From patchwork Tue May 15 14:24:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 913664 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=fail (p=none dis=none) header.from=redhat.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40lfwd35N1z9ryk for ; Wed, 16 May 2018 00:25:05 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753372AbeEOOZC (ORCPT ); Tue, 15 May 2018 10:25:02 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58976 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752491AbeEOOZB (ORCPT ); Tue, 15 May 2018 10:25:01 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4D472401608A; Tue, 15 May 2018 14:25:01 +0000 (UTC) Received: from dhcppc0.redhat.com (ovpn-117-200.ams2.redhat.com [10.36.117.200]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5AB2E2017D0D; Tue, 15 May 2018 14:24:59 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: "David S. Miller" , Jamal Hadi Salim , Cong Wang , Jiri Pirko , John Fastabend , "Michael S. Tsirkin" Subject: [PATCH net-next 0/2] sched: refactor NOLOCK qdiscs Date: Tue, 15 May 2018 16:24:35 +0200 Message-Id: X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Tue, 15 May 2018 14:25:01 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Tue, 15 May 2018 14:25:01 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'pabeni@redhat.com' RCPT:'' Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org With the introduction of NOLOCK qdiscs, pfifo_fast performances in the uncontended scenario degraded measurably, especially after the commit eb82a9944792 ("net: sched, fix OOO packets with pfifo_fast"). This series restore the pfifo_fast performances in such scenario back the previous level, mainly reducing the number of atomic operations required to perform the qdisc_run() call. Even performances in the contended scenario increase measurably. Note: This series is on top of: sched: manipulate __QDISC_STATE_RUNNING in qdisc_run_* helpers Paolo Abeni (2): sched: replace __QDISC_STATE_RUNNING bit with a spin lock pfifo_fast: drop unneeded additional lock on dequeue include/linux/skb_array.h | 5 +++++ include/net/sch_generic.h | 10 +++++----- net/sched/sch_generic.c | 15 +++++++++++++-- 3 files changed, 23 insertions(+), 7 deletions(-)