5 files changed, 12 insertions, 6 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index a5578871d03..50aaca81f63 100644
--- a/include/linux/mmzone.h
+++ b/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/mm/compaction.c b/mm/compaction.c
index d8187f9cabb..2c4ce17651d 100644
--- a/mm/compaction.c
+++ b/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/mm/internal.h b/mm/internal.h
index 4dc93e2fe69..f5f295fe11e 100644
--- a/mm/internal.h
+++ b/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/mm/page_alloc.c b/mm/page_alloc.c
index 5485f0ef4ec..fd86c47de86 100644
--- a/mm/page_alloc.c
+++ b/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/mm/vmscan.c b/mm/vmscan.c
index 8b627309dd4..2624edcfb42 100644
--- a/mm/vmscan.c
+++ b/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;