Hi, I'd like to discuss memory persistence across kexec. Currently there is ongoing work on Kexec HandOver (KHO) [1] that allows serialization and deserialization of kernel data as well as preserving arbitrary memory ranges across kexec. In addition, KHO keeps a physically contiguous memory regions that are guaranteed to not have any memory that KHO would preserve, but still can be used by the system. The kexeced kernel bootstraps itself using those regions and sets all handed over memory as in use. KHO users then can recover their state from the preserved data. This includes memory reservations, where the user can either discard or claim reservations. KHO can be used as the base layer for implementation of persistence-aware memory allocator and persistent in-memory filesystem. Aside from status update on KHO progress there are a few topics that I would like to discuss: * Is it feasible and desirable to enable KHO support in tmpfs and hugetlbfs? * Or is it better to implement yet another in-memory filesystem dedicated for persistence? * What is the best way to ensure that the memory we want to persist is not scattered all over the place? [1] https://lore.kernel.org/all/20240117144704.602-1-graf@xxxxxxxxxx/ -- Sincerely yours, Mike.
