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>

5 files changed, 38 insertions, 7 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 73b64a38b984..4f4c8c26fa9d 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -57,7 +57,9 @@ enum {
          */
         MIGRATE_CMA,
 #endif
+#ifdef CONFIG_MEMORY_ISOLATION
         MIGRATE_ISOLATE,        /* can't allocate from here */
+#endif
         MIGRATE_TYPES
 };
 
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index a92061e08d48..3fff8e774067 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -1,6 +1,25 @@
 #ifndef __LINUX_PAGEISOLATION_H
 #define __LINUX_PAGEISOLATION_H
 
+#ifdef CONFIG_MEMORY_ISOLATION
+static inline bool is_migrate_isolate_page(struct page *page)
+{
+        return get_pageblock_migratetype(page) == MIGRATE_ISOLATE;
+}
+static inline bool is_migrate_isolate(int migratetype)
+{
+        return migratetype == MIGRATE_ISOLATE;
+}
+#else
+static inline bool is_migrate_isolate_page(struct page *page)
+{
+        return false;
+}
+static inline bool is_migrate_isolate(int migratetype)
+{
+        return false;
+}
+#endif
 
 bool has_unmovable_pages(struct zone *zone, struct page *page, int count,
                          bool skip_hwpoisoned_pages);
diff --git a/mm/compaction.c b/mm/compaction.c
index 5d5b0b259bc9..ef53f352b606 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 @@ static bool suitable_migration_target(struct page *page)
         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 */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 07fe78d01ffd..e3fb290194c0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -673,7 +673,7 @@ static void free_pcppages_bulk(struct zone *zone, int count,
                         /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */
                         __free_one_page(page, zone, 0, mt);
                         trace_mm_page_pcpu_drain(page, 0, mt);
-                        if (likely(get_pageblock_migratetype(page) != MIGRATE_ISOLATE)) {
+                        if (likely(!is_migrate_isolate_page(page))) {
                                 __mod_zone_page_state(zone, NR_FREE_PAGES, 1);
                                 if (is_migrate_cma(mt))
                                         __mod_zone_page_state(zone, NR_FREE_CMA_PAGES, 1);
@@ -691,7 +691,7 @@ static void free_one_page(struct zone *zone, struct page *page, int order,
         zone->pages_scanned = 0;
 
         __free_one_page(page, zone, order, migratetype);
-        if (unlikely(migratetype != MIGRATE_ISOLATE))
+        if (unlikely(!is_migrate_isolate(migratetype)))
                 __mod_zone_freepage_state(zone, 1 << order, migratetype);
         spin_unlock(&zone->lock);
 }
@@ -923,7 +923,9 @@ static int fallbacks[MIGRATE_TYPES][4] = {
         [MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE,   MIGRATE_RESERVE },
 #endif
         [MIGRATE_RESERVE]     = { MIGRATE_RESERVE }, /* Never used */
+#ifdef CONFIG_MEMORY_ISOLATION
         [MIGRATE_ISOLATE]     = { MIGRATE_RESERVE }, /* Never used */
+#endif
 };
 
 /*
@@ -1149,7 +1151,7 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
                         list_add_tail(&page->lru, list);
                 if (IS_ENABLED(CONFIG_CMA)) {
                         mt = get_pageblock_migratetype(page);
-                        if (!is_migrate_cma(mt) && mt != MIGRATE_ISOLATE)
+                        if (!is_migrate_cma(mt) && !is_migrate_isolate(mt))
                                 mt = migratetype;
                 }
                 set_freepage_migratetype(page, mt);
@@ -1333,7 +1335,7 @@ void free_hot_cold_page(struct page *page, int cold)
          * excessively into the page allocator
          */
         if (migratetype >= MIGRATE_PCPTYPES) {
-                if (unlikely(migratetype == MIGRATE_ISOLATE)) {
+                if (unlikely(is_migrate_isolate(migratetype))) {
                         free_one_page(zone, page, 0, migratetype);
                         goto out;
                 }
@@ -1407,7 +1409,7 @@ static int __isolate_free_page(struct page *page, unsigned int order)
         zone = page_zone(page);
         mt = get_pageblock_migratetype(page);
 
-        if (mt != MIGRATE_ISOLATE) {
+        if (!is_migrate_isolate(mt)) {
                 /* Obey watermarks as if the page was being allocated */
                 watermark = low_wmark_pages(zone) + (1 << order);
                 if (!zone_watermark_ok(zone, 0, watermark, 0, 0))
@@ -1426,7 +1428,7 @@ static int __isolate_free_page(struct page *page, unsigned int order)
                 struct page *endpage = page + (1 << order) - 1;
                 for (; page < endpage; page += pageblock_nr_pages) {
                         int mt = get_pageblock_migratetype(page);
-                        if (mt != MIGRATE_ISOLATE && !is_migrate_cma(mt))
+                        if (!is_migrate_isolate(mt) && !is_migrate_cma(mt))
                                 set_pageblock_migratetype(page,
                                                           MIGRATE_MOVABLE);
                 }
@@ -2904,7 +2906,9 @@ static void show_migration_types(unsigned char type)
 #ifdef CONFIG_CMA
                 [MIGRATE_CMA]           = 'C',
 #endif
+#ifdef CONFIG_MEMORY_ISOLATION
                 [MIGRATE_ISOLATE]       = 'I',
+#endif
         };
         char tmp[MIGRATE_TYPES + 1];
         char *p = tmp;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index e3475f5fd983..c9d1f68120cd 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -628,7 +628,9 @@ static char * const migratetype_names[MIGRATE_TYPES] = {
 #ifdef CONFIG_CMA
         "CMA",
 #endif
+#ifdef CONFIG_MEMORY_ISOLATION
         "Isolate",
+#endif
 };
 
 static void *frag_start(struct seq_file *m, loff_t *pos)