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authorPingfan Liu <kernelfans@gmail.com>2018-12-28 00:38:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 12:11:51 -0800
commit125b860b251ad226b1384b6db06be37485127f69 (patch)
tree412bd27ba3e790e00007e53a2a8cc31f88a82f2b /mm
parentfcf9a0ef8dc3a3fb8be9de12b0e006c85ed5dc29 (diff)
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mm/pageblock: throw compile error if pageblock_bits cannot hold MIGRATE_TYPES
Currently, NR_PAGEBLOCK_BITS and MIGRATE_TYPES are not associated by code. If someone adds extra migrate type, then he may forget to enlarge the NR_PAGEBLOCK_BITS. Hence it requires some way to fix. NR_PAGEBLOCK_BITS depends on MIGRATE_TYPES, while these macro spread on two different .h file with reverse dependency, it is a little hard to refer to MIGRATE_TYPES in pageblock-flag.h. This patch tries to remind such relation in compiling-time. Link: http://lkml.kernel.org/r/1544508709-11358-1-git-send-email-kernelfans@gmail.com Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_alloc.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b4fcf211ca69..cd1c9d32ef9a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -431,6 +431,7 @@ void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
unsigned long old_word, word;
BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
+ BUILD_BUG_ON(MIGRATE_TYPES > (1 << PB_migratetype_bits));
bitmap = get_pageblock_bitmap(page, pfn);
bitidx = pfn_to_bitidx(page, pfn);