mm: compaction: fix bit ranges in {get,clear,set}_pageblock_skip()

bzolnier · torvalds · commit 627260595ca6 · 2012-10-11T08:50:14.000+09:00
{get,clear,set}_pageblock_skip() use incorrect bit ranges (please compare
to bit ranges used by {get,set}_pageblock_flags() used for migration
types) and can overwrite pageblock migratetype of the next pageblock in
the bitmap.

Signed-off-by: Bartlomiej Zolnierkiewicz &lt;b.zolnierkie@samsung.com&gt;
Signed-off-by: Kyungmin Park &lt;kyungmin.park@samsung.com&gt;
Acked-by: Mel Gorman &lt;mgorman@suse.de&gt;
Tested-by: Thierry Reding &lt;thierry.reding@avionic-design.de&gt;
Acked-by: Minchan Kim &lt;minchan@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h
@@ -71,13 +71,13 @@ void set_pageblock_flags_group(struct page *page, unsigned long flags,
 #ifdef CONFIG_COMPACTION
 #define get_pageblock_skip(page) \
 			get_pageblock_flags_group(page, PB_migrate_skip,     \
-							PB_migrate_skip + 1)
+							PB_migrate_skip)
 #define clear_pageblock_skip(page) \
 			set_pageblock_flags_group(page, 0, PB_migrate_skip,  \
-							PB_migrate_skip + 1)
+							PB_migrate_skip)
 #define set_pageblock_skip(page) \
 			set_pageblock_flags_group(page, 1, PB_migrate_skip,  \
-							PB_migrate_skip + 1)
+							PB_migrate_skip)
 #endif /* CONFIG_COMPACTION */
 
 #define get_pageblock_flags(page) \
