Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932347AbbEZONs (ORCPT ); Tue, 26 May 2015 10:13:48 -0400 Received: from cantor2.suse.de ([195.135.220.15]:44167 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755610AbbEZONl (ORCPT ); Tue, 26 May 2015 10:13:41 -0400 From: Michal Hocko To: Cc: Johannes Weiner , Oleg Nesterov , Tejun Heo , Vladimir Davydov , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Andrew Morton , LKML Subject: [RFC 1/3] memcg: restructure mem_cgroup_can_attach() Date: Tue, 26 May 2015 13:50:04 +0200 Message-Id: <1432641006-8025-2-git-send-email-mhocko@suse.cz> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1432641006-8025-1-git-send-email-mhocko@suse.cz> References: <1432641006-8025-1-git-send-email-mhocko@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2820 Lines: 106 From: Tejun Heo Restructure it to lower nesting level and help the planned threadgroup leader iteration changes. This is pure reorganization. Signed-off-by: Tejun Heo Cc: Johannes Weiner Acked-by: Michal Hocko --- mm/memcontrol.c | 61 ++++++++++++++++++++++++++++++--------------------------- 1 file changed, 32 insertions(+), 29 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5fd273d22714..f3d92cf0caf4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5001,10 +5001,12 @@ static void mem_cgroup_clear_mc(void) static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, struct cgroup_taskset *tset) { - struct task_struct *p = cgroup_taskset_first(tset); - int ret = 0; struct mem_cgroup *memcg = mem_cgroup_from_css(css); + struct mem_cgroup *from; + struct task_struct *p; + struct mm_struct *mm; unsigned long move_flags; + int ret = 0; /* * We are now commited to this value whatever it is. Changes in this @@ -5012,36 +5014,37 @@ static int mem_cgroup_can_attach(struct cgroup_subsys_state *css, * So we need to save it, and keep it going. */ move_flags = READ_ONCE(memcg->move_charge_at_immigrate); - if (move_flags) { - struct mm_struct *mm; - struct mem_cgroup *from = mem_cgroup_from_task(p); + if (!move_flags) + return 0; - VM_BUG_ON(from == memcg); + p = cgroup_taskset_first(tset); + from = mem_cgroup_from_task(p); - mm = get_task_mm(p); - if (!mm) - return 0; - /* We move charges only when we move a owner of the mm */ - if (mm->owner == p) { - VM_BUG_ON(mc.from); - VM_BUG_ON(mc.to); - VM_BUG_ON(mc.precharge); - VM_BUG_ON(mc.moved_charge); - VM_BUG_ON(mc.moved_swap); - - spin_lock(&mc.lock); - mc.from = from; - mc.to = memcg; - mc.flags = move_flags; - spin_unlock(&mc.lock); - /* We set mc.moving_task later */ - - ret = mem_cgroup_precharge_mc(mm); - if (ret) - mem_cgroup_clear_mc(); - } - mmput(mm); + VM_BUG_ON(from == memcg); + + mm = get_task_mm(p); + if (!mm) + return 0; + /* We move charges only when we move a owner of the mm */ + if (mm->owner == p) { + VM_BUG_ON(mc.from); + VM_BUG_ON(mc.to); + VM_BUG_ON(mc.precharge); + VM_BUG_ON(mc.moved_charge); + VM_BUG_ON(mc.moved_swap); + + spin_lock(&mc.lock); + mc.from = from; + mc.to = memcg; + mc.flags = move_flags; + spin_unlock(&mc.lock); + /* We set mc.moving_task later */ + + ret = mem_cgroup_precharge_mc(mm); + if (ret) + mem_cgroup_clear_mc(); } + mmput(mm); return ret; } -- 2.1.4 -- 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/