From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751655AbdCHO5j (ORCPT ); Wed, 8 Mar 2017 09:57:39 -0500 Received: from mail-wr0-f193.google.com ([209.85.128.193]:36376 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750734AbdCHO5i (ORCPT ); Wed, 8 Mar 2017 09:57:38 -0500 Date: Wed, 8 Mar 2017 15:57:33 +0100 From: Jiri Pirko To: Jiri Kosina Cc: "David S. Miller" , Stephen Hemminger , Eric Dumazet , Jamal Hadi Salim , Phil Sutter , Cong Wang , Daniel Borkmann , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] net: sched: make default fifo qdiscs appear in the dump Message-ID: <20170308145733.GL1919@nanopsycho> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Wed, Mar 08, 2017 at 01:03:42PM CET, jikos@kernel.org wrote: >From: Jiri Kosina > >The original reason [1] for having hidden qdiscs (potential scalability >issues in qdisc_match_from_root() with single linked list in case of large >amount of qdiscs) has been invalidated by 59cc1f61f0 ("net: sched: convert >qdisc linked list to hashtable"). > >This allows us for bringing more clarity and determinism into the dump by >making default pfifo qdiscs visible. > >We're not turning this on by default though, at it was deemed [2] too >intrusive / unnecessary change of default behavior towards userspace. >Instead, TCA_DUMP_INVISIBLE netlink attribute is introduced, which allows >applications to request complete qdisc hierarchy dump, including the >ones that have always been implicit/invisible. > >Singleton noop_qdisc stays invisible, as teaching the whole infrastructure >about singletons would require quite some surgery with very little gain >(seeing no qdisc or seeing noop qdisc in the dump is probably setting >the same user expectation). > >[1] http://lkml.kernel.org/r/1460732328.10638.74.camel@edumazet-glaptop3.roam.corp.google.com >[2] http://lkml.kernel.org/r/20161021.105935.1907696543877061916.davem@davemloft.net > >Signed-off-by: Jiri Kosina >--- [...] >diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h >index 262f0379d83a..c7de00e09797 100644 >--- a/include/uapi/linux/rtnetlink.h >+++ b/include/uapi/linux/rtnetlink.h >@@ -542,6 +542,7 @@ enum { > TCA_FCNT, > TCA_STATS2, > TCA_STAB, >+ TCA_DUMP_INVISIBLE, > TCA_PAD, You are changing UAPI value of TCA_PAD... > __TCA_MAX > };