mm: collect LRU list heads into struct lruvec

Having a unified structure with a LRU list set for both global zones and
per-memcg zones allows to keep that code simple which deals with LRU
lists and does not care about the container itself.

Once the per-memcg LRU lists directly link struct pages, the isolation
function and all other list manipulations are shared between the memcg
case and the global LRU case.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Ying Han <yinghan@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 10 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ad7f36f676ff..6e7f849a1a9e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -134,10 +134,7 @@ struct mem_cgroup_reclaim_iter {
  * per-zone information in memory controller.
  */
 struct mem_cgroup_per_zone {
-	/*
-	 * spin_lock to protect the per cgroup LRU
-	 */
-	struct list_head	lists[NR_LRU_LISTS];
+	struct lruvec		lruvec;
 	unsigned long		count[NR_LRU_LISTS];
 
 	struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
@@ -1061,7 +1058,7 @@ void mem_cgroup_rotate_reclaimable_page(struct page *page)
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move_tail(&pc->lru, &mz->lists[lru]);
+	list_move_tail(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
@@ -1079,7 +1076,7 @@ void mem_cgroup_rotate_lru_list(struct page *page, enum lru_list lru)
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
 	smp_rmb();
 	mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
-	list_move(&pc->lru, &mz->lists[lru]);
+	list_move(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
@@ -1109,7 +1106,7 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 	/* huge page split is done under lru_lock. so, we have no races. */
 	MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
 	SetPageCgroupAcctLRU(pc);
-	list_add(&pc->lru, &mz->lists[lru]);
+	list_add(&pc->lru, &mz->lruvec.lists[lru]);
 }
 
 /*
@@ -1307,7 +1304,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
 
 	BUG_ON(!mem_cont);
 	mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
-	src = &mz->lists[lru];
+	src = &mz->lruvec.lists[lru];
 
 	scan = 0;
 	list_for_each_entry_safe_reverse(pc, tmp, src, lru) {
@@ -3738,7 +3735,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
 
 	zone = &NODE_DATA(node)->node_zones[zid];
 	mz = mem_cgroup_zoneinfo(memcg, node, zid);
-	list = &mz->lists[lru];
+	list = &mz->lruvec.lists[lru];
 
 	loop = MEM_CGROUP_ZSTAT(mz, lru);
 	/* give some margin against EBUSY etc...*/
@@ -4864,7 +4861,7 @@ static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
 	for (zone = 0; zone < MAX_NR_ZONES; zone++) {
 		mz = &pn->zoneinfo[zone];
 		for_each_lru(l)
-			INIT_LIST_HEAD(&mz->lists[l]);
+			INIT_LIST_HEAD(&mz->lruvec.lists[l]);
 		mz->usage_in_excess = 0;
 		mz->on_tree = false;
 		mz->mem = memcg;