Re: [PATCH v2 0/7] Allocate memmap from hotadded memory (per device)

From: David Hildenbrand
Date: Mon Feb 22 2021 - 06:31:13 EST


On 22.02.21 12:15, Oscar Salvador wrote:
On Wed, Feb 17, 2021 at 11:18:59AM +0100, Oscar Salvador wrote:
On Tue, Feb 09, 2021 at 02:38:47PM +0100, Oscar Salvador wrote:
Hi,

here is v2.

Changes from v1 -> v2
- Addressed feedback from David
- Fence off the feature in case struct page size is not
multiple of PMD size or pageblock alignment cannot be guaranted
- Tested on x86_64 small and large memory_blocks
- Tested on arm64 4KB and 64KB page sizes (for some reason I cannot boot
my VM with 16KB page size).

Arm64 with 4KB page size behaves like x86_64 after [1], which made section
size smaller.
With 64KB, the feature gets fenced off due to pageblock alignment.

Changes from RFCv3 -> v1:
- Addressed feedback from David
- Re-order patches

Changes from v2 -> v3 (RFC):
- Re-order patches (Michal)
- Fold "mm,memory_hotplug: Introduce MHP_MEMMAP_ON_MEMORY" in patch#1
- Add kernel boot option to enable this feature (Michal)

Changes from v1 -> v2 (RFC):
- Addressed feedback provided by David
- Add a arch_support_memmap_on_memory to be called
from mhp_supports_memmap_on_memory, as atm,
only ARM, powerpc and x86_64 have altmat support.

[1] https://lore.kernel.org/lkml/cover.1611206601.git.sudaraja@xxxxxxxxxxxxxx/

Let me refloat this one :-)

Kindly ping :-)

-EBUSY, will try having a look this week!

--
Thanks,

David / dhildenb