Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752027Ab2JHKGy (ORCPT ); Mon, 8 Oct 2012 06:06:54 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:7266 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751911Ab2JHKGv (ORCPT ); Mon, 8 Oct 2012 06:06:51 -0400 From: Glauber Costa To: Cc: , Andrew Morton , Mel Gorman , Suleiman Souhlal , Tejun Heo , , , Michal Hocko , Johannes Weiner , Greg Thelen , , Frederic Weisbecker , Glauber Costa Subject: [PATCH v4 01/14] memcg: Make it possible to use the stock for more than one page. Date: Mon, 8 Oct 2012 14:06:07 +0400 Message-Id: <1349690780-15988-2-git-send-email-glommer@parallels.com> X-Mailer: git-send-email 1.7.11.4 In-Reply-To: <1349690780-15988-1-git-send-email-glommer@parallels.com> References: <1349690780-15988-1-git-send-email-glommer@parallels.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3150 Lines: 89 From: Suleiman Souhlal We currently have a percpu stock cache scheme that charges one page at a time from memcg->res, the user counter. When the kernel memory controller comes into play, we'll need to charge more than that. This is because kernel memory allocations will also draw from the user counter, and can be bigger than a single page, as it is the case with the stack (usually 2 pages) or some higher order slabs. [ glommer@parallels.com: added a changelog ] Signed-off-by: Suleiman Souhlal Signed-off-by: Glauber Costa Acked-by: David Rientjes Acked-by: Kamezawa Hiroyuki Acked-by: Michal Hocko Acked-by: Johannes Weiner --- mm/memcontrol.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7acf43b..47cb019 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2028,20 +2028,28 @@ struct memcg_stock_pcp { static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); static DEFINE_MUTEX(percpu_charge_mutex); -/* - * 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. +/** + * consume_stock: Try to consume stocked charge on this cpu. + * @memcg: memcg to consume from. + * @nr_pages: how many pages to charge. + * + * The charges will only happen if @memcg matches the current cpu's memcg + * stock, and at least @nr_pages are available in that stock. Failure to + * service an allocation will refill the stock. + * + * returns true if succesfull, false otherwise. */ -static bool consume_stock(struct mem_cgroup *memcg) +static bool consume_stock(struct mem_cgroup *memcg, int nr_pages) { struct memcg_stock_pcp *stock; bool ret = true; + if (nr_pages > CHARGE_BATCH) + return false; + stock = &get_cpu_var(memcg_stock); - if (memcg == stock->cached && stock->nr_pages) - stock->nr_pages--; + if (memcg == stock->cached && stock->nr_pages >= nr_pages) + stock->nr_pages -= nr_pages; else /* need to call res_counter_charge */ ret = false; put_cpu_var(memcg_stock); @@ -2340,7 +2348,7 @@ again: VM_BUG_ON(css_is_removed(&memcg->css)); if (mem_cgroup_is_root(memcg)) goto done; - if (nr_pages == 1 && consume_stock(memcg)) + if (consume_stock(memcg, nr_pages)) goto done; css_get(&memcg->css); } else { @@ -2365,7 +2373,7 @@ again: rcu_read_unlock(); goto done; } - if (nr_pages == 1 && consume_stock(memcg)) { + if (consume_stock(memcg, nr_pages)) { /* * It seems dagerous to access memcg without css_get(). * But considering how consume_stok works, it's not -- 1.7.11.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/