Migration of peer-mapped memory pages

摘要

Techniques are provided by which memory pages may be migrated among PPU memories in a multi-PPU system. According to the techniques, a UVM driver determines that a particular memory page should change ownership state and/or be migrated between one PPU memory and another PPU memory. In response to this determination, the UVM driver initiates a peer transition sequence to cause the ownership state and/or location of the memory page to change. Various peer transition sequences involve modifying mappings for one or more PPU, and copying a memory page from one PPU memory to another PPU memory. Several steps in peer transition sequences may be performed in parallel for increased processing speed.

主权项

1. A computer-implemented method for modifying memory page ownership in a virtual memory subsystem having two or more parallel processing units (PPUs), the method comprising:
determining a current ownership state for a memory page that indicates which PPU in the virtual memory subsystem is associated with a PPU memory in which the memory page is currently stored and which additional PPUs in the virtual memory subsystem have page tables that include a page table entry with a mapping to the memory page; determining a new ownership state for the memory page that indicates which PPU in the virtual memory subsystem is associated with a PPU memory in which the memory page should be stored and which PPUs in the virtual memory subsystem should have page tables that include a page table entry corresponding to the memory page; and modifying a page table entry included in a page table associated with at least one PPU in the virtual memory subsystem, based on the current ownership state and the new ownership state.