Re: [PATCH v8 1/6] list_lru: allows explicit memcg and NUMA node selection

Matthew Wilcox
2023-11-30T19:58:03Z

On Thu, Nov 30, 2023 at 11:40:18AM -0800, Nhat Pham wrote:
> This patch changes list_lru interface so that the caller must explicitly
> specify numa node and memcg when adding and removing objects. The old
> list_lru_add() and list_lru_del() are renamed to list_lru_add_obj() and
> list_lru_del_obj(), respectively.

Wouldn't it be better to add list_lru_add_memcg() and
list_lru_del_memcg() and have:

+bool list_lru_del(struct list_lru *lru, struct list_head *item)
+{
+ int nid = page_to_nid(virt_to_page(item));
+ struct mem_cgroup *memcg = list_lru_memcg_aware(lru) ?
+ mem_cgroup_from_slab_obj(item) : NULL;
+
+ return list_lru_del_memcg(lru, item, nid, memcg);
+}

Seems like _most_ callers will want the original versions and only
a few will want the explicit memcg/nid versions. No?