mm/slab: make cache_grow() handle the page allocated on arbitrary node

Currently, cache_grow() assumes that allocated page's nodeid would be
same with parameter nodeid which is used for allocation request.  If we
discard this assumption, we can handle fallback_alloc() case gracefully.
So, this patch makes cache_grow() handle the page allocated on arbitrary
node and clean-up relevant code.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/slab.c b/mm/slab.c
index e181cfb..b303c04 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2556,13 +2556,14 @@ static void slab_map_pages(struct kmem_cache *cache, struct page *page,
  * Grow (by 1) the number of slabs within a cache.  This is called by
  * kmem_cache_alloc() when there are no active objs left in a cache.
  */
-static int cache_grow(struct kmem_cache *cachep,
-               gfp_t flags, int nodeid, struct page *page)
+static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 {
        void *freelist;
        size_t offset;
        gfp_t local_flags;
+       int page_node;
        struct kmem_cache_node *n;
+       struct page *page;
 
        /*
         * Be lazy and only check for valid flags here,  keeping it out of the
@@ -2590,12 +2591,12 @@ static int cache_grow(struct kmem_cache *cachep,
         * Get mem for the objs.  Attempt to allocate a physical page from
         * 'nodeid'.
         */
-       if (!page)
-               page = kmem_getpages(cachep, local_flags, nodeid);
+       page = kmem_getpages(cachep, local_flags, nodeid);
        if (!page)
                goto failed;
 
-       n = get_node(cachep, nodeid);
+       page_node = page_to_nid(page);
+       n = get_node(cachep, page_node);
 
        /* Get colour for the slab, and cal the next value. */
        n->colour_next++;
@@ -2610,7 +2611,7 @@ static int cache_grow(struct kmem_cache *cachep,
 
        /* Get slab management. */
        freelist = alloc_slabmgmt(cachep, page, offset,
-                       local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
+                       local_flags & ~GFP_CONSTRAINT_MASK, page_node);
        if (OFF_SLAB(cachep) && !freelist)
                goto opps1;
 
@@ -2629,13 +2630,13 @@ static int cache_grow(struct kmem_cache *cachep,
        STATS_INC_GROWN(cachep);
        n->free_objects += cachep->num;
        spin_unlock(&n->list_lock);
-       return 1;
+       return page_node;
 opps1:
        kmem_freepages(cachep, page);
 failed:
        if (gfpflags_allow_blocking(local_flags))
                local_irq_disable();
-       return 0;
+       return -1;
 }
 
 #if DEBUG
@@ -2916,14 +2917,14 @@ alloc_done:
                                return obj;
                }
 
-               x = cache_grow(cachep, gfp_exact_node(flags), node, NULL);
+               x = cache_grow(cachep, gfp_exact_node(flags), node);
 
                /* cache_grow can reenable interrupts, then ac could change. */
                ac = cpu_cache_get(cachep);
                node = numa_mem_id();
 
                /* no objects in sight? abort */
-               if (!x && ac->avail == 0)
+               if (x < 0 && ac->avail == 0)
                        return NULL;
 
                if (!ac->avail)         /* objects refilled by interrupt? */
@@ -3052,7 +3053,6 @@ static void *alternate_node_alloc(struct kmem_cache *cachep, gfp_t flags)
 static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
 {
        struct zonelist *zonelist;
-       gfp_t local_flags;
        struct zoneref *z;
        struct zone *zone;
        enum zone_type high_zoneidx = gfp_zone(flags);
@@ -3063,8 +3063,6 @@ static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
        if (flags & __GFP_THISNODE)
                return NULL;
 
-       local_flags = flags & (GFP_CONSTRAINT_MASK|GFP_RECLAIM_MASK);
-
 retry_cpuset:
        cpuset_mems_cookie = read_mems_allowed_begin();
        zonelist = node_zonelist(mempolicy_slab_node(), flags);
@@ -3094,33 +3092,17 @@ retry:
                 * We may trigger various forms of reclaim on the allowed
                 * set and go into memory reserves if necessary.
                 */
-               struct page *page;
+               nid = cache_grow(cache, flags, numa_mem_id());
+               if (nid >= 0) {
+                       obj = ____cache_alloc_node(cache,
+                               gfp_exact_node(flags), nid);
 
-               if (gfpflags_allow_blocking(local_flags))
-                       local_irq_enable();
-               kmem_flagcheck(cache, flags);
-               page = kmem_getpages(cache, local_flags, numa_mem_id());
-               if (gfpflags_allow_blocking(local_flags))
-                       local_irq_disable();
-               if (page) {
                        /*
-                        * Insert into the appropriate per node queues
+                        * Another processor may allocate the objects in
+                        * the slab since we are not holding any locks.
                         */
-                       nid = page_to_nid(page);
-                       if (cache_grow(cache, flags, nid, page)) {
-                               obj = ____cache_alloc_node(cache,
-                                       gfp_exact_node(flags), nid);
-                               if (!obj)
-                                       /*
-                                        * Another processor may allocate the
-                                        * objects in the slab since we are
-                                        * not holding any locks.
-                                        */
-                                       goto retry;
-                       } else {
-                               /* cache_grow already freed obj */
-                               obj = NULL;
-                       }
+                       if (!obj)
+                               goto retry;
                }
        }
 
@@ -3171,8 +3153,8 @@ retry:
 
 must_grow:
        spin_unlock(&n->list_lock);
-       x = cache_grow(cachep, gfp_exact_node(flags), nodeid, NULL);
-       if (x)
+       x = cache_grow(cachep, gfp_exact_node(flags), nodeid);
+       if (x >= 0)
                goto retry;
 
        return fallback_alloc(cachep, flags);