From 11c9ea4e80fc3be83485667204c68d0a732f3757 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 23 Mar 2011 16:42:34 -0700 Subject: [PATCH] memcg: convert per-cpu stock from bytes to page granularity We never keep subpage quantities in the per-cpu stock. Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Cc: Balbir Singh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 09a450684f70..91120a04f935 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1650,14 +1650,14 @@ EXPORT_SYMBOL(mem_cgroup_update_page_stat); #define CHARGE_SIZE (32 * PAGE_SIZE) struct memcg_stock_pcp { struct mem_cgroup *cached; /* this never be root cgroup */ - int charge; + unsigned int nr_pages; struct work_struct work; }; static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); static atomic_t memcg_drain_count; /* - * Try to consume stocked charge on this cpu. If success, PAGE_SIZE is consumed + * Try to consume stocked charge on this cpu. If success, one page is consumed * from local stock and true is returned. If the stock is 0 or charges from a * cgroup which is not current target, returns false. This stock will be * refilled. @@ -1668,8 +1668,8 @@ static bool consume_stock(struct mem_cgroup *mem) bool ret = true; stock = &get_cpu_var(memcg_stock); - if (mem == stock->cached && stock->charge) - stock->charge -= PAGE_SIZE; + if (mem == stock->cached && stock->nr_pages) + stock->nr_pages--; else /* need to call res_counter_charge */ ret = false; put_cpu_var(memcg_stock); @@ -1683,13 +1683,15 @@ static void drain_stock(struct memcg_stock_pcp *stock) { struct mem_cgroup *old = stock->cached; - if (stock->charge) { - res_counter_uncharge(&old->res, stock->charge); + if (stock->nr_pages) { + unsigned long bytes = stock->nr_pages * PAGE_SIZE; + + res_counter_uncharge(&old->res, bytes); if (do_swap_account) - res_counter_uncharge(&old->memsw, stock->charge); + res_counter_uncharge(&old->memsw, bytes); + stock->nr_pages = 0; } stock->cached = NULL; - stock->charge = 0; } /* @@ -1706,7 +1708,7 @@ static void drain_local_stock(struct work_struct *dummy) * Cache charges(val) which is from res_counter, to local per_cpu area. * This will be consumed by consume_stock() function, later. */ -static void refill_stock(struct mem_cgroup *mem, int val) +static void refill_stock(struct mem_cgroup *mem, unsigned int nr_pages) { struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock); @@ -1714,7 +1716,7 @@ static void refill_stock(struct mem_cgroup *mem, int val) drain_stock(stock); stock->cached = mem; } - stock->charge += val; + stock->nr_pages += nr_pages; put_cpu_var(memcg_stock); } @@ -2012,7 +2014,7 @@ again: } while (ret != CHARGE_OK); if (csize > page_size) - refill_stock(mem, csize - page_size); + refill_stock(mem, (csize - page_size) >> PAGE_SHIFT); css_put(&mem->css); done: *memcg = mem;