Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755414AbcDNOvn (ORCPT ); Thu, 14 Apr 2016 10:51:43 -0400 Received: from mx2.suse.de ([195.135.220.15]:43761 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754131AbcDNOvm (ORCPT ); Thu, 14 Apr 2016 10:51:42 -0400 Date: Thu, 14 Apr 2016 16:51:38 +0200 (CEST) From: Jiri Kosina X-X-Sender: jkosina@pobox.suse.cz To: Jamal Hadi Salim cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Deleting child qdisc doesn't reset parent to default qdisc? In-Reply-To: Message-ID: References: User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1410 Lines: 43 On Thu, 14 Apr 2016, Jiri Kosina wrote: > In a nutshell, is this expected behavior or bug? Just to clarify what seems to suggest to me that this is rather a bug that needs to be fixed (but apparently one that has been there for quite a long time) can be demonstrated by this: > > ===== > jikos:~ # tc qdisc show > qdisc tbf 10: dev eth0 root refcnt 2 rate 800Mbit burst 131000b lat 1.0ms The above configuration works. > jikos:~ # ping -c 1 nix.cz | head -2 > PING nix.cz (195.47.235.3) 56(84) bytes of data. > 64 bytes from info.nix.cz (195.47.235.3): icmp_seq=1 ttl=89 time=1.59 ms > > jikos:~ # tc qdisc add dev eth0 parent 10:1 sfq > jikos:~ # tc qdisc show > qdisc tbf 10: dev eth0 root refcnt 2 rate 800Mbit burst 131000b lat 1.0ms > qdisc sfq 8008: dev eth0 parent 10:1 limit 127p quantum 1514b depth 127 divisor 1024 > > jikos:~ # ping -c 1 nix.cz | head -2 > PING nix.cz (195.47.235.3) 56(84) bytes of data. > 64 bytes from info.nix.cz (195.47.235.3): icmp_seq=1 ttl=89 time=1.67 ms > > jikos:~ # tc qdisc del dev eth0 parent 10:1 sfq > jikos:~ # tc qdisc show > qdisc tbf 10: dev eth0 root refcnt 2 rate 800Mbit burst 131000b lat 1.0ms The above configuration doesn't although it's identical to the working one at the beginning. > jikos:~ # ping -c 1 nix.cz | head -2 > PING nix.cz (195.47.235.3) 56(84) bytes of data. > [ ... nothing happens ... ] > ^C -- Jiri Kosina SUSE Labs