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. Signed-off-by: Wei Yang Cc: Zi Yan Cc: Vlastimil Babka Cc: David Hildenbrand Suggested-by: David Hildenbrand --- v2: remove PB_migratetype_bits and PB_migrate_end --- include/linux/pageblock-flags.h | 12 +++++------- mm/page_alloc.c | 4 ++-- 2 files changed, 7 insertions(+), 9 deletions(-) diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h index 6a44be0f39f4..6e4c2da15706 100644 --- a/include/linux/pageblock-flags.h +++ b/include/linux/pageblock-flags.h @@ -13,12 +13,11 @@ #include -#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 (PB_migrate_0|PB_migrate_1|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 diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e534f31a6b39..c1a18aaf8b41 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -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); -- 2.34.1