[PATCH v2] ifb: make device count build-time configurable
From: Lubomir Rintel <lkundrak@v3.sk>
Date: 2016-01-12 15:37:04
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Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <lkundrak@v3.sk>
---
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");
--
2.5.0