Hey, Den 2025-08-19 kl. 18:22, skrev Thomas Hellström: > Hi, Maarten, > > On Tue, 2025-08-19 at 13:49 +0200, Maarten Lankhorst wrote: >> Add an option to pin memory through the science of cgroup accounting. >> A bo will be pinned for its entire lifetime, and this allows buffers >> that are pinned for dma-buf export without requiring the pinning to >> be >> done at the dma-buf layer for all devices. >> >> For now only implement VRAM pinning. Dave Airlie has a series to >> implement >> memcg accounting for the GPU but that is not ready yet. > > Previous discussions around this have favoured a UAPI where we pin a > gpu-vm range, with a pin at mapping time, or dma-buf pin time where > required, this allows for dynamic pinning and unpinning, and would > avoid having separate pinning interfaces for bos and userptr. > > In particular if we don't know at bo creation time which buffer objects > will be exported with a method requiring pinning, how would UMD deduce > what buffer objects to pin? > > Thanks, > Thomas > For discussion purposes, it seems compute preferred pinning at allocation > time, so I wanted to propose that solution since it's easiest to implement.
I will change it for the next version, but I'm very interested in feedback on the adjustments I made in cgroups. Those are the ones that will have the most impact, and changes how effective min/low is calculated when memory pinned is involved. Kind regards, ~Maarten
