Hi, Matthew On Tue, 2024-08-27 at 19:48 -0700, Matthew Brost wrote: > +/** > + * DOC: Overview > + * > + * GPU Shared Virtual Memory (GPU SVM) layer for the Direct > Rendering Manager (DRM) > + * > + * The GPU SVM layer is a component of the DRM framework designed to > manage shared > + * virtual memory between the CPU and GPU. It enables efficient data > exchange and > + * processing for GPU-accelerated applications by allowing memory > sharing and > + * synchronization between the CPU's and GPU's virtual address > spaces. > + * > + * Key GPU SVM Components: > + * - Notifiers: Notifiers: Used for tracking memory intervals and > notifying the > + * GPU of changes, notifiers are sized based on a GPU > SVM > + * initialization parameter, with a recommendation of > 512M or > + * larger. They maintain a Red-BlacK tree and a list of > ranges that > + * fall within the notifier interval. Notifiers are > tracked within > + * a GPU SVM Red-BlacK tree and list and are > dynamically inserted > + * or removed as ranges within the interval are created > or > + * destroyed. > + * - Ranges: Represent memory ranges mapped in a DRM device and > managed > + * by GPU SVM. They are sized based on an array of chunk > sizes, which > + * is a GPU SVM initialization parameter, and the CPU > address space. > + * Upon GPU fault, the largest aligned chunk that fits > within the > + * faulting CPU address space is chosen for the range > size. Ranges are > + * expected to be dynamically allocated on GPU fault and > removed on an > + * MMU notifier UNMAP event. As mentioned above, ranges > are tracked in > + * a notifier's Red-Black tree. > + * - Operations: Define the interface for driver-specific SVM > operations such as > + * allocation, page collection, migration, > invalidations, and VRAM > + * release. > + * Another question, since ranges, as I understand it, are per gpuvm and per cpu mm, whereas migration is per device and per cpu_mm, (whe might have multiple gpuvms mapping the same cpu_mm), I figure the gpu_svm is per gpuvm, but that makes migration currently inconsistent, right? /Thomas
