Revert "mm: compaction: handle incorrect MIGRATE_UNMOVABLE type pageblocks"

This reverts commit 5ceb9ce6fe9462a298bb2cd5c9f1ca6cb80a0199.

That commit seems to be the cause of the mm compation list corruption
issues that Dave Jones reported.  The locking (or rather, absense
there-of) is dubious, as is the use of the 'page' variable once it has
been found to be outside the pageblock range.

So revert it for now, we can re-visit this for 3.6.  If we even need to:
as Minchan Kim says, "The patch wasn't a bug fix and even test workload
was very theoretical".

Reported-and-tested-by: Dave Jones <davej@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 19 deletions

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index e988037abd2a..51a90b7f2d60 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -1,8 +1,6 @@
 #ifndef _LINUX_COMPACTION_H
 #define _LINUX_COMPACTION_H
 
-#include <linux/node.h>
-
 /* Return values for compact_zone() and try_to_compact_pages() */
 /* compaction didn't start as it was not possible or direct reclaim was more suitable */
 #define COMPACT_SKIPPED         0
@@ -13,23 +11,6 @@
 /* The full zone was compacted */
 #define COMPACT_COMPLETE        3
 
-/*
- * compaction supports three modes
- *
- * COMPACT_ASYNC_MOVABLE uses asynchronous migration and only scans
- *    MIGRATE_MOVABLE pageblocks as migration sources and targets.
- * COMPACT_ASYNC_UNMOVABLE uses asynchronous migration and only scans
- *    MIGRATE_MOVABLE pageblocks as migration sources.
- *    MIGRATE_UNMOVABLE pageblocks are scanned as potential migration
- *    targets and convers them to MIGRATE_MOVABLE if possible
- * COMPACT_SYNC uses synchronous migration and scans all pageblocks
- */
-enum compact_mode {
-        COMPACT_ASYNC_MOVABLE,
-        COMPACT_ASYNC_UNMOVABLE,
-        COMPACT_SYNC,
-};
-
 #ifdef CONFIG_COMPACTION
 extern int sysctl_compact_memory;
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,