arm64/mm: add fallback option to allocate virtually contiguous memory

Browse source

When section mappings are enabled, we allocate vmemmap pages from
physically continuous memory of size PMD_SIZE using
vmemmap_alloc_block_buf(). Section mappings are good to reduce TLB
pressure. But when system is highly fragmented and memory blocks are
being hot-added at runtime, its possible that such physically continuous
memory allocations can fail. Rather than failing the memory hot-add
procedure, add a fallback option to allocate vmemmap pages from
discontinuous pages using vmemmap_populate_basepages().

Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/d6c06f2ef39bbe6c715b2f6db76eb16155fdcee6.1602722808.git.sudaraja@codeaurora.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

...

This commit is contained in:

Sudarshan Rajagopalan 2020-10-14 17:51:23 -07:00 • committed by Catalin Marinas

parent 0edaee42eb

commit 9f84f39f55

1 changed files with 5 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

7

arch/arm64/mm/mmu.c

View file