mm/slub: introduce helpers for node partial slab state

Wrap partial slab count inc/dec and flag set/clear into
helper functions to reduce code duplication.

Note that __add_partial() is called locklessly in
early_kmem_cache_node_alloc(), but since there is no such use case for
removal, __remove_partial() does not exist.

Suggested-by: Harry Yoo <harry@kernel.org>
Signed-off-by: Hao Li <hao.li@linux.dev>
Link: https://patch.msgid.link/20260529035120.81304-2-hao.li@linux.dev
Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org>
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>

diff --git a/mm/slub.c b/mm/slub.c
index cbf6636a3dad074a44c294434f3235b2f4a264c4..f9a4da5363564f56be6e0bcdeb534b65f77015f2 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3521,15 +3521,21 @@ static inline void slab_clear_node_partial(struct slab *slab)
 /*
  * Management of partially allocated slabs.
  */
+static inline void set_node_partial_state(struct kmem_cache_node *n,
+                                       struct slab *slab)
+{
+       slab_set_node_partial(slab);
+       n->nr_partial++;
+}
+
 static inline void
 __add_partial(struct kmem_cache_node *n, struct slab *slab, enum add_mode mode)
 {
-       n->nr_partial++;
        if (mode == ADD_TO_TAIL)
                list_add_tail(&slab->slab_list, &n->partial);
        else
                list_add(&slab->slab_list, &n->partial);
-       slab_set_node_partial(slab);
+       set_node_partial_state(n, slab);
 }
 
 static inline void add_partial(struct kmem_cache_node *n,
@@ -3539,13 +3545,19 @@ static inline void add_partial(struct kmem_cache_node *n,
        __add_partial(n, slab, mode);
 }
 
+static inline void clear_node_partial_state(struct kmem_cache_node *n,
+                                       struct slab *slab)
+{
+       slab_clear_node_partial(slab);
+       n->nr_partial--;
+}
+
 static inline void remove_partial(struct kmem_cache_node *n,
                                        struct slab *slab)
 {
        lockdep_assert_held(&n->list_lock);
        list_del(&slab->slab_list);
-       slab_clear_node_partial(slab);
-       n->nr_partial--;
+       clear_node_partial_state(n, slab);
 }
 
 /*
@@ -8266,8 +8278,7 @@ static int __kmem_cache_do_shrink(struct kmem_cache *s)
 
                        if (free == slab->objects) {
                                list_move(&slab->slab_list, &discard);
-                               slab_clear_node_partial(slab);
-                               n->nr_partial--;
+                               clear_node_partial_state(n, slab);
                                dec_slabs_node(s, node, slab->objects);
                        } else if (free <= SHRINK_PROMOTE_MAX)
                                list_move(&slab->slab_list, promote + free - 1);