From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756712Ab0BOXsn (ORCPT <rfc822;w@1wt.eu>);
	Mon, 15 Feb 2010 18:48:43 -0500
Received: from ey-out-2122.google.com ([74.125.78.25]:33035 "EHLO
	ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1756283Ab0BOXsm (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 15 Feb 2010 18:48:42 -0500
MIME-Version: 1.0
In-Reply-To: <201002131133.43028.arnd@arndb.de>
References: <201002131133.43028.arnd@arndb.de>
Date: Mon, 15 Feb 2010 15:48:40 -0800
Message-ID: <9ae48b021002151548l79b8c5fdycc04a2f36fed1f09@mail.gmail.com>
Subject: Re: [PATCH 1/2] macvtap: rework object lifetime rules
From: Ed Swierk <eswierk@aristanetworks.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
       Patrick McHardy <kaber@trash.net>, Sridhar Samudrala <sri@us.ibm.com>,
       qemu-devel@nongnu.org, "Michael S. Tsirkin" <mst@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sat, Feb 13, 2010 at 2:33 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> The original macvtap code has a number of problems
> resulting from the use of RCU for protecting the
> access to struct macvtap_queue from open files.
>
> This includes
> - need for GFP_ATOMIC allocations for skbs
> - potential deadlocks when copy_*_user sleeps
> - inability to work with vhost-net
>
> Changing the lifetime of macvtap_queue to always
> depend on the open file solves all these. The
> RCU reference simply moves one step down to
> the reference on the macvlan_dev, which we
> only need for nonblocking operations.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

This works for me.

Acked-by: Ed Swierk <eswierk@aristanetworks.com>