Re: [PATCH v4 0/4] arm64: drop pfn_valid_within() and simplify pfn_valid()
From: Mike Rapoport <hidden>
Date: 2021-05-12 07:34:23
Also in:
kvmarm, linux-mm, lkml
On Wed, May 12, 2021 at 09:00:02AM +0200, Ard Biesheuvel wrote:
On Tue, 11 May 2021 at 12:05, Mike Rapoport [off-list ref] wrote:quoted
From: Mike Rapoport <redacted> Hi, These patches aim to remove CONFIG_HOLES_IN_ZONE and essentially hardwire pfn_valid_within() to 1. The idea is to mark NOMAP pages as reserved in the memory map and restore the intended semantics of pfn_valid() to designate availability of struct page for a pfn. With this the core mm will be able to cope with the fact that it cannot use NOMAP pages and the holes created by NOMAP ranges within MAX_ORDER blocks will be treated correctly even without the need for pfn_valid_within. The patches are boot tested on qemu-system-aarch64.Did you use EFI boot when testing this? The memory map is much more fragmented in that case, so this would be a good data point.
Right, something like this: [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000040000000-0x00000000ffffbfff] [ 0.000000] node 0: [mem 0x00000000ffffc000-0x00000000ffffffff] [ 0.000000] node 0: [mem 0x0000000100000000-0x00000004386fffff] [ 0.000000] node 0: [mem 0x0000000438700000-0x000000043899ffff] [ 0.000000] node 0: [mem 0x00000004389a0000-0x00000004389bffff] [ 0.000000] node 0: [mem 0x00000004389c0000-0x0000000438b5ffff] [ 0.000000] node 0: [mem 0x0000000438b60000-0x000000043be3ffff] [ 0.000000] node 0: [mem 0x000000043be40000-0x000000043becffff] [ 0.000000] node 0: [mem 0x000000043bed0000-0x000000043bedffff] [ 0.000000] node 0: [mem 0x000000043bee0000-0x000000043bffffff] [ 0.000000] node 0: [mem 0x000000043c000000-0x000000043fffffff] This is a pity really, because I don't see a fundamental reason for those tiny holes all over the place. I know that EFI/ACPI mandates "IO style" memory access for those regions, but I fail to get why...
quoted
I beleive it would be best to route these via mmotm tree. v4: * rebase on v5.13-rc1 v3: Link: https://lore.kernel.org/lkml/20210422061902.21614-1-rppt@kernel.org (local) * Fix minor issues found by Anshuman * Freshen up the declaration of pfn_valid() to make it consistent with pfn_is_map_memory() * Add more Acked-by and Reviewed-by tags, thanks Anshuman and David v2: Link: https://lore.kernel.org/lkml/20210421065108.1987-1-rppt@kernel.org (local) * Add check for PFN overflow in pfn_is_map_memory() * Add Acked-by and Reviewed-by tags, thanks David. v1: Link: https://lore.kernel.org/lkml/20210420090925.7457-1-rppt@kernel.org (local) * Add comment about the semantics of pfn_valid() as Anshuman suggested * Extend comments about MEMBLOCK_NOMAP, per Anshuman * Use pfn_is_map_memory() name for the exported wrapper for memblock_is_map_memory(). It is still local to arch/arm64 in the end because of header dependency issues. rfc: Link: https://lore.kernel.org/lkml/20210407172607.8812-1-rppt@kernel.org (local) Mike Rapoport (4): include/linux/mmzone.h: add documentation for pfn_valid() memblock: update initialization of reserved pages arm64: decouple check whether pfn is in linear map from pfn_valid() arm64: drop pfn_valid_within() and simplify pfn_valid() arch/arm64/Kconfig | 3 --- arch/arm64/include/asm/memory.h | 2 +- arch/arm64/include/asm/page.h | 3 ++- arch/arm64/kvm/mmu.c | 2 +- arch/arm64/mm/init.c | 14 +++++++++++++- arch/arm64/mm/ioremap.c | 4 ++-- arch/arm64/mm/mmu.c | 2 +- include/linux/memblock.h | 4 +++- include/linux/mmzone.h | 11 +++++++++++ mm/memblock.c | 28 ++++++++++++++++++++++++++-- 10 files changed, 60 insertions(+), 13 deletions(-) base-commit: 6efb943b8616ec53a5e444193dccf1af9ad627b5 -- 2.28.0
-- Sincerely yours, Mike. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel