mm: migration: allow migration to operate asynchronously and avoid synchronous compac...

[mv-sheeva.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 03a66a31bfcdb12c356f53b3f8ccc6820f670993..0fd486467b4b953f318510744dc2b87d71f7d021 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1812,7 +1812,8 @@ 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, unsigned long *did_some_progress)
+       int migratetype, unsigned long *did_some_progress,
+       bool sync_migration)
 {
        struct page *page;
        struct task_struct *tsk = current;
@@ -1822,7 +1823,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
 
        tsk->flags |= PF_MEMALLOC;
        *did_some_progress = try_to_compact_pages(zonelist, order, gfp_mask,
-                                                               nodemask);
+                                               nodemask, sync_migration);
        tsk->flags &= ~PF_MEMALLOC;
        if (*did_some_progress != COMPACT_SKIPPED) {
 
@@ -1859,7 +1860,8 @@ 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, unsigned long *did_some_progress)
+       int migratetype, unsigned long *did_some_progress,
+       bool sync_migration)
 {
        return NULL;
 }
@@ -2001,6 +2003,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
        unsigned long pages_reclaimed = 0;
        unsigned long did_some_progress;
        struct task_struct *p = current;
+       bool sync_migration = false;
 
        /*
         * In the slowpath, we sanity check order to avoid ever trying to
@@ -2063,14 +2066,19 @@ rebalance:
        if (test_thread_flag(TIF_MEMDIE) && !(gfp_mask & __GFP_NOFAIL))
                goto nopage;
 
-       /* Try direct compaction */
+       /*
+        * 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, &did_some_progress);
+                                       migratetype, &did_some_progress,
+                                       sync_migration);
        if (page)
                goto got_pg;
+       sync_migration = true;
 
        /* Try direct reclaim and then allocating */
        page = __alloc_pages_direct_reclaim(gfp_mask, order,
@@ -2134,7 +2142,8 @@ rebalance:
                                        zonelist, high_zoneidx,
                                        nodemask,
                                        alloc_flags, preferred_zone,
-                                       migratetype, &did_some_progress);
+                                       migratetype, &did_some_progress,
+                                       sync_migration);
                if (page)
                        goto got_pg;
        }