On Wed, May 17, 2023 at 02:56:13PM +0530, Sumit Garg wrote: > Do you mean a pinned user-space page can be paged out automatically? No, pinned pages can't be paged out. But a short term pin implies it will be release after a short delay, and it is feasible for wait for the pin to go away. For a long term pin waiting is not an option, and anyone wanting to do something with the pinned page that requires it to not be pinned must simply give up. > Just FYI, the underlying use-case for TEE registered shared memory is > that the references to pinned pages are provided to TEE implementation > to operate upon. This can happen over multiple syscalls and we want > the pinned pages to be always in RAM as otherwise the physical > addresses may change if they are paged out in between. That's a very use clear case for a long term pin.
