mm: remove MIGRATE_ISOLATE check in hotpath

Several functions test MIGRATE_ISOLATE and some of those are hotpath but
MIGRATE_ISOLATE is used only if we enable CONFIG_MEMORY_ISOLATION(ie,
CMA, memory-hotplug and memory-failure) which are not common config
option.  So let's not add unnecessary overhead and code when we don't
enable CONFIG_MEMORY_ISOLATION.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/compaction.c b/mm/compaction.c
index 5d5b0b2..ef53f35 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -15,6 +15,7 @@
 #include <linux/sysctl.h>
 #include <linux/sysfs.h>
 #include <linux/balloon_compaction.h>
+#include <linux/page-isolation.h>
 #include "internal.h"
 
 #ifdef CONFIG_COMPACTION
@@ -215,7 +216,10 @@
 	int migratetype = get_pageblock_migratetype(page);
 
 	/* Don't interfere with memory hot-remove or the min_free_kbytes blocks */
-	if (migratetype == MIGRATE_ISOLATE || migratetype == MIGRATE_RESERVE)
+	if (migratetype == MIGRATE_RESERVE)
+		return false;
+
+	if (is_migrate_isolate(migratetype))
 		return false;
 
 	/* If the page is a large free page, then allow migration */