From 6b3ae58efca06623c197fd6d91ded4aa3a8fe039 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 23 Mar 2011 16:42:30 -0700 Subject: memcg: remove direct page_cgroup-to-page pointer In struct page_cgroup, we have a full word for flags but only a few are reserved. Use the remaining upper bits to encode, depending on configuration, the node or the section, to enable page_cgroup-to-page lookups without a direct pointer. This saves a full word for every page in a system with memory cgroups enabled. Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Cc: Balbir Singh Cc: Minchan Kim Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/memcontrol.c') diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e286e1603e4..660dfc27d97 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1080,7 +1080,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, if (unlikely(!PageCgroupUsed(pc))) continue; - page = pc->page; + page = lookup_cgroup_page(pc); if (unlikely(!PageLRU(page))) continue; @@ -3344,7 +3344,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, } spin_unlock_irqrestore(&zone->lru_lock, flags); - page = pc->page; + page = lookup_cgroup_page(pc); ret = mem_cgroup_move_parent(page, pc, mem, GFP_KERNEL); if (ret == -ENOMEM) -- cgit v1.2.3