From 04e8cff3809b99417df8768083b8d3cb8fbe4f87 Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan@kernel.org>
Date: Mon, 8 Oct 2012 16:33:48 -0700
Subject: [PATCH] --- yaml --- r: 332469 b: refs/heads/master c:
 e46a28790e594c0876d1a84270926abf75460f61 h: refs/heads/master i:   332467:
 b038238076c4b775f7b194aa1cd0ea91ab076432 v: v3

---
 [refs]                       | 2 +-
 trunk/include/linux/mmzone.h | 2 ++
 trunk/mm/compaction.c        | 8 ++++++--
 trunk/mm/internal.h          | 2 +-
 trunk/mm/page_alloc.c        | 2 +-
 trunk/mm/vmscan.c            | 4 ++--
 6 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index f8a484f2a89f..42196d6d0595 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7a71932d5676b7410ab64d149bad8bde6b0d8632
+refs/heads/master: e46a28790e594c0876d1a84270926abf75460f61
diff --git a/trunk/include/linux/mmzone.h b/trunk/include/linux/mmzone.h
index a5578871d033..50aaca81f63d 100644
--- a/trunk/include/linux/mmzone.h
+++ b/trunk/include/linux/mmzone.h
@@ -218,6 +218,8 @@ struct lruvec {
 #define ISOLATE_UNMAPPED	((__force isolate_mode_t)0x2)
 /* Isolate for asynchronous migration */
 #define ISOLATE_ASYNC_MIGRATE	((__force isolate_mode_t)0x4)
+/* Isolate unevictable pages */
+#define ISOLATE_UNEVICTABLE	((__force isolate_mode_t)0x8)
 
 /* LRU Isolation modes. */
 typedef unsigned __bitwise__ isolate_mode_t;
diff --git a/trunk/mm/compaction.c b/trunk/mm/compaction.c
index d8187f9cabbf..2c4ce17651d8 100644
--- a/trunk/mm/compaction.c
+++ b/trunk/mm/compaction.c
@@ -461,6 +461,7 @@ static bool too_many_isolated(struct zone *zone)
  * @cc:		Compaction control structure.
  * @low_pfn:	The first PFN of the range.
  * @end_pfn:	The one-past-the-last PFN of the range.
+ * @unevictable: true if it allows to isolate unevictable pages
  *
  * Isolate all pages that can be migrated from the range specified by
  * [low_pfn, end_pfn).  Returns zero if there is a fatal signal
@@ -476,7 +477,7 @@ static bool too_many_isolated(struct zone *zone)
  */
 unsigned long
 isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
-			   unsigned long low_pfn, unsigned long end_pfn)
+		unsigned long low_pfn, unsigned long end_pfn, bool unevictable)
 {
 	unsigned long last_pageblock_nr = 0, pageblock_nr;
 	unsigned long nr_scanned = 0, nr_isolated = 0;
@@ -602,6 +603,9 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
 		if (!cc->sync)
 			mode |= ISOLATE_ASYNC_MIGRATE;
 
+		if (unevictable)
+			mode |= ISOLATE_UNEVICTABLE;
+
 		lruvec = mem_cgroup_page_lruvec(page, zone);
 
 		/* Try isolate the page */
@@ -807,7 +811,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
 	}
 
 	/* Perform the isolation */
-	low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn);
+	low_pfn = isolate_migratepages_range(zone, cc, low_pfn, end_pfn, false);
 	if (!low_pfn || cc->contended)
 		return ISOLATE_ABORT;
 
diff --git a/trunk/mm/internal.h b/trunk/mm/internal.h
index 4dc93e2fe69e..f5f295fe11e1 100644
--- a/trunk/mm/internal.h
+++ b/trunk/mm/internal.h
@@ -138,7 +138,7 @@ isolate_freepages_range(struct compact_control *cc,
 			unsigned long start_pfn, unsigned long end_pfn);
 unsigned long
 isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
-			   unsigned long low_pfn, unsigned long end_pfn);
+	unsigned long low_pfn, unsigned long end_pfn, bool unevictable);
 
 #endif
 
diff --git a/trunk/mm/page_alloc.c b/trunk/mm/page_alloc.c
index 5485f0ef4ec3..fd86c47de86f 100644
--- a/trunk/mm/page_alloc.c
+++ b/trunk/mm/page_alloc.c
@@ -5690,7 +5690,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
 		if (list_empty(&cc->migratepages)) {
 			cc->nr_migratepages = 0;
 			pfn = isolate_migratepages_range(cc->zone, cc,
-							 pfn, end);
+							 pfn, end, true);
 			if (!pfn) {
 				ret = -EINTR;
 				break;
diff --git a/trunk/mm/vmscan.c b/trunk/mm/vmscan.c
index 8b627309dd44..2624edcfb420 100644
--- a/trunk/mm/vmscan.c
+++ b/trunk/mm/vmscan.c
@@ -1009,8 +1009,8 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode)
 	if (!PageLRU(page))
 		return ret;
 
-	/* Do not give back unevictable pages for compaction */
-	if (PageUnevictable(page))
+	/* Compaction should not handle unevictable pages but CMA can do so */
+	if (PageUnevictable(page) && !(mode & ISOLATE_UNEVICTABLE))
 		return ret;
 
 	ret = -EBUSY;