On Fri, Apr 30, 2021 at 04:32:39PM +0800, Muchun Song wrote: > Before start, we should know about the following rules of list lrus. > > - Only objects allocated with __GFP_ACCOUNT need to allocate > the struct list_lru_node. > - The caller of allocating memory must know which list_lru the > object will insert. > > So we can allocate struct list_lru_node when allocating the > object instead of allocating it when list_lru_add(). It is easy, because > we already know the list_lru and memcg which the object belongs > to. So we can introduce a new helper to allocate the object and > list_lru_node. Like below. I feel like there may be a simpler solution, although I'm not really familiar with the list_lru situation. The three caches you mention: > I have looked at the code closely. There are 3 different kmem_caches that > need to use this new API to allocate memory. They are inode_cachep, > dentry_cache and radix_tree_node_cachep. I think that it is easy to migrate. are all filesystem. So if there's a way of knowing which filesystems are exposed to each container, we can allocate the list_lru structures at "mount" time rather than at first allocation for a given cache/lru/memcg combination.
