Proposal to report GPU private memory allocations with sysfs nodes [plain text version]

[Jerome Glisse]

On Tue, Nov 12, 2019 at 10:17:10AM -0800, Yiwei Zhang wrote:
> Hi folks,
> 
> What do you think about:
> > For the sysfs approach, I'm assuming the upstream vendors still need
> > to provide a pair of UMD and KMD, and this ioctl to label the BO is
> > kept as driver private ioctl. Then will each driver just define their
> > own set of "label"s and the KMD will only consume the corresponding
> > ones so that the sysfs nodes won't change at all? Report zero if
> > there's no allocation or re-use under a particular "label".

To me this looks like a way to abuse the kernel into provide a specific
message passing API between process only for GPU. It would be better to
use existing kernel/userspace API to pass message between process than
add a new one just for a special case.

Note that I believe that listing GPU allocation for a process might
useful but only if it is a generic thing accross all GPU (for upstream
GPU driver we do not care about non upstream).

Cheers,
Jérôme