From: Mahesh Bandewar <maheshb@google.com>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>,
David Miller <davem@davemloft.net>,
Laurent Chavey <chavey@google.com>,
Tom Herbert <therbert@google.com>,
netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH v2] net: Allow ethtool to set interface in loopback mode.
Date: Tue, 4 Jan 2011 17:39:23 -0800 [thread overview]
Message-ID: <AANLkTim6VUBkT9NRX3jcufpXatNb9RLJbKZYCkVarFuX@mail.gmail.com> (raw)
In-Reply-To: <20110104172939.711b758d@nehalam>
On Tue, Jan 4, 2011 at 5:29 PM, Stephen Hemminger <shemminger@vyatta.com> wrote:
> On Wed, 05 Jan 2011 01:21:44 +0000
> Ben Hutchings <bhutchings@solarflare.com> wrote:
>
>> On Tue, 2011-01-04 at 16:36 -0800, Stephen Hemminger wrote:
>> > On Tue, 4 Jan 2011 16:30:01 -0800
>> > Mahesh Bandewar <maheshb@google.com> wrote:
>> >
>> > > This patch enables ethtool to set the loopback mode on a given interface.
>> > > By configuring the interface in loopback mode in conjunction with a policy
>> > > route / rule, a userland application can stress the egress / ingress path
>> > > exposing the flows of the change in progress and potentially help developer(s)
>> > > understand the impact of those changes without even sending a packet out
>> > > on the network.
>> > >
>> > > Following set of commands illustrates one such example -
>> > > a) ip -4 addr add 192.168.1.1/24 dev eth1
>> > > b) ip -4 rule add from all iif eth1 lookup 250
>> > > c) ip -4 route add local 0/0 dev lo proto kernel scope host table 250
>> > > d) arp -Ds 192.168.1.100 eth1
>> > > e) arp -Ds 192.168.1.200 eth1
>> > > f) sysctl -w net.ipv4.ip_nonlocal_bind=1
>> > > g) sysctl -w net.ipv4.conf.all.accept_local=1
>> > > # Assuming that the machine has 8 cores
>> > > h) taskset 000f netserver -L 192.168.1.200
>> > > i) taskset 00f0 netperf -t TCP_CRR -L 192.168.1.100 -H 192.168.1.200 -l 30
>> > >
>> > > Signed-off-by: Mahesh Bandewar <maheshb@google.com>
>> > > Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
>> >
>> > Since this is a boolean it SHOULD go into ethtool_flags rather than
>> > being a high level operation.
>>
>> It could do, but I though ETHTOOL_{G,S}FLAGS were intended for
>> controlling offload features.
>
> It just seems the number of hooks keeps growing which takes more space
> and increases complexity.
>
> There was some talk about changing GRO/TSO/UFO .. to be bits in FLAGS
> but not sure how far along that is.
> --
>
This is not merely getting / setting flags but involves invoking a
method from the driver(s). If done this way; the code in
ethtool_op_set_flags() will have to be special-cased to handle this
flag which (I think) would not be clean.
next prev parent reply other threads:[~2011-01-05 1:39 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-30 8:00 [PATCH] Net-ethtool : Allow ethtool to set interface in loopback mode Mahesh Bandewar
2010-11-30 9:48 ` Simon Horman
2010-11-30 15:01 ` Ben Hutchings
2010-11-30 19:05 ` Mahesh Bandewar
2010-11-30 19:15 ` Ben Hutchings
2010-11-30 21:22 ` Mahesh Bandewar
2010-11-30 23:57 ` [PATCH v2] " Mahesh Bandewar
2010-12-01 14:54 ` Ben Hutchings
2010-12-01 20:14 ` [PATCH v3] " Mahesh Bandewar
2010-12-01 20:17 ` Ben Hutchings
2010-12-10 4:11 ` David Miller
2011-01-05 0:30 ` [PATCH v2] net: " Mahesh Bandewar
2011-01-05 0:36 ` Stephen Hemminger
2011-01-05 1:21 ` Ben Hutchings
2011-01-05 1:29 ` Stephen Hemminger
2011-01-05 1:34 ` Rick Jones
2011-01-05 1:53 ` Stephen Hemminger
2011-01-05 1:59 ` Ben Hutchings
2011-01-05 2:06 ` Mahesh Bandewar
2011-01-05 1:39 ` Mahesh Bandewar [this message]
2011-01-05 16:22 ` Jeff Garzik
2011-01-06 22:13 ` Ben Hutchings
2011-01-07 0:47 ` Mahesh Bandewar
2011-01-07 1:30 ` Ben Hutchings
2011-01-12 19:24 ` Mahesh Bandewar
2011-01-22 0:23 ` [PATCH v4] net-next-2.6: " Mahesh Bandewar
2011-01-23 2:35 ` Ben Hutchings
2011-01-23 17:12 ` Mahesh Bandewar
2011-01-23 17:32 ` Michał Mirosław
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