Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760852Ab3DCJNa (ORCPT ); Wed, 3 Apr 2013 05:13:30 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:39250 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759807Ab3DCJN1 (ORCPT ); Wed, 3 Apr 2013 05:13:27 -0400 Message-ID: <515BF296.3080406@huawei.com> Date: Wed, 3 Apr 2013 17:12:54 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130307 Thunderbird/17.0.4 MIME-Version: 1.0 To: CC: LKML , Cgroups , Tejun Heo , Glauber Costa , Michal Hocko , KAMEZAWA Hiroyuki , Johannes Weiner Subject: [RFC][PATCH 4/7] memcg: use css_get/put for swap memcg References: <515BF233.6070308@huawei.com> In-Reply-To: <515BF233.6070308@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.135.68.215] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3456 Lines: 98 Use css_get/put instead of mem_cgroup_get/put. Signed-off-by: Li Zefan --- mm/memcontrol.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 877551d..ad576e8 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4137,12 +4137,12 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype, unlock_page_cgroup(pc); /* * even after unlock, we have memcg->res.usage here and this memcg - * will never be freed. + * will never be freed, so it's safe to call css_get(). */ memcg_check_events(memcg, page); if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) { mem_cgroup_swap_statistics(memcg, true); - mem_cgroup_get(memcg); + css_get(&memcg->css); } /* * Migration does not charge the res_counter for the @@ -4242,7 +4242,7 @@ mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout) /* * record memcg information, if swapout && memcg != NULL, - * mem_cgroup_get() was called in uncharge(). + * css_get() was called in uncharge(). */ if (do_swap_account && swapout && memcg) swap_cgroup_record(ent, css_id(&memcg->css)); @@ -4273,7 +4273,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent) if (!mem_cgroup_is_root(memcg)) res_counter_uncharge(&memcg->memsw, PAGE_SIZE); mem_cgroup_swap_statistics(memcg, false); - mem_cgroup_put(memcg); + css_put(&memcg->css); } rcu_read_unlock(); } @@ -4307,11 +4307,14 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry, * This function is only called from task migration context now. * It postpones res_counter and refcount handling till the end * of task migration(mem_cgroup_clear_mc()) for performance - * improvement. But we cannot postpone mem_cgroup_get(to) - * because if the process that has been moved to @to does - * swap-in, the refcount of @to might be decreased to 0. + * improvement. But we cannot postpone css_get(to) because if + * the process that has been moved to @to does swap-in, the + * refcount of @to might be decreased to 0. + * + * We are in attach() phase, so the cgroup is guaranteed to be + * alive, so we can just call css_get(). */ - mem_cgroup_get(to); + css_get(&to->css); return 0; } return -EINVAL; @@ -6597,6 +6600,7 @@ static void __mem_cgroup_clear_mc(void) { struct mem_cgroup *from = mc.from; struct mem_cgroup *to = mc.to; + int i; /* we must uncharge all the leftover precharges from mc.to */ if (mc.precharge) { @@ -6617,7 +6621,9 @@ static void __mem_cgroup_clear_mc(void) if (!mem_cgroup_is_root(mc.from)) res_counter_uncharge(&mc.from->memsw, PAGE_SIZE * mc.moved_swap); - __mem_cgroup_put(mc.from, mc.moved_swap); + + for (i = 0; i < mc.moved_swap; i++) + css_put(&mc.from->css); if (!mem_cgroup_is_root(mc.to)) { /* @@ -6627,7 +6633,7 @@ static void __mem_cgroup_clear_mc(void) res_counter_uncharge(&mc.to->res, PAGE_SIZE * mc.moved_swap); } - /* we've already done mem_cgroup_get(mc.to) */ + /* we've already done css_get(mc.to) */ mc.moved_swap = 0; } memcg_oom_recover(from); -- 1.8.0.2 -- 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/