From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx127.postini.com [74.125.245.127]) by kanga.kvack.org (Postfix) with SMTP id 546326B0031 for ; Mon, 29 Jul 2013 21:13:13 -0400 (EDT) Message-ID: <51F7127B.1070107@huawei.com> Date: Tue, 30 Jul 2013 09:10:19 +0800 From: Li Zefan MIME-Version: 1.0 Subject: Re: [PATCH v3 1/8] cgroup: convert cgroup_ida to cgroup_idr References: <51F614B2.6010503@huawei.com> <51F614C4.7060602@huawei.com> <20130729182835.GD26076@mtj.dyndns.org> In-Reply-To: <20130729182835.GD26076@mtj.dyndns.org> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Andrew Morton , Glauber Costa , KAMEZAWA Hiroyuki , Michal Hocko , Johannes Weiner , LKML , Cgroups , linux-mm@kvack.org On 2013/7/30 2:28, Tejun Heo wrote: > Hello, > > On Mon, Jul 29, 2013 at 03:07:48PM +0800, Li Zefan wrote: >> @@ -4590,6 +4599,9 @@ static void cgroup_offline_fn(struct work_struct *work) >> /* delete this cgroup from parent->children */ >> list_del_rcu(&cgrp->sibling); >> >> + if (cgrp->id) >> + idr_remove(&cgrp->root->cgroup_idr, cgrp->id); >> + > > Yeap, if we're gonna allow lookups, removal should happen here but can > we please add short comment explaining why that is? sure > Also, do we want to clear cgrp->id? > Set cgrp->id to 0? No, 0 is a valid id. The if is here because at first I called idr_alloc() very late in cgroup_create(), so cgroup_offline_fn() can be called while cgrp->id hasn't been initialized. Now I can remove this check. -- 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/ . Don't email: email@kvack.org