwll.ch>; Koenig, Christian <Christian.Koenig@amd.com>
Cc: Alex Deucher <alexdeucher@gmail.com>; Intel Graphics Development <Intel-gfx@lists.freedesktop.org>; Maling list - DRI developers <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH 0/7] Per client engine busyness
The format is simple:
<ringname><index>: <XXX.XX> %
we also have entries for the memory mapped:
mem <ttm pool> : <size> KiB
To be absolutely honest, I agree that there is an overhead, but It might not be as much as you fear.
From: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Sent: Monday, May 17, 2021 9:00 AM
To: Nieto, David M <David.Nieto@amd.com>; Daniel Vetter <daniel@ffwll.ch>; Koenig, Christian <Christian.Koenig@amd.com>
Cc: Alex Deucher <alexdeucher@gmail.com>; Intel Graphics Development <Intel-gfx@lists.freedesktop.org>; Maling list - DRI developers <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH 0/7] Per client engine busyness
On 17/05/2021 15:39, Nieto, David M wrote:
> [AMD Official Use Only]
>
>
> Maybe we could try to standardize how the different submission ring
> usage gets exposed in the fdinfo? We went the simple way of just
> adding name and index, but if someone has a suggestion on how else we
> could format them so there is commonality across vendors we could just
> amend those.
Could you paste an example of your format?
Standardized fdinfo sounds good to me in principle. But I would also
like people to look at the procfs proposal from Chris,
- link to which I have pasted elsewhere in the thread.
Only potential issue with fdinfo I see at the moment is a bit of an
extra cost in DRM client discovery (compared to my sysfs series and also
procfs RFC from Chris). It would require reading all processes (well
threads, then maybe aggregating threads into parent processes), all fd
symlinks, and doing a stat on them to figure out which ones are DRM devices.
Btw is DRM_MAJOR 226 consider uapi? I don't see it in uapi headers.
> I’d really like to have the process managers tools display GPU usage
> regardless of what vendor is installed.
Definitely.
Regards,
Tvrtko