From 867e5e1de14b2b2bde324cdfeec3f3f83eb21424 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Sat, 30 Nov 2019 17:55:34 -0800 Subject: mm: clean up and clarify lruvec lookup procedure There is a per-memcg lruvec and a NUMA node lruvec. Which one is being used is somewhat confusing right now, and it's easy to make mistakes - especially when it comes to global reclaim. How it works: when memory cgroups are enabled, we always use the root_mem_cgroup's per-node lruvecs. When memory cgroups are not compiled in or disabled at runtime, we use pgdat->lruvec. Document that in a comment. Due to the way the reclaim code is generalized, all lookups use the mem_cgroup_lruvec() helper function, and nobody should have to find the right lruvec manually right now. But to avoid future mistakes, rename the pgdat->lruvec member to pgdat->__lruvec and delete the convenience wrapper that suggests it's a commonly accessed member. While in this area, swap the mem_cgroup_lruvec() argument order. The name suggests a memcg operation, yet it takes a pgdat first and a memcg second. I have to double take every time I call this. Fix that. Link: http://lkml.kernel.org/r/20191022144803.302233-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Reviewed-by: Shakeel Butt Cc: Roman Gushchin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/workingset.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'mm/workingset.c') diff --git a/mm/workingset.c b/mm/workingset.c index c963831d354f..e8212123c1c3 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -233,7 +233,7 @@ void *workingset_eviction(struct page *page) VM_BUG_ON_PAGE(page_count(page), page); VM_BUG_ON_PAGE(!PageLocked(page), page); - lruvec = mem_cgroup_lruvec(pgdat, memcg); + lruvec = mem_cgroup_lruvec(memcg, pgdat); eviction = atomic_long_inc_return(&lruvec->inactive_age); return pack_shadow(memcgid, pgdat, eviction, PageWorkingset(page)); } @@ -280,7 +280,7 @@ void workingset_refault(struct page *page, void *shadow) memcg = mem_cgroup_from_id(memcgid); if (!mem_cgroup_disabled() && !memcg) goto out; - lruvec = mem_cgroup_lruvec(pgdat, memcg); + lruvec = mem_cgroup_lruvec(memcg, pgdat); refault = atomic_long_read(&lruvec->inactive_age); active_file = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE, MAX_NR_ZONES); @@ -345,7 +345,7 @@ void workingset_activation(struct page *page) memcg = page_memcg_rcu(page); if (!mem_cgroup_disabled() && !memcg) goto out; - lruvec = mem_cgroup_lruvec(page_pgdat(page), memcg); + lruvec = mem_cgroup_lruvec(memcg, page_pgdat(page)); atomic_long_inc(&lruvec->inactive_age); out: rcu_read_unlock(); @@ -426,7 +426,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, struct lruvec *lruvec; int i; - lruvec = mem_cgroup_lruvec(NODE_DATA(sc->nid), sc->memcg); + lruvec = mem_cgroup_lruvec(sc->memcg, NODE_DATA(sc->nid)); for (pages = 0, i = 0; i < NR_LRU_LISTS; i++) pages += lruvec_page_state_local(lruvec, NR_LRU_BASE + i); -- cgit v1.2.3