This series adds a mechanism allowing platforms to weigh in and prevalidate incoming address range before proceeding further with the memory hotplug. This helps prevent potential platform errors for the given address range, down the hotplug call chain, which inevitably fails the hotplug itself.
This mechanism was suggested by David Hildenbrand during another discussion with respect to a memory hotplug fix on arm64 platform. https://lore.kernel.org/linux-arm-kernel/[email protected]/ This mechanism focuses on the addressibility aspect and not [sub] section alignment aspect. Hence check_hotplug_memory_range() and check_pfn_span() have been left unchanged. Wondering if all these can still be unified in an expanded memhp_range_allowed() check, that can be called from multiple memory hot add and remove paths. This series applies on v5.10-rc5 and has been slightly tested on arm64. But looking for some early feedback here. Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Mark Rutland <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Andrew Morton <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Anshuman Khandual (3): mm/hotplug: Pre-validate the address range with platform arm64/mm: Define arch_get_addressable_range() s390/mm: Define arch_get_addressable_range() arch/arm64/include/asm/memory.h | 3 ++ arch/arm64/mm/mmu.c | 19 ++++++------ arch/s390/include/asm/mmu.h | 2 ++ arch/s390/mm/vmem.c | 16 ++++++++--- include/linux/memory_hotplug.h | 51 +++++++++++++++++++++++++++++++++ mm/memory_hotplug.c | 29 ++++++------------- mm/memremap.c | 9 +++++- 7 files changed, 96 insertions(+), 33 deletions(-) -- 2.20.1
