From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Subject: Re: [PATCH bpf-next v3 01/15] net: initial AF_XDP skeleton
Date: Thu, 24 May 2018 10:57:30 -0700
Message-ID: <20180524175728.nj3eezutj5qbpfo2@ast-mbp.dhcp.thefacebook.com>
References: <20180502110136.3738-1-bjorn.topel@gmail.com>
 <20180502110136.3738-2-bjorn.topel@gmail.com>
 <20180523155047.6c136279@xeon-e3>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@gmail.com>,
        magnus.karlsson@intel.com, alexander.h.duyck@intel.com,
        alexander.duyck@gmail.com, john.fastabend@gmail.com, ast@fb.com,
        brouer@redhat.com, willemdebruijn.kernel@gmail.com,
        daniel@iogearbox.net, mst@redhat.com, netdev@vger.kernel.org,
        =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@intel.com>,
        michael.lundkvist@ericsson.com, jesse.brandeburg@intel.com,
        anjali.singhai@intel.com, qi.z.zhang@intel.com
To: Stephen Hemminger <stephen@networkplumber.org>
Return-path: <netdev-owner@vger.kernel.org>
Received: from mail-pf0-f194.google.com ([209.85.192.194]:43438 "EHLO
        mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1030352AbeEXR5f (ORCPT
        <rfc822;netdev@vger.kernel.org>); Thu, 24 May 2018 13:57:35 -0400
Received: by mail-pf0-f194.google.com with SMTP id j20-v6so1255082pff.10
        for <netdev@vger.kernel.org>; Thu, 24 May 2018 10:57:34 -0700 (PDT)
Content-Disposition: inline
In-Reply-To: <20180523155047.6c136279@xeon-e3>
Sender: netdev-owner@vger.kernel.org
List-ID: <netdev.vger.kernel.org>

On Wed, May 23, 2018 at 03:50:47PM -0700, Stephen Hemminger wrote:
> Most distributions will want it to be a module so that it is not loaded
> unless used, and AF_XDP could be also be disabled by blacklisting the module.

I think the opposite will be the case. Anyone who cares about performance
would want AF_XDP code to be builtin, since builtin vs module gives additional
performance. All our NIC drivers are builtin, since we see noticeable
perf gains on production workloads.
Hence I'd rather see us spending time on improving AF_XDP instead
of making it a module and forever struggling with maintaining it as a module.

More so I think it's time to get rid of IPV6=m for good. The kernel
is full of ugly hacks and performance degradation due to indirect calls
just because IPV6=m is still supported.
Folks that care about vmlinux size should be using kconfig to compile it out.