mm: change isolate mode from #define to bitwise type

Change ISOLATE_XXX macro with bitwise isolate_mode_t type.  Normally,
macro isn't recommended as it's type-unsafe and making debugging harder as
symbol cannot be passed throught to the debugger.

Quote from Johannes
" Hmm, it would probably be cleaner to fully convert the isolation mode
into independent flags.  INACTIVE, ACTIVE, BOTH is currently a
tri-state among flags, which is a bit ugly."

This patch moves isolate mode from swap.h to mmzone.h by memcontrol.h

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 24 insertions, 19 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index b2977a5d659a..47f717fa4233 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -349,7 +349,8 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone,
                 }
 
                 /* Try isolate the page */
-                if (__isolate_lru_page(page, ISOLATE_BOTH, 0) != 0)
+                if (__isolate_lru_page(page,
+                                ISOLATE_ACTIVE|ISOLATE_INACTIVE, 0) != 0)
                         continue;
 
                 VM_BUG_ON(PageTransCompound(page));
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3508777837c7..2d5755544afe 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1185,7 +1185,8 @@ mem_cgroup_get_reclaim_stat_from_page(struct page *page)
 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                                         struct list_head *dst,
                                         unsigned long *scanned, int order,
-                                        int mode, struct zone *z,
+                                        isolate_mode_t mode,
+                                        struct zone *z,
                                         struct mem_cgroup *mem_cont,
                                         int active, int file)
 {
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9fdfce7ba403..ec6dbcb976d1 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1012,23 +1012,27 @@ keep_lumpy:
  *
  * returns 0 on success, -ve errno on failure.
  */
-int __isolate_lru_page(struct page *page, int mode, int file)
+int __isolate_lru_page(struct page *page, isolate_mode_t mode, int file)
 {
+        bool all_lru_mode;
         int ret = -EINVAL;
 
         /* Only take pages on the LRU. */
         if (!PageLRU(page))
                 return ret;
 
+        all_lru_mode = (mode & (ISOLATE_ACTIVE|ISOLATE_INACTIVE)) ==
+                (ISOLATE_ACTIVE|ISOLATE_INACTIVE);
+
         /*
          * When checking the active state, we need to be sure we are
          * dealing with comparible boolean values.  Take the logical not
          * of each.
          */
-        if (mode != ISOLATE_BOTH && (!PageActive(page) != !mode))
+        if (!all_lru_mode && !PageActive(page) != !(mode & ISOLATE_ACTIVE))
                 return ret;
 
-        if (mode != ISOLATE_BOTH && page_is_file_cache(page) != file)
+        if (!all_lru_mode && !!page_is_file_cache(page) != file)
                 return ret;
 
         /*
@@ -1076,7 +1080,8 @@ int __isolate_lru_page(struct page *page, int mode, int file)
  */
 static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                 struct list_head *src, struct list_head *dst,
-                unsigned long *scanned, int order, int mode, int file)
+                unsigned long *scanned, int order, isolate_mode_t mode,
+                int file)
 {
         unsigned long nr_taken = 0;
         unsigned long nr_lumpy_taken = 0;
@@ -1201,8 +1206,8 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 static unsigned long isolate_pages_global(unsigned long nr,
                                         struct list_head *dst,
                                         unsigned long *scanned, int order,
-                                        int mode, struct zone *z,
-                                        int active, int file)
+                                        isolate_mode_t mode,
+                                        struct zone *z, int active, int file)
 {
         int lru = LRU_BASE;
         if (active)
@@ -1448,6 +1453,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
         unsigned long nr_taken;
         unsigned long nr_anon;
         unsigned long nr_file;
+        isolate_mode_t reclaim_mode = ISOLATE_INACTIVE;
 
         while (unlikely(too_many_isolated(zone, file, sc))) {
                 congestion_wait(BLK_RW_ASYNC, HZ/10);
@@ -1458,15 +1464,15 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
         }
 
         set_reclaim_mode(priority, sc, false);
+        if (sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM)
+                reclaim_mode |= ISOLATE_ACTIVE;
+
         lru_add_drain();
         spin_lock_irq(&zone->lru_lock);
 
         if (scanning_global_lru(sc)) {
-                nr_taken = isolate_pages_global(nr_to_scan,
-                        &page_list, &nr_scanned, sc->order,
-                        sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM ?
-                                        ISOLATE_BOTH : ISOLATE_INACTIVE,
-                        zone, 0, file);
+                nr_taken = isolate_pages_global(nr_to_scan, &page_list,
+                        &nr_scanned, sc->order, reclaim_mode, zone, 0, file);
                 zone->pages_scanned += nr_scanned;
                 if (current_is_kswapd())
                         __count_zone_vm_events(PGSCAN_KSWAPD, zone,
@@ -1475,12 +1481,9 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone,
                         __count_zone_vm_events(PGSCAN_DIRECT, zone,
                                                nr_scanned);
         } else {
-                nr_taken = mem_cgroup_isolate_pages(nr_to_scan,
-                        &page_list, &nr_scanned, sc->order,
-                        sc->reclaim_mode & RECLAIM_MODE_LUMPYRECLAIM ?
-                                        ISOLATE_BOTH : ISOLATE_INACTIVE,
-                        zone, sc->mem_cgroup,
-                        0, file);
+                nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list,
+                        &nr_scanned, sc->order, reclaim_mode, zone,
+                        sc->mem_cgroup, 0, file);
                 /*
                  * mem_cgroup_isolate_pages() keeps track of
                  * scanned pages on its own.