[PATCH v6 04/10] mm,slub: Use node-notifier instead of memory-notifier

Oscar Salvador
2025-06-09T09:22:07Z

slub is only concerned when a numa node changes its memory state,
so stop using the memory notifier and use the new numa node notifer
instead.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
---
mm/slub.c | 28 +++++++++-------------------
1 file changed, 9 insertions(+), 19 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index f92b43d36adc..3ff0b94f3eeb 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -6146,7 +6146,7 @@ int __kmem_cache_shrink(struct kmem_cache *s)
return __kmem_cache_do_shrink(s);
}

-static int slab_mem_going_offline_callback(void *arg)
+static int slab_mem_going_offline_callback(void)
{
struct kmem_cache *s;

@@ -6160,21 +6160,12 @@ static int slab_mem_going_offline_callback(void *arg)
return 0;
}

-static int slab_mem_going_online_callback(void *arg)
+static int slab_mem_going_online_callback(int nid)
{
struct kmem_cache_node *n;
struct kmem_cache *s;
- struct memory_notify *marg = arg;
- int nid = marg->status_change_nid;
int ret = 0;

- /*
- * If the node's memory is already available, then kmem_cache_node is
- * already created. Nothing to do.
- */
- if (nid < 0)
- return 0;
-
/*
* We are bringing a node online. No memory is available yet. We must
* allocate a kmem_cache_node structure in order to bring the node
@@ -6214,17 +6205,16 @@ static int slab_mem_going_online_callback(void *arg)
static int slab_memory_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
+ struct node_notify *nn = arg;
+ int nid = nn->nid;
int ret = 0;

switch (action) {
- case MEM_GOING_ONLINE:
- ret = slab_mem_going_online_callback(arg);
- break;
- case MEM_GOING_OFFLINE:
- ret = slab_mem_going_offline_callback(arg);
+ case NODE_ADDING_FIRST_MEMORY:
+ ret = slab_mem_going_online_callback(nid);
break;
- case MEM_ONLINE:
- case MEM_CANCEL_OFFLINE:
+ case NODE_REMOVING_LAST_MEMORY:
+ ret = slab_mem_going_offline_callback();
break;
}
if (ret)
@@ -6300,7 +6290,7 @@ void __init kmem_cache_init(void)
sizeof(struct kmem_cache_node),
SLAB_HWCACHE_ALIGN | SLAB_NO_OBJ_EXT, 0, 0);

- hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
+ hotplug_node_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);

/* Able to allocate the per node structures */
slab_state = PARTIAL;
--
2.49.0