From: Hannes Frederic Sowa <hannes@stressinduktion.org>
Subject: Re: [RFC PATCH 1/2] netpoll:  Remove dead netpoll_rx code
Date: Tue, 11 Mar 2014 16:34:03 +0100
Message-ID: <20140311153403.GC29404@order.stressinduktion.org>
References: <871ty9qvaf.fsf_-_@xmission.com> <87vbvlpgnk.fsf_-_@xmission.com> <1394509467.21721.2.camel@edumazet-glaptop2.roam.corp.google.com> <20140311.004217.1616529960369263682.davem@davemloft.net> <1394514158.21721.7.camel@edumazet-glaptop2.roam.corp.google.com> <87a9cxf7mp.fsf_-_@xmission.com> <8738ipf7kn.fsf_-_@xmission.com> <1394540961.21721.22.camel@edumazet-glaptop2.roam.corp.google.com> <20140311082312.5ad00119@nehalam.linuxnetplumber.net>
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Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	David Miller <davem@davemloft.net>, netdev@vger.kernel.org,
	xiyou.wangcong@gmail.com, mpm@selenic.com, satyam.sharma@gmail.com
To: Stephen Hemminger <stephen@networkplumber.org>
Content-Disposition: inline
In-Reply-To: <20140311082312.5ad00119@nehalam.linuxnetplumber.net>
Sender: netdev-owner@vger.kernel.org

On Tue, Mar 11, 2014 at 08:23:12AM -0700, Stephen Hemminger wrote:
> On Tue, 11 Mar 2014 05:29:21 -0700
> Eric Dumazet <eric.dumazet@gmail.com> wrote:
> 
> > On Tue, 2014-03-11 at 01:44 -0700, Eric W. Biederman wrote:
> > > The netpoll_rx code only becomes active if the netpoll rx_skb_hook is
> > > implemented.  There is not a single implementation of the netpoll
> > > rx_skb_hook in the kernel.
> > > 
> > > There are problems with the netpoll packet receive code. Most
> > > speifically every packet that makes it to netpoll_neigh_reply is
> > > leaked.
> > > 
> > > Given that the netpoll packet receive code is buggy and has not been used
> > > for a decade let's just remove it.
> > > 
> > > Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
> > > ---
> > >  drivers/net/Kconfig       |    5 -
> > >  include/linux/netdevice.h |   17 --
> > >  include/linux/netpoll.h   |   59 ------
> > >  net/core/dev.c            |   11 +-
> > >  net/core/netpoll.c        |  471 ---------------------------------------------
> > >  5 files changed, 1 insertions(+), 562 deletions(-)
> > 
> > I cannot agree more, thanks Eric.
> > 
> > Acked-by: Eric Dumazet <edumazet@google.com>
> 
> I agree but removing it breaks people trying to kgdb over network (kgdboe).
> That code never made it upstream, was unreliable and fragile and should be
> sent to the retirement home with IMQ.

:)

But there is still no replacement for IMQ if one wants to do ingress NAT-aware
traffic shaping, not even with ifb, I fear? So to be fair there still seems to
be a reason why IMQ is still around.

But that is a different topic...