The patch titled
Subject: arm64: reword ARCH_FORCE_MAX_ORDER prompt and help text
has been added to the -mm mm-unstable branch. Its filename is
arm64-reword-arch_force_max_order-prompt-and-help-text.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-reword-arch_force_max_order-prompt-and-help-text.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>
Subject: arm64: reword ARCH_FORCE_MAX_ORDER prompt and help text
Date: Fri, 24 Mar 2023 08:22:22 +0300
The prompt and help text of ARCH_FORCE_MAX_ORDER are not even close to
describe this configuration option.
Update both to actually describe what this option does.
Link: https://lkml.kernel.org/r/20230324052233.2654090-4-rppt@xxxxxxxxxx
Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Guo Ren <guoren@xxxxxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Rich Felker <dalias@xxxxxxxx>
Cc: "Russell King (Oracle)" <linux@xxxxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm64/Kconfig | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
--- a/arch/arm64/Kconfig~arm64-reword-arch_force_max_order-prompt-and-help-text
+++ a/arch/arm64/Kconfig
@@ -1487,24 +1487,24 @@ config XEN
# 16K | 27 | 14 | 13 | 11 |
# 64K | 29 | 16 | 13 | 13 |
config ARCH_FORCE_MAX_ORDER
- int "Maximum zone order" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES)
+ int "Order of maximal physically contiguous allocations" if ARM64_4K_PAGES || ARM64_16K_PAGES
default "13" if ARM64_64K_PAGES
default "11" if ARM64_16K_PAGES
default "10"
help
- The kernel memory allocator divides physically contiguous memory
- blocks into "zones", where each zone is a power of two number of
- pages. This option selects the largest power of two that the kernel
- keeps in the memory allocator. If you need to allocate very large
- blocks of physically contiguous memory, then you may need to
- increase this value.
+ The kernel page allocator limits the size of maximal physically
+ contiguous allocations. The limit is called MAX_ORDER and it
+ defines the maximal power of two of number of pages that can be
+ allocated as a single contiguous block. This option allows
+ overriding the default setting when ability to allocate very
+ large blocks of physically contiguous memory is required.
- We make sure that we can allocate up to a HugePage size for each configuration.
- Hence we have :
- MAX_ORDER = PMD_SHIFT - PAGE_SHIFT => PAGE_SHIFT - 3
+ The maximal size of allocation cannot exceed the size of the
+ section, so the value of MAX_ORDER should satisfy
- However for 4K, we choose a higher default value, 10 as opposed to 9, giving us
- 4M allocations matching the default size used by generic code.
+ MAX_ORDER + PAGE_SHIFT <= SECTION_SIZE_BITS
+
+ Don't change if unsure.
config UNMAP_KERNEL_AT_EL0
bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT
_
Patches currently in -mm which might be from rppt@xxxxxxxxxx are
loongarch-drop-ranges-for-definition-of-arch_force_max_order.patch
mips-drop-ranges-for-definition-of-arch_force_max_order.patch
mm-move-get_page_from_free_area-to-mm-page_allocc.patch
mips-fix-comment-about-pgtable_init.patch
mm-page_alloc-add-helper-for-checking-if-check_pages_enabled.patch
mm-move-most-of-core-mm-initialization-to-mm-mm_initc.patch
mm-handle-hashdist-initialization-in-mm-mm_initc.patch
mm-page_alloc-rename-page_alloc_init-to-page_alloc_init_cpuhp.patch
init-fold-build_all_zonelists-and-page_alloc_init_cpuhp-to-mm_init.patch
initmm-move-mm_init-to-mm-mm_initc-and-rename-it-to-mm_core_init.patch
mm-call-ptlockpgtable_cache_init-directly-from-mm_core_init.patch
mm-move-init_mem_debugging_and_hardening-to-mm-mm_initc.patch
initmm-fold-late-call-to-page_ext_init-to-page_alloc_init_late.patch
mm-move-mem_init_print_info-to-mm_initc.patch
mm-move-kmem_cache_init-declaration-to-mm-slabh.patch
mm-move-vmalloc_init-declaration-to-mm-internalh.patch
maintainers-extend-memblock-entry-to-include-mm-initialization.patch
arm-reword-arch_force_max_order-prompt-and-help-text.patch
arm64-drop-ranges-in-definition-of-arch_force_max_order.patch
arm64-reword-arch_force_max_order-prompt-and-help-text.patch
csky-drop-arch_force_max_order.patch
ia64-dont-allow-users-to-override-arch_force_max_order.patch
m68k-reword-arch_force_max_order-prompt-and-help-text.patch
nios2-reword-arch_force_max_order-prompt-and-help-text.patch
nios2-drop-ranges-for-definition-of-arch_force_max_order.patch
powerpc-reword-arch_force_max_order-prompt-and-help-text.patch
powerpc-drop-ranges-for-definition-of-arch_force_max_order.patch
sh-reword-arch_force_max_order-prompt-and-help-text.patch
sh-drop-ranges-for-definition-of-arch_force_max_order.patch
sparc-reword-arch_force_max_order-prompt-and-help-text.patch
xtensa-reword-arch_force_max_order-prompt-and-help-text.patch
