From patchwork Fri Dec 27 01:42:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Oltean X-Patchwork-Id: 1215615 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) 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=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="F4c6pMYX"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47kV1q5BdWz9sPh for ; Fri, 27 Dec 2019 12:42:23 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727152AbfL0BmW (ORCPT ); Thu, 26 Dec 2019 20:42:22 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:50504 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726375AbfL0BmU (ORCPT ); Thu, 26 Dec 2019 20:42:20 -0500 Received: by mail-wm1-f68.google.com with SMTP id a5so7038532wmb.0; Thu, 26 Dec 2019 17:42:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=jOrvQNI+LQ4nQP6ABrg57U7Wq2Xttks3TXMfcHTK/GE=; b=F4c6pMYXNDzA1s/dwsTHXlnzSZpcdo07x/PwPjAhX8ZrPu4O9RrLCxUnwx1dnVB5Q8 rqdfN8/mAnolPuIx1Fk2cykuFE6l/HXqYcYtgSMSvwwScb6lFHeh9L6YesdAxxhCXuDo i2Wcmypv6u+lWXyEeCgo7U3kXBF0nQCXL+mtQJwhHAb9SNPb2Uq0z01ho10VqIMpqIFl DhR///zWiwoScMcjf8IJ49la211Ebe7stGtZ1OOAL6dlIexwB3sYn10871/kPQ7T73Q2 lzdGtqbopavPzzRuc2Y0ngO8KUPQXPgb7jK5REzjqWHlbN8XnxSj/fn7W7M0jxXRBKI/ u2SA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=jOrvQNI+LQ4nQP6ABrg57U7Wq2Xttks3TXMfcHTK/GE=; b=mH5DbWZ0XJeEOmzdEe9OwroiKpxI7nnXk7O6Wot7rJbIm9pr+ECHglbbHy4PlV06Lj C0ajzH1WldqQsHNID6fGpj1EffSsD7uf64K6qozFCETKA1ocN67rfFK66o/9sM5TXVx9 po7K8cuG4+bbXx+IUM7TEXTXs90b1GR222tJdG/9PqJwcaIiZo/mDRd7OGFGr53tM16P B3NCh2azGAEPchAPou+ZYzu359D3gd4koq3NCNMnUyethxpp50USPJnpqzuI7Kv/ErRk gd71jpyO67pzHOd/1i2vfILJP++3AFHObHz720AafPaM/ohNCcSYdNTzQv8buB/rrAIk wQPg== X-Gm-Message-State: APjAAAUqt2EredczWQDc7RRBgGi0eiXAwW/2FuSLM/ELGRvbV/z3Qblj TuVKvbM64SuXxLvcfd1jWJo= X-Google-Smtp-Source: APXvYqyq2Fa+h9Dmoua7/5yJGo/bgiv2N1pLxPfvoMOxOg9YjQlT2pSAeL+m5qOYQvdePQVbEHQX7g== X-Received: by 2002:a05:600c:a:: with SMTP id g10mr17045672wmc.14.1577410938124; Thu, 26 Dec 2019 17:42:18 -0800 (PST) Received: from localhost.localdomain ([188.25.254.226]) by smtp.gmail.com with ESMTPSA id q11sm32622130wrp.24.2019.12.26.17.42.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Dec 2019 17:42:17 -0800 (PST) From: Vladimir Oltean To: f.fainelli@gmail.com, vivien.didelot@gmail.com, andrew@lunn.ch, davem@davemloft.net Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Vladimir Oltean Subject: [PATCH net-next 1/2] net: dsa: Remove deferred_xmit from dsa_skb_cb Date: Fri, 27 Dec 2019 03:42:07 +0200 Message-Id: <20191227014208.7189-2-olteanv@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191227014208.7189-1-olteanv@gmail.com> References: <20191227014208.7189-1-olteanv@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The introduction of the deferred xmit mechanism in DSA has made the hotpath slightly more inefficient for everybody, since DSA_SKB_CB(skb)->deferred_xmit needed to be initialized to false for every transmitted frame, in order to figure out whether the driver requested deferral or not. That was necessary to avoid kfree_skb from freeing the skb. But actually we can just remove that variable in the skb->cb and counteract the effect of kfree_skb with skb_get, much to the same effect. The advantage, of course, being that anybody who doesn't use deferred xmit doesn't need to do any extra operation in the hotpath. Signed-off-by: Vladimir Oltean --- include/net/dsa.h | 1 - net/dsa/slave.c | 12 ++++++------ 2 files changed, 6 insertions(+), 7 deletions(-) diff --git a/include/net/dsa.h b/include/net/dsa.h index 6767dc3f66c0..5d510a4da5d0 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -88,7 +88,6 @@ struct dsa_device_ops { struct dsa_skb_cb { struct sk_buff *clone; - bool deferred_xmit; }; struct __dsa_skb_cb { diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 78ffc87dc25e..9f7e47dcdc20 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -518,7 +518,6 @@ static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev) s->tx_bytes += skb->len; u64_stats_update_end(&s->syncp); - DSA_SKB_CB(skb)->deferred_xmit = false; DSA_SKB_CB(skb)->clone = NULL; /* Identify PTP protocol packets, clone them, and pass them to the @@ -531,8 +530,7 @@ static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev) */ nskb = p->xmit(skb, dev); if (!nskb) { - if (!DSA_SKB_CB(skb)->deferred_xmit) - kfree_skb(skb); + kfree_skb(skb); return NETDEV_TX_OK; } @@ -543,10 +541,12 @@ void *dsa_defer_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_port *dp = dsa_slave_to_port(dev); - DSA_SKB_CB(skb)->deferred_xmit = true; - - skb_queue_tail(&dp->xmit_queue, skb); + /* Increase refcount so the kfree_skb in dsa_slave_xmit + * won't really free the packet. + */ + skb_queue_tail(&dp->xmit_queue, skb_get(skb)); schedule_work(&dp->xmit_work); + return NULL; } EXPORT_SYMBOL_GPL(dsa_defer_xmit);