slub: move min_partial to struct kmem_cache

Although it allows for better cacheline use, it is unnecessary to save a
copy of the cache's min_partial value in each kmem_cache_node.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

2 files changed, 17 insertions, 14 deletions

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 2f5c16b1aacd..f20a89e4d52c 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -46,7 +46,6 @@ struct kmem_cache_cpu {
 struct kmem_cache_node {
         spinlock_t list_lock;   /* Protect partial list and nr_partial */
         unsigned long nr_partial;
-        unsigned long min_partial;
         struct list_head partial;
 #ifdef CONFIG_SLUB_DEBUG
         atomic_long_t nr_slabs;
@@ -89,6 +88,7 @@ struct kmem_cache {
         void (*ctor)(void *);
         int inuse;              /* Offset to metadata */
         int align;              /* Alignment */
+        unsigned long min_partial;
         const char *name;       /* Name (only for display!) */
         struct list_head list;  /* List of slab caches */
 #ifdef CONFIG_SLUB_DEBUG
diff --git a/mm/slub.c b/mm/slub.c
index bdc9abb08a23..4fff385b17a3 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1335,7 +1335,7 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
                 n = get_node(s, zone_to_nid(zone));
 
                 if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
-                                n->nr_partial > n->min_partial) {
+                                n->nr_partial > s->min_partial) {
                         page = get_partial_node(n);
                         if (page)
                                 return page;
@@ -1387,7 +1387,7 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
                 slab_unlock(page);
         } else {
                 stat(c, DEACTIVATE_EMPTY);
-                if (n->nr_partial < n->min_partial) {
+                if (n->nr_partial < s->min_partial) {
                         /*
                          * Adding an empty slab to the partial slabs in order
                          * to avoid page allocator overhead. This slab needs
@@ -1928,17 +1928,6 @@ static void
 init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
 {
         n->nr_partial = 0;
-
-        /*
-         * The larger the object size is, the more pages we want on the partial
-         * list to avoid pounding the page allocator excessively.
-         */
-        n->min_partial = ilog2(s->size);
-        if (n->min_partial < MIN_PARTIAL)
-                n->min_partial = MIN_PARTIAL;
-        else if (n->min_partial > MAX_PARTIAL)
-                n->min_partial = MAX_PARTIAL;
-
         spin_lock_init(&n->list_lock);
         INIT_LIST_HEAD(&n->partial);
 #ifdef CONFIG_SLUB_DEBUG
@@ -2181,6 +2170,15 @@ static int init_kmem_cache_nodes(struct kmem_cache *s, gfp_t gfpflags)
 }
 #endif
 
+static void calculate_min_partial(struct kmem_cache *s, unsigned long min)
+{
+        if (min < MIN_PARTIAL)
+                min = MIN_PARTIAL;
+        else if (min > MAX_PARTIAL)
+                min = MAX_PARTIAL;
+        s->min_partial = min;
+}
+
 /*
  * calculate_sizes() determines the order and the distribution of data within
  * a slab object.
@@ -2319,6 +2317,11 @@ static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags,
         if (!calculate_sizes(s, -1))
                 goto error;
 
+        /*
+         * The larger the object size is, the more pages we want on the partial
+         * list to avoid pounding the page allocator excessively.
+         */
+        calculate_min_partial(s, ilog2(s->size));
         s->refcount = 1;
 #ifdef CONFIG_NUMA
         s->remote_node_defrag_ratio = 1000;