From patchwork Wed Aug 17 19:34:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Fastabend X-Patchwork-Id: 660229 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3sDzvd36bXz9t2F for ; Thu, 18 Aug 2016 05:34:53 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=bwVu8EKO; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753183AbcHQTer (ORCPT ); Wed, 17 Aug 2016 15:34:47 -0400 Received: from mail-oi0-f67.google.com ([209.85.218.67]:34080 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752915AbcHQTep (ORCPT ); Wed, 17 Aug 2016 15:34:45 -0400 Received: by mail-oi0-f67.google.com with SMTP id t127so12986370oie.1 for ; Wed, 17 Aug 2016 12:34:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:subject:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=p/Fq03M/Wn339BVB7hUDEF9PxzbXyJaiI2E/5dCUMWo=; b=bwVu8EKOJ8y1avMOiiq4H9dqWnhDDobVYeDSp6MZaCI2LOQMj/ds1OBczlPFA3EOsz bw6dtIuuks4n8UqTQs0z95NIf+EJCTBMXiPKXYUsY0HKV+1/12ih04+uGvjaPM7oRvro AZ9fDV7xb3l6k/qg/i2GopCPOp6/rFG9mt4PpE0ciZn7mzxZUv+yP5O/EMLTBbgYyHYV SzXrOTxY+KkapLfIW2YwZfAyi5gfIp909iI+jPwudaYl2P7aAPofuowHcCp2pnfyu/sc l3HMKmyIfqf8BzVpQ5WoPprHcf5OOoZ8iGJVxGeuOEIrp5AwyehTwNeF+8hrB69ql58W qKmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:subject:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=p/Fq03M/Wn339BVB7hUDEF9PxzbXyJaiI2E/5dCUMWo=; b=SsCJKXyEj4NZwa+RPEZCkccx6KuvkIHCeFYiLxB62frHzz5tWshinJugnrOuNxO00L CgiJg5yy6PqjRZlOxbou40hLYveifsDplI6W74eyfJHlNx0lQGQh7knwcxo6fbiQizYD 1Qq31hLgnY3bopoEV1GCV3mExdGNdQfqJAKqd2aQ2ZkLDT9LLm+dRiN4MoRbIwYvQf6F R6m1I/n9jM3G6ayyYkWePAFjdh+TWGumyKgddmSrbY9DrsdBH1hBlYFUSO60oSOi0WqA arfUMU1ZV0w5rgu6wVprPTmVtZwj4kuYNHGWc+w1Sq/wIJSBHwx79s/F0toDctTF+CS6 99/g== X-Gm-Message-State: AEkooutC3IZ9wE6KSGecT8L0pBDUM7rgpoz3W8NvV/kvxBbU8oggIL/22Lt6sxc+H1Go3Q== X-Received: by 10.202.49.201 with SMTP id x192mr23878121oix.66.1471462473126; Wed, 17 Aug 2016 12:34:33 -0700 (PDT) Received: from [127.0.1.1] ([72.168.145.64]) by smtp.gmail.com with ESMTPSA id v1sm484039otf.18.2016.08.17.12.34.23 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 17 Aug 2016 12:34:32 -0700 (PDT) From: John Fastabend X-Google-Original-From: John Fastabend Subject: [RFC PATCH 02/13] net: sched: qdisc_qlen for per cpu logic To: xiyou.wangcong@gmail.com, jhs@mojatatu.com, alexei.starovoitov@gmail.com, eric.dumazet@gmail.com, brouer@redhat.com Cc: john.r.fastabend@intel.com, netdev@vger.kernel.org, john.fastabend@gmail.com, davem@davemloft.net Date: Wed, 17 Aug 2016 12:34:16 -0700 Message-ID: <20160817193416.27032.62729.stgit@john-Precision-Tower-5810> In-Reply-To: <20160817193120.27032.20918.stgit@john-Precision-Tower-5810> References: <20160817193120.27032.20918.stgit@john-Precision-Tower-5810> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This is a bit interesting because it means sch_direct_xmit will return a positive value which causes the dequeue/xmit cycle to continue only when a specific cpu has a qlen > 0. However checking each cpu for qlen will break performance so its important to note that qdiscs that set the no lock bit need to have some sort of per cpu enqueue/dequeue data structure that maps to the per cpu qlen value. Signed-off-by: John Fastabend --- include/net/sch_generic.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 3de6a8c..354951d 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -247,8 +247,16 @@ static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) BUILD_BUG_ON(sizeof(qcb->data) < sz); } +static inline int qdisc_qlen_cpu(const struct Qdisc *q) +{ + return this_cpu_ptr(q->cpu_qstats)->qlen; +} + static inline int qdisc_qlen(const struct Qdisc *q) { + if (q->flags & TCQ_F_NOLOCK) + return qdisc_qlen_cpu(q); + return q->q.qlen; }