mm, compaction: embed migration mode in compact_control

We're going to want to manipulate the migration mode for compaction in the
page allocator, and currently compact_control's sync field is only a bool.

Currently, we only do MIGRATE_ASYNC or MIGRATE_SYNC_LIGHT compaction
depending on the value of this bool.  Convert the bool to enum
migrate_mode and pass the migration mode in directly.  Later, we'll want
to avoid MIGRATE_SYNC_LIGHT for thp allocations in the pagefault patch to
avoid unnecessary latency.

This also alters compaction triggered from sysfs, either for the entire
system or for a node, to force MIGRATE_SYNC.

[akpm@linux-foundation.org: fix build]
[iamjoonsoo.kim@lge.com: use MIGRATE_SYNC in alloc_contig_range()]
Signed-off-by: David Rientjes <rientjes@google.com>
Suggested-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 22 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 027d0294413a..afb29da0576c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2217,7 +2217,7 @@ static struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-        int migratetype, bool sync_migration,
+        int migratetype, enum migrate_mode mode,
         bool *contended_compaction, bool *deferred_compaction,
         unsigned long *did_some_progress)
 {
@@ -2231,7 +2231,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 
         current->flags |= PF_MEMALLOC;
         *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
-                                                nodemask, sync_migration,
+                                                nodemask, mode,
                                                 contended_compaction);
         current->flags &= ~PF_MEMALLOC;
 
@@ -2264,7 +2264,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
                  * As async compaction considers a subset of pageblocks, only
                  * defer if the failure was a sync compaction failure.
                  */
-                if (sync_migration)
+                if (mode != MIGRATE_ASYNC)
                         defer_compaction(preferred_zone, order);
 
                 cond_resched();
@@ -2277,9 +2277,8 @@ static inline struct page *
 __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
         struct zonelist *zonelist, enum zone_type high_zoneidx,
         nodemask_t *nodemask, int alloc_flags, struct zone *preferred_zone,
-        int migratetype, bool sync_migration,
-        bool *contended_compaction, bool *deferred_compaction,
-        unsigned long *did_some_progress)
+        int migratetype, enum migrate_mode mode, bool *contended_compaction,
+        bool *deferred_compaction, unsigned long *did_some_progress)
 {
         return NULL;
 }
@@ -2474,7 +2473,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
         int alloc_flags;
         unsigned long pages_reclaimed = 0;
         unsigned long did_some_progress;
-        bool sync_migration = false;
+        enum migrate_mode migration_mode = MIGRATE_ASYNC;
         bool deferred_compaction = false;
         bool contended_compaction = false;
 
@@ -2568,17 +2567,15 @@ rebalance:
          * Try direct compaction. The first pass is asynchronous. Subsequent
          * attempts after direct reclaim are synchronous
          */
-        page = __alloc_pages_direct_compact(gfp_mask, order,
-                                        zonelist, high_zoneidx,
-                                        nodemask,
-                                        alloc_flags, preferred_zone,
-                                        migratetype, sync_migration,
-                                        &contended_compaction,
+        page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
+                                        high_zoneidx, nodemask, alloc_flags,
+                                        preferred_zone, migratetype,
+                                        migration_mode, &contended_compaction,
                                         &deferred_compaction,
                                         &did_some_progress);
         if (page)
                 goto got_pg;
-        sync_migration = true;
+        migration_mode = MIGRATE_SYNC_LIGHT;
 
         /*
          * If compaction is deferred for high-order allocations, it is because
@@ -2653,12 +2650,10 @@ rebalance:
                  * direct reclaim and reclaim/compaction depends on compaction
                  * being called after reclaim so call directly if necessary
                  */
-                page = __alloc_pages_direct_compact(gfp_mask, order,
-                                        zonelist, high_zoneidx,
-                                        nodemask,
-                                        alloc_flags, preferred_zone,
-                                        migratetype, sync_migration,
-                                        &contended_compaction,
+                page = __alloc_pages_direct_compact(gfp_mask, order, zonelist,
+                                        high_zoneidx, nodemask, alloc_flags,
+                                        preferred_zone, migratetype,
+                                        migration_mode, &contended_compaction,
                                         &deferred_compaction,
                                         &did_some_progress);
                 if (page)
@@ -6218,7 +6213,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
                 cc->nr_migratepages -= nr_reclaimed;
 
                 ret = migrate_pages(&cc->migratepages, alloc_migrate_target,
-                                    NULL, 0, MIGRATE_SYNC, MR_CMA);
+                                    NULL, 0, cc->mode, MR_CMA);
         }
         if (ret < 0) {
                 putback_movable_pages(&cc->migratepages);
@@ -6257,7 +6252,7 @@ int alloc_contig_range(unsigned long start, unsigned long end,
                 .nr_migratepages = 0,
                 .order = -1,
                 .zone = page_zone(pfn_to_page(start)),
-                .sync = true,
+                .mode = MIGRATE_SYNC,
                 .ignore_skip_hint = true,
         };
         INIT_LIST_HEAD(&cc.migratepages);