diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2023-03-15 12:31:33 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-06 04:42:46 +0200 |
| commit | 23baf831a32c04f9a968812511540b1b3e648bf5 (patch) | |
| tree | fcaca52cefbef2707710ce057f58fb1c955a0559 /arch/loongarch | |
| parent | iommu: fix MAX_ORDER usage in __iommu_dma_alloc_pages() (diff) | |
| download | linux-23baf831a32c04f9a968812511540b1b3e648bf5.tar.xz linux-23baf831a32c04f9a968812511540b1b3e648bf5.zip | |
mm, treewide: redefine MAX_ORDER sanely
MAX_ORDER currently defined as number of orders page allocator supports:
user can ask buddy allocator for page order between 0 and MAX_ORDER-1.
This definition is counter-intuitive and lead to number of bugs all over
the kernel.
Change the definition of MAX_ORDER to be inclusive: the range of orders
user can ask from buddy allocator is 0..MAX_ORDER now.
[kirill@shutemov.name: fix min() warning]
Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box
[akpm@linux-foundation.org: fix another min_t warning]
[kirill@shutemov.name: fixups per Zi Yan]
Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name
[akpm@linux-foundation.org: fix underlining in docs]
Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/
Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/loongarch')
| -rw-r--r-- | arch/loongarch/Kconfig | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 7fd51257e0ed..272a3a12c98d 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -420,12 +420,12 @@ config NODES_SHIFT config ARCH_FORCE_MAX_ORDER int "Maximum zone order" - range 14 64 if PAGE_SIZE_64KB - default "14" if PAGE_SIZE_64KB - range 12 64 if PAGE_SIZE_16KB - default "12" if PAGE_SIZE_16KB - range 11 64 - default "11" + range 13 63 if PAGE_SIZE_64KB + default "13" if PAGE_SIZE_64KB + range 11 63 if PAGE_SIZE_16KB + default "11" if PAGE_SIZE_16KB + range 10 63 + default "10" help The kernel memory allocator divides physically contiguous memory blocks into "zones", where each zone is a power of two number of @@ -434,9 +434,6 @@ config ARCH_FORCE_MAX_ORDER blocks of physically contiguous memory, then you may need to increase this value. - This config option is actually maximum order plus one. For example, - a value of 11 means that the largest free memory block is 2^10 pages. - The page size is not necessarily 4KB. Keep this in mind when choosing a value for this option. |