From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 554D36B0044 for ; Tue, 15 Dec 2009 18:59:06 -0500 (EST) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id nBFNx2El016447 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 16 Dec 2009 08:59:02 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 9922B45DE50 for ; Wed, 16 Dec 2009 08:59:02 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 76BA545DE4F for ; Wed, 16 Dec 2009 08:59:02 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 588B41DB8038 for ; Wed, 16 Dec 2009 08:59:02 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id F02321DB803A for ; Wed, 16 Dec 2009 08:59:01 +0900 (JST) Date: Wed, 16 Dec 2009 08:55:52 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH RFC v2 1/4] cgroup: implement eventfd-based generic API for notifications Message-Id: <20091216085552.91ebc559.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20091215183533.1a1e87d9.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org To: "Kirill A. Shutemov" Cc: Paul Menage , Li Zefan , containers@lists.linux-foundation.org, Andrew Morton , Balbir Singh , Pavel Emelyanov , Dan Malek , Vladislav Buzov , Daisuke Nishimura , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Tue, 15 Dec 2009 17:03:37 +0200 "Kirill A. Shutemov" wrote: > >> > + A A A /* > >> > + A A A A * Unregister events and notify userspace. > >> > + A A A A * FIXME: How to avoid race with cgroup_event_remove_work() > >> > + A A A A * A A A A which runs from workqueue? > >> > + A A A A */ > >> > + A A A mutex_lock(&cgrp->event_list_mutex); > >> > + A A A list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) { > >> > + A A A A A A A cgroup_event_remove(event); > >> > + A A A A A A A eventfd_signal(event->eventfd, 1); > >> > + A A A } > >> > + A A A mutex_unlock(&cgrp->event_list_mutex); > >> > + > >> > +out: > >> > A A A A return ret; > >> > A } > > > > How ciritical is this FIXME ? > > But Hmm..can't we use RCU ? > > It's not reasonable to have RCU here, since event_list isn't mostly-read. > ok. Thanks, -Kame -- 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