CMA fixes for kernel 3.0

3 files changed, 37 insertions, 6 deletions

diff --git a/mm/ksm.c b/mm/ksm.c
index b126a7f..d623e5b 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1786,9 +1786,7 @@ void ksm_migrate_page(struct page *newpage, struct page *oldpage)
 		stable_node->kpfn = page_to_pfn(newpage);
 	}
 }
-#endif /* CONFIG_MIGRATION */
 
-#ifdef CONFIG_MEMORY_HOTREMOVE
 static struct stable_node *ksm_check_stable_tree(unsigned long start_pfn,
 						 unsigned long end_pfn)
 {
@@ -1805,6 +1803,27 @@ static struct stable_node *ksm_check_stable_tree(unsigned long start_pfn,
 	return NULL;
 }
 
+void ksm_start_migration(void)
+{
+	mutex_lock(&ksm_thread_mutex);
+}
+
+void ksm_finalize_migration(unsigned long start_pfn, unsigned long nr_pages)
+{
+	struct stable_node *stable_node;
+	while ((stable_node = ksm_check_stable_tree(start_pfn,
+				start_pfn + nr_pages)) != NULL)
+		remove_node_from_stable_tree(stable_node);
+	mutex_unlock(&ksm_thread_mutex);
+}
+
+void ksm_abort_migration(void)
+{
+	mutex_unlock(&ksm_thread_mutex);
+}
+#endif /* CONFIG_MIGRATION */
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
 static int ksm_memory_callback(struct notifier_block *self,
 			       unsigned long action, void *arg)
 {
diff --git a/mm/migrate.c b/mm/migrate.c
index 3e315a7..76abb9a 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -770,7 +770,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
 	 * File Caches may use write_page() or lock_page() in migration, then,
 	 * just care Anon page here.
 	 */
-	if (PageAnon(page)) {
+	if (PageAnon(page) && !PageKsm(page)) {
 		/*
 		 * Only page_lock_anon_vma() understands the subtleties of
 		 * getting a hold on an anon_vma from outside one of its mms.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fad3396..5a90077 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -58,6 +58,7 @@
 #include <linux/memcontrol.h>
 #include <linux/prefetch.h>
 #include <linux/migrate.h>
+#include <linux/ksm.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -5298,7 +5299,6 @@ static void __setup_per_zone_wmarks(void)
 			zone->watermark[WMARK_MIN] = min;
 		}
 
-
 		zone->watermark[WMARK_LOW]  = min_wmark_pages(zone) +
 					low + (min >> 2);
 		zone->watermark[WMARK_HIGH] = min_wmark_pages(zone) +
@@ -5898,7 +5898,7 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end)
 
 		ret = migrate_pages(&cc.migratepages,
 				    __alloc_contig_migrate_alloc,
-				    0, false, MIGRATE_SYNC);
+				    0, true, MIGRATE_SYNC);
 	}
 
 	putback_lru_pages(&cc.migratepages);
@@ -5943,7 +5943,7 @@ static int __reclaim_pages(struct zone *zone, gfp_t gfp_mask, int count)
 						      NULL);
 		if (!did_some_progress) {
 			/* Exhausted what can be done so it's blamo time */
-			out_of_memory(zonelist, gfp_mask, order, NULL, false);
+			out_of_memory(zonelist, gfp_mask, order, NULL);
 		}
 	}
 
@@ -5978,6 +5978,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 {
 	struct zone *zone = page_zone(pfn_to_page(start));
 	unsigned long outer_start, outer_end;
+        bool ksm_migration_started = false;
 	int ret = 0, order;
 
 	/*
@@ -6009,6 +6010,11 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 	if (ret)
 		goto done;
 
+	// Need to take KSM lock, so that we can specify offlining = true
+	// and move KSM pages.
+	ksm_start_migration();
+        ksm_migration_started = true;
+
 	ret = __alloc_contig_migrate_range(start, end);
 	if (ret)
 		goto done;
@@ -6070,9 +6076,15 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 	if (end != outer_end)
 		free_contig_range(end, outer_end - end);
 
+	// Finalize KSM migration.
+	ksm_finalize_migration(start, end - start);
+
 done:
 	undo_isolate_page_range(pfn_max_align_down(start),
 				pfn_max_align_up(end), migratetype);
+	if (ksm_migration_started) {
+		ksm_abort_migration();
+	}
 	return ret;
 }