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mm/pageblock-flags: remove PB_migratetype_bits/PB_migrate_end

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enum pageblock_bits defines the meaning of pageblock bits.  Currently
PB_migratetype_bits says the lowest 3 bits represents migratetype and
PB_migrate_end/MIGRATETYPE_MASK's definition rely on it with magical
computation.

Remove the definition of PB_migratetype_bits/PB_migrate_end.  Use
PB_migrate_[0|1|2] to represent lowest bits for migratetype.  Then we can
simplify related definition.

Also, MIGRATETYPE_AND_ISO_MASK is MIGRATETYPE_MASK add isolation bit.  Use
MIGRATETYPE_MASK in the definition of MIGRATETYPE_AND_ISO_MASK looks
cleaner.

No functional change intended.

Link: https://lkml.kernel.org/r/20250827070105.16864-3-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Wei Yang
2025-08-27 07:01:05 +00:00
committed by Andrew Morton
parent dd3b304b94
commit 98c94f1035
2 changed files with 7 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
include/linux/pageblock-flags.h
View File

@@ -13,12 +13,11 @@
#include <linux/types.h>
#define PB_migratetype_bits 3
/* Bit indices that affect a whole block of pages */
enum pageblock_bits {
PB_migrate,
PB_migrate_end = PB_migrate + PB_migratetype_bits - 1,
/* 3 bits required for migrate types */
PB_migrate_0,
PB_migrate_1,
PB_migrate_2,
PB_compact_skip,/* If set the block is skipped by compaction */
#ifdef CONFIG_MEMORY_ISOLATION
@@ -37,11 +36,10 @@ enum pageblock_bits {
#define NR_PAGEBLOCK_BITS (roundup_pow_of_two(__NR_PAGEBLOCK_BITS))
#define MIGRATETYPE_MASK ((1UL << (PB_migrate_end + 1)) - 1)
#define MIGRATETYPE_MASK (BIT(PB_migrate_0)|BIT(PB_migrate_1)|BIT(PB_migrate_2))
#ifdef CONFIG_MEMORY_ISOLATION
#define MIGRATETYPE_AND_ISO_MASK \
(((1UL << (PB_migrate_end + 1)) - 1) | BIT(PB_migrate_isolate))
#define MIGRATETYPE_AND_ISO_MASK (MIGRATETYPE_MASK | BIT(PB_migrate_isolate))
#else
#define MIGRATETYPE_AND_ISO_MASK MIGRATETYPE_MASK
#endif

4
mm/page_alloc.c
View File

@@ -355,7 +355,7 @@ static inline int pfn_to_bitidx(const struct page *page, unsigned long pfn)
static __always_inline bool is_standalone_pb_bit(enum pageblock_bits pb_bit)
{
return pb_bit > PB_migrate_end && pb_bit < __NR_PAGEBLOCK_BITS;
return pb_bit >= PB_compact_skip && pb_bit < __NR_PAGEBLOCK_BITS;
}
static __always_inline void
@@ -370,7 +370,7 @@ get_pfnblock_bitmap_bitidx(const struct page *page, unsigned long pfn,
#else
BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
#endif
BUILD_BUG_ON(__MIGRATE_TYPE_END >= (1 << PB_migratetype_bits));
BUILD_BUG_ON(__MIGRATE_TYPE_END > MIGRATETYPE_MASK);
VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
bitmap = get_pageblock_bitmap(page, pfn);