The patch titled
Subject: mm/page_alloc: fix the page address of higher page's buddy calculation
has been added to the -mm tree. Its filename is
mm-page_alloc-fix-the-page-address-of-higher-pages-buddy-calculation.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Li Haifeng <omycle@xxxxxxxxx>
Subject: mm/page_alloc: fix the page address of higher page's buddy calculation
The heuristic method for buddy has been introduced since 43506fad
("mm/page_alloc.c: simplify calculation of combined index of adjacent
buddy lists"). But the page address of higher page's buddy was wrongly
calculated, which will lead page_is_buddy to fail for ever. IOW, the
heuristic method would be disabled with the wrong page address of higher
page's buddy.
Calculating the page address of higher page's buddy should be based
higher_page with the offset between index of higher page and index of
higher page's buddy.
Signed-off-by: Haifeng Li <omycle@xxxxxxxxx>
Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Michal Hocko <mhocko@xxxxxxx>
Cc: KyongHo Cho <pullip.cho@xxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [2.6.38+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/page_alloc.c~mm-page_alloc-fix-the-page-address-of-higher-pages-buddy-calculation mm/page_alloc.c
--- a/mm/page_alloc.c~mm-page_alloc-fix-the-page-address-of-higher-pages-buddy-calculation
+++ a/mm/page_alloc.c
@@ -584,7 +584,7 @@ static inline void __free_one_page(struc
combined_idx = buddy_idx & page_idx;
higher_page = page + (combined_idx - page_idx);
buddy_idx = __find_buddy_index(combined_idx, order + 1);
- higher_buddy = page + (buddy_idx - combined_idx);
+ higher_buddy = higher_page + (buddy_idx - combined_idx);
if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
list_add_tail(&page->lru,
&zone->free_area[order].free_list[migratetype]);
_
Patches currently in -mm which might be from omycle@xxxxxxxxx are
mm-page_alloc-fix-the-page-address-of-higher-pages-buddy-calculation.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
