From patchwork Mon Jan 6 23:20:19 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Poirier X-Patchwork-Id: 307474 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 DD00F2C00B8 for ; Tue, 7 Jan 2014 10:20:58 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933718AbaAFXUi (ORCPT ); Mon, 6 Jan 2014 18:20:38 -0500 Received: from mail-qc0-f178.google.com ([209.85.216.178]:45052 "EHLO mail-qc0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932962AbaAFXUh (ORCPT ); Mon, 6 Jan 2014 18:20:37 -0500 Received: by mail-qc0-f178.google.com with SMTP id i17so18257579qcy.23 for ; Mon, 06 Jan 2014 15:20:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=gU7NzS9wcX2Wst1wyE/0MKWtSEdXhzTxQIXReMkifDM=; b=y3gIY7RQul3s8T5Xk8mbW0/n6QDBWBqe+TOt9Vk+r2udhyJPHdUVIkd2j9QCsYjF2X JN0CnOfnrX5RxnDyBlHf63PwORd9j4ohjGn+4YfbPwqW9ddig2BuQl3QO8s9hSUOe8YN ZONsx9fnkwJ6nxQT2PM2dxGbBB80oV4kopKQHswLRdAb7Yn6c87zcvLDGX2JEf6gOTOK bTQJiyxbQCUi14e8i+bly1oeZKPm5cDz9U/3yt/HBsKl6RZJ7H1HkfB98Q5uYzzyL6su NPD5VMcU/XGh/gDHbuu8p1h9hxA/7XxooQA/3TW4/06QK3hQlmucIdQfiEFYWrNiRg1P qWGA== X-Received: by 10.49.12.102 with SMTP id x6mr191679283qeb.5.1389050436629; Mon, 06 Jan 2014 15:20:36 -0800 (PST) Received: from d2.synalogic.ca ([206.180.243.138]) by mx.google.com with ESMTPSA id c6sm97326851qev.15.2014.01.06.15.20.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Jan 2014 15:20:36 -0800 (PST) From: Benjamin Poirier To: "David S. Miller" Cc: Eric Dumazet , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Tom Herbert Subject: [PATCH] net: Do not enable tx-nocache-copy by default Date: Mon, 6 Jan 2014 18:20:19 -0500 Message-Id: <1389050419-9060-1-git-send-email-bpoirier@suse.de> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1389041855.12212.210.camel@edumazet-glaptop2.roam.corp.google.com> References: <1389041855.12212.210.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org There are many cases where this feature does not improve performance or even reduces it. See the following discussion for example perf numbers: http://thread.gmane.org/gmane.linux.network/298345 CC: Tom Herbert Signed-off-by: Benjamin Poirier --- net/core/dev.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 153ee2f..2e242583 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5783,13 +5783,8 @@ int register_netdevice(struct net_device *dev) dev->features |= NETIF_F_SOFT_FEATURES; dev->wanted_features = dev->features & dev->hw_features; - /* Turn on no cache copy if HW is doing checksum */ if (!(dev->flags & IFF_LOOPBACK)) { dev->hw_features |= NETIF_F_NOCACHE_COPY; - if (dev->features & NETIF_F_ALL_CSUM) { - dev->wanted_features |= NETIF_F_NOCACHE_COPY; - dev->features |= NETIF_F_NOCACHE_COPY; - } } /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.