From patchwork Tue Jan 12 15:36:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lubomir Rintel X-Patchwork-Id: 566605 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 8622A140C65 for ; Wed, 13 Jan 2016 02:37:29 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762772AbcALPhE (ORCPT ); Tue, 12 Jan 2016 10:37:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53295 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752801AbcALPhC (ORCPT ); Tue, 12 Jan 2016 10:37:02 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id DC75C6E799; Tue, 12 Jan 2016 15:37:01 +0000 (UTC) Received: from belphegor.brq.redhat.com (dhcp-0-167.brq.redhat.com [10.34.0.167]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u0CFavDA024428 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 12 Jan 2016 10:37:00 -0500 From: Lubomir Rintel To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "David S. Miller" , Jamal Hadi Salim , Daniel Borkmann , Lubomir Rintel Subject: [PATCH v2] ifb: make device count build-time configurable Date: Tue, 12 Jan 2016 16:36:51 +0100 Message-Id: <1452613011-2971-1-git-send-email-lkundrak@v3.sk> In-Reply-To: <1452612711.18559.62.camel@v3.sk> References: <1452612711.18559.62.camel@v3.sk> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The devices can be created at run-time for quite some time already and the load-time device creation collides with attempts to create the device of the same name: # rmmod ifb # ip link add ifb0 type ifb RTNETLINK answers: File exists This is pretty much the same situation as was with the block loop devices which was solved by adding a build-time configuration that the distributions could use as they deem fit while keeping the default for compatibility. Let's do that here as well. Signed-off-by: Lubomir Rintel --- Changes since v1: - The default number of devices is 2 not 3. drivers/net/Kconfig | 21 +++++++++++++++++---- drivers/net/ifb.c | 2 +- 2 files changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index f184fb5..bb40d30 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -110,12 +110,25 @@ config IFB This is an intermediate driver that allows sharing of resources. To compile this driver as a module, choose M here: the module - will be called ifb. If you want to use more than one ifb - device at a time, you need to compile this driver as a module. - Instead of 'ifb', the devices will then be called 'ifb0', - 'ifb1' etc. + will be called ifb. + Look at the iproute2 documentation directory for usage etc +config IFB_COUNT + int "Number of ifb devices to pre-create at init time" + depends on IFB + default 2 + help + Static number of ifb devices to be unconditionally pre-created + at init time. + + This default value can be overwritten on the kernel command + line or with module-parameter ifb.numifbs. + + The historic default is 3. If a mid-2007 version of iproute2 + is used (v2.6.23 or later), it can be set to 0, since needed + ifb devices can be dynamically allocated via rtnetlink. + source "drivers/net/team/Kconfig" config MACVLAN diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c index cc56fac..911af2c 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -298,7 +298,7 @@ static struct rtnl_link_ops ifb_link_ops __read_mostly = { * Note that these legacy devices have one queue. * Prefer something like : ip link add ifb10 numtxqueues 8 type ifb */ -static int numifbs = 2; +static int numifbs = CONFIG_IFB_COUNT; module_param(numifbs, int, 0); MODULE_PARM_DESC(numifbs, "Number of ifb devices");