From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753402AbZAEHP6 (ORCPT ); Mon, 5 Jan 2009 02:15:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751356AbZAEHPu (ORCPT ); Mon, 5 Jan 2009 02:15:50 -0500 Received: from mail-bw0-f21.google.com ([209.85.218.21]:49770 "EHLO mail-bw0-f21.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751287AbZAEHPt (ORCPT ); Mon, 5 Jan 2009 02:15:49 -0500 Message-ID: <4961B3A1.3070009@colorfullife.com> Date: Mon, 05 Jan 2009 08:15:45 +0100 From: Manfred Spraul User-Agent: Thunderbird 2.0.0.18 (X11/20081119) MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com CC: Lai Jiangshan , linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: Re: [RFC, PATCH] kernel/rcu: add kfree_rcu References: <200901021159.n02BxDLg024728@mail.q-ag.de> <20090102185543.GE6842@linux.vnet.ibm.com> <49604E19.8040502@cn.fujitsu.com> <20090104194851.GM6958@linux.vnet.ibm.com> In-Reply-To: <20090104194851.GM6958@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul E. McKenney wrote: > >> I think these two are different questions. >> vfree() still can not be called from softirq context now. >> And I proposed vfree_atomic() for RCU, but it can not be accepted. >> > > And one would indeed either need to have a vfree_atomic() or have some > mechanism that sent the vfree() to a workqueue or some such. > ipc/util.c uses a workqueue (ipc_schedule_free): The semaphore array structure can be large (documented with SEMMSL=8000 around 16 kB, but there is no hard limit), thus vmalloc is used. But as long as there are just one or two users, I doubt that a generic system is worth the effort. -- Manfred