From patchwork Mon Jan 7 19:47:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 1021557 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=toke.dk Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=toke.dk header.i=@toke.dk header.b="FMbLy2tR"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43YQsv1Jcjz9rxp for ; Tue, 8 Jan 2019 06:48:03 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727627AbfAGTsB (ORCPT ); Mon, 7 Jan 2019 14:48:01 -0500 Received: from mail.toke.dk ([52.28.52.200]:35815 "EHLO mail.toke.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726654AbfAGTsB (ORCPT ); Mon, 7 Jan 2019 14:48:01 -0500 From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1546890479; bh=dwWAS4whMeSX6i6NqBvBnY/2nAbWuvrWaFkFkfi8iwY=; h=From:To:Cc:Subject:Date:From; b=FMbLy2tRm4fXK1EzHMreQ51i9AIZwyxo/yvWtnDxNxPczT7OsckWIN2H3T/5LQmIZ mAHy5FHTmV+j2cz77d83qXYPFSjAAU0YX9zvnZG+F7h2VgCQ5Hhw0LenB9U/g6BaX7 lI2Nq6OaF3Lbq1UF9kClYWfYjfkn+sw1VTOneHQVAa3Ex9iKzb6aUpr2/z3lcGnQwY rKOLeGd9euuexXjR6oNA2PdHLQlE2hW+lzmlNOa7IzcymNKz5Od6k3fnIurmKc8BSr mkM8h9bRwn36KJ90lvY4u22mmlDFrQCI43v5mqe8pXVyBcpa0K8qDMTIocQT2Th+/Q 18Aoh3E6fbGjw== To: netdev@vger.kernel.org Cc: cake@lists.bufferbloat.net, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Subject: [PATCH 0/4] sched: Fix qdisc interactions exposed by using sch_cake as a leaf qdisc Date: Mon, 7 Jan 2019 20:47:29 +0100 Message-Id: <20190107194733.31138-1-toke@toke.dk> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This series fixes a couple of issues exposed by running sch_cake as a leaf qdisc in an HFSC tree, which were discovered and reported by Pete Heist. The interaction between CAKE's GSO splitting and the parent qdisc's notion of its own queue length could cause queue stalls. While investigating the report, I also noticed that several qdiscs would dereference the skb pointer after dequeue, which is potentially problematic since the GSO splitting code also frees the original skb. See the individual patches in the series for details. Toke Høiland-Jørgensen (4): sched: Avoid dereferencing skb pointer after child enqueue sched: Fix detection of empty queues in child qdiscs sch_api: Allow reducing queue backlog by a negative value sch_cake: Correctly update parent qlen when splitting GSO packets include/net/sch_generic.h | 3 +-- net/sched/sch_api.c | 3 +-- net/sched/sch_cake.c | 5 +++-- net/sched/sch_cbs.c | 3 ++- net/sched/sch_drr.c | 7 +++++-- net/sched/sch_dsmark.c | 3 ++- net/sched/sch_hfsc.c | 9 +++++---- net/sched/sch_htb.c | 3 ++- net/sched/sch_prio.c | 3 ++- net/sched/sch_qfq.c | 20 ++++++++++++-------- net/sched/sch_tbf.c | 3 ++- 11 files changed, 37 insertions(+), 25 deletions(-)