Commit 98c94f10 authored by Wei Yang's avatar Wei Yang Committed by Andrew Morton
Browse files

mm/pageblock-flags: remove PB_migratetype_bits/PB_migrate_end 

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: default avatarWei Yang <richard.weiyang@gmail.com>
Suggested-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent dd3b304b

include/linux/pageblock-flags.h

+5 −7
Original line number Diff line number Diff line
@@ -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

mm/page_alloc.c

+2 −2
Original line number Diff line number Diff line
@@ -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);