From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx152.postini.com [74.125.245.152]) by kanga.kvack.org (Postfix) with SMTP id 62A226B007E for ; Fri, 27 Apr 2012 02:08:26 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id E5AA73EE0C0 for ; Fri, 27 Apr 2012 15:08:24 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id C02AE45DEBE for ; Fri, 27 Apr 2012 15:08:24 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 954EC45DEBC for ; Fri, 27 Apr 2012 15:08:24 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 854F41DB8043 for ; Fri, 27 Apr 2012 15:08:24 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.240.81.147]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 32D061DB8041 for ; Fri, 27 Apr 2012 15:08:24 +0900 (JST) Message-ID: <4F9A375D.7@jp.fujitsu.com> Date: Fri, 27 Apr 2012 15:06:21 +0900 From: KAMEZAWA Hiroyuki MIME-Version: 1.0 Subject: [RFC][PATCH 9/9 v2] memcg: never return error at pre_destroy() References: <4F9A327A.6050409@jp.fujitsu.com> In-Reply-To: <4F9A327A.6050409@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Linux Kernel Cc: "linux-mm@kvack.org" , "cgroups@vger.kernel.org" , Michal Hocko , Johannes Weiner , Frederic Weisbecker , Glauber Costa , Tejun Heo , Han Ying , "Aneesh Kumar K.V" , Andrew Morton , kamezawa.hiroyuki@gmail.com When force_empty() called by ->pre_destroy(), no memory reclaim happens and it doesn't take very long time which requires signal_pending() check. And if we return -EINTR from pre_destroy(), cgroup.c show warning. This patch removes signal check in force_empty(). By this, ->pre_destroy() returns success always. Note: check for 'cgroup is empty' remains for force_empty interface. Signed-off-by: KAMEZAWA Hiroyuki --- mm/hugetlb.c | 10 +--------- mm/memcontrol.c | 14 +++++--------- 2 files changed, 6 insertions(+), 18 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 4dd6b39..770f1642 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1922,20 +1922,12 @@ int hugetlb_force_memcg_empty(struct cgroup *cgroup) int ret = 0, idx = 0; do { + /* see memcontrol.c::mem_cgroup_force_empty() */ if (cgroup_task_count(cgroup) || !list_empty(&cgroup->children)) { ret = -EBUSY; goto out; } - /* - * If the task doing the cgroup_rmdir got a signal - * we don't really need to loop till the hugetlb resource - * usage become zero. - */ - if (signal_pending(current)) { - ret = -EINTR; - goto out; - } for_each_hstate(h) { spin_lock(&hugetlb_lock); list_for_each_entry(page, &h->hugepage_activelist, lru) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2715223..ee350c5 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3852,8 +3852,6 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, pc = lookup_page_cgroup(page); ret = mem_cgroup_move_parent(page, pc, memcg, GFP_KERNEL); - if (ret == -ENOMEM || ret == -EINTR) - break; if (ret == -EBUSY || ret == -EINVAL) { /* found lock contention or "pc" is obsolete. */ @@ -3863,7 +3861,7 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, busy = NULL; } - if (!ret && !list_empty(list)) + if (!loop) return -EBUSY; return ret; } @@ -3893,11 +3891,12 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg, bool free_all) move_account: do { ret = -EBUSY; + /* + * This never happens when this is called by ->pre_destroy(). + * But we need to take care of force_empty interface. + */ if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children)) goto out; - ret = -EINTR; - if (signal_pending(current)) - goto out; /* This is for making all *used* pages to be on LRU. */ lru_add_drain_all(); drain_all_stock_sync(memcg); @@ -3918,9 +3917,6 @@ move_account: } mem_cgroup_end_move(memcg); memcg_oom_recover(memcg); - /* it seems parent cgroup doesn't have enough mem */ - if (ret == -ENOMEM) - goto try_to_free; cond_resched(); /* "ret" should also be checked to ensure all lists are empty. */ } while (res_counter_read_u64(&memcg->res, RES_USAGE) > 0 || ret); -- 1.7.4.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org