From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx113.postini.com [74.125.245.113]) by kanga.kvack.org (Postfix) with SMTP id B76BC6B004D for ; Fri, 20 Jul 2012 04:10:46 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 393CF3EE0C0 for ; Fri, 20 Jul 2012 17:10:45 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 208BD45DE51 for ; Fri, 20 Jul 2012 17:10:45 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 09D3445DE4E for ; Fri, 20 Jul 2012 17:10:45 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id EFAFEE08005 for ; Fri, 20 Jul 2012 17:10:44 +0900 (JST) Received: from m1000.s.css.fujitsu.com (m1000.s.css.fujitsu.com [10.240.81.136]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id A110FE08001 for ; Fri, 20 Jul 2012 17:10:44 +0900 (JST) Message-ID: <500911EA.1030004@jp.fujitsu.com> Date: Fri, 20 Jul 2012 17:08:10 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: + hugetlb-cgroup-simplify-pre_destroy-callback.patch added to -mm tree References: <20120718212637.133475C0050@hpza9.eem.corp.google.com> <20120719113915.GC2864@tiehlicka.suse.cz> <87r4s8gcwe.fsf@skywalker.in.ibm.com> <20120719123820.GG2864@tiehlicka.suse.cz> <87ipdjc15j.fsf@skywalker.in.ibm.com> <5008AEC2.9090707@jp.fujitsu.com> <5008B25D.5000902@jp.fujitsu.com> <20120720080136.GB12434@tiehlicka.suse.cz> In-Reply-To: <20120720080136.GB12434@tiehlicka.suse.cz> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: "Aneesh Kumar K.V" , akpm@linux-foundation.org, mm-commits@vger.kernel.org, liwanp@linux.vnet.ibm.com, Tejun Heo , Li Zefan , cgroups mailinglist , linux-mm@kvack.org (2012/07/20 17:01), Michal Hocko wrote: > On Fri 20-07-12 10:20:29, KAMEZAWA Hiroyuki wrote: > [...] >> Hmm, can't cgroup_lock() be implemented as >> >> >> void cgroup_lock() >> { >> get_online_cpus() >> lock_memory_hotplug() >> mutex_lock(&cgroup_mutex); >> } > > This is really ugly and it wouldn't help much anyway. Notifier which > takes the cgroup_lock is called when cpu_hotplug.lock is held already. Hm ? IIUC, notifer will not work until put_online_cpu() is called. > You would need to call cgroup_lock() before taking the cpu_hotplug.lock > and remove it from notifiers. I think this should be doable but I didn't > have too much time to look deeper into it. > -- 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