On 01.04.25 20:53, Oscar Salvador wrote:
On Mon, Jan 27, 2025 at 10:34:02AM -0500, Gregory Price wrote:
v8: nits and tag pickups
When physical address regions are not aligned to memory block size,
the misaligned portion is lost (stranded capacity).
Block size (min/max/selected) is architecture defined. Most architectures
tend to use the minimum block size or some simplistic heurist. On x86,
memory block size increases up to 2GB, and is otherwise fitted to the
alignment of non-hotplug (i.e. not special purpose memory).
I wonder if something like this could help us in improving the
ridiculous situation of having 16MB memory-block size on powerpc.
They have this granularity because ... they want to add/remove memory in
16MiB on some powerpc dlpar machines :(
probe_memory_block_size() can query the hypervisor on the actual
hot(un)plug size. IIRC, QEMU sets it to 256 MiB.
--
Cheers,
David / dhildenb
