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authorWang Nan <wangnan0@huawei.com>2014-08-07 03:06:08 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-07 05:01:18 +0400
commit1a4dc5bc7cb5659a8004d105afeb0571126f8f56 (patch)
treed3b95ffec47f6e6155e8a95efdcbc26cc1255e12 /include/linux/mmzone.h
parentb69deb2b7e13f04da5c0684c7ce19e788736ab0d (diff)
downloadlinux-1a4dc5bc7cb5659a8004d105afeb0571126f8f56.tar.xz
mem-hotplug: improve zone_movable_is_highmem logic
In original code, zone_movable_is_highmem() assumes ZONE_MOVABLE not highmem if CONFIG_HAVE_MEMBLOCK_NODE_MAP is not set. In online_pages, it extracts pages from the previous zone before ZONE_MOVABLE. Which is logically inconsistent: If HAVE_MEMBLOCK_NODE_MAP is turned off but HIGHMEM is on, zone_movable_is_highmem() makes movable zone not highmem, but online_pages() extracts pages from ZONE_HIGHMEM. This inconsistency doesn't cause real problem currently, because all architectures support online_pages also have HAVE_MEMBLOCK_NODE_MAP. However, fixing it makes code clear, and also helps futher coding. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Zhang Zhen <zhangzhen@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Jiang Liu <liuj97@gmail.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
-rw-r--r--include/linux/mmzone.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6cbd1b6c3d20..559e659288fc 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -872,6 +872,8 @@ static inline int zone_movable_is_highmem(void)
{
#if defined(CONFIG_HIGHMEM) && defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
return movable_zone == ZONE_HIGHMEM;
+#elif defined(CONFIG_HIGHMEM)
+ return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM;
#else
return 0;
#endif