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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2023-03-15 14:31:33 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-04-05 19:42:46 -0700
commit23baf831a32c04f9a968812511540b1b3e648bf5 (patch)
treefcaca52cefbef2707710ce057f58fb1c955a0559 /include/linux/mmzone.h
parent61883d3c32418f16e35e030ca0cfd5d2de95a649 (diff)
downloadlinux-23baf831a32c04f9a968812511540b1b3e648bf5.tar.gz
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 'include/linux/mmzone.h')
-rw-r--r--include/linux/mmzone.h10
1 files changed, 5 insertions, 5 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index bf8786d45b31e..35b11cc210d96 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -26,11 +26,11 @@
/* Free memory management - zoned buddy allocator. */
#ifndef CONFIG_ARCH_FORCE_MAX_ORDER
-#define MAX_ORDER 11
+#define MAX_ORDER 10
#else
#define MAX_ORDER CONFIG_ARCH_FORCE_MAX_ORDER
#endif
-#define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
+#define MAX_ORDER_NR_PAGES (1 << MAX_ORDER)
/*
* PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
@@ -93,7 +93,7 @@ static inline bool migratetype_is_mergeable(int mt)
}
#define for_each_migratetype_order(order, type) \
- for (order = 0; order < MAX_ORDER; order++) \
+ for (order = 0; order <= MAX_ORDER; order++) \
for (type = 0; type < MIGRATE_TYPES; type++)
extern int page_group_by_mobility_disabled;
@@ -922,7 +922,7 @@ struct zone {
CACHELINE_PADDING(_pad1_);
/* free areas of different sizes */
- struct free_area free_area[MAX_ORDER];
+ struct free_area free_area[MAX_ORDER + 1];
/* zone flags, see below */
unsigned long flags;
@@ -1745,7 +1745,7 @@ static inline bool movable_only_nodes(nodemask_t *nodes)
#define SECTION_BLOCKFLAGS_BITS \
((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
-#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
+#if (MAX_ORDER + PAGE_SHIFT) > SECTION_SIZE_BITS
#error Allocator MAX_ORDER exceeds SECTION_SIZE
#endif