PG_buddy, an abandoned flag, indicates page(s) is/are free and in buddy allocator. And when page(s) in buddy allocator, the _mapcount will equal PAGE_BUDDY_MAPCOUNT_VALUE. So, here, "_mapcount equals PAGE_BUDDY_MAPCOUNT_VALUE" instead of "PG_buddy is set".
Signed-off-by: Haifeng Li <omy...@gmail.com> --- include/linux/mm_types.h | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 704a626..49d9247 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -126,7 +126,8 @@ struct page { * if PagePrivate set; used for * swp_entry_t if PageSwapCache; * indicates order in the buddy - * system if PG_buddy is set. + * system if _mapcount equals + * PAGE_BUDDY_MAPCOUNT_VALUE. */ #if USE_SPLIT_PTLOCKS spinlock_t ptl; -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/