From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750999AbdE3P3q (ORCPT ); Tue, 30 May 2017 11:29:46 -0400 Received: from vps0.lunn.ch ([178.209.37.122]:58337 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750871AbdE3P3p (ORCPT ); Tue, 30 May 2017 11:29:45 -0400 Date: Tue, 30 May 2017 17:29:43 +0200 From: Andrew Lunn To: Vivien Didelot Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@savoirfairelinux.com, "David S. Miller" , Florian Fainelli Subject: Re: [PATCH net-next 6/7] net: dsa: remove useless copy of tagger xmit Message-ID: <20170530152943.GH22758@lunn.ch> References: <20170530142131.23568-1-vivien.didelot@savoirfairelinux.com> <20170530142131.23568-7-vivien.didelot@savoirfairelinux.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170530142131.23568-7-vivien.didelot@savoirfairelinux.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 30, 2017 at 10:21:30AM -0400, Vivien Didelot wrote: > The dsa_slave_priv structure holds a copy of the dsa_device_ops xmit > function. It is always assigned to the switch tree xmit function. > > Remove this useless copy. > > Signed-off-by: Vivien Didelot > --- > net/dsa/dsa_priv.h | 3 --- > net/dsa/slave.c | 4 +--- > 2 files changed, 1 insertion(+), 6 deletions(-) > > diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h > index 0fdd2a8a4ad8..282a55639285 100644 > --- a/net/dsa/dsa_priv.h > +++ b/net/dsa/dsa_priv.h > @@ -71,9 +71,6 @@ struct dsa_device_ops { > }; > > struct dsa_slave_priv { > - struct sk_buff * (*xmit)(struct sk_buff *skb, > - struct net_device *dev); > - > /* DSA port data, such as switch, port index, etc. */ > struct dsa_port *dp; > > diff --git a/net/dsa/slave.c b/net/dsa/slave.c > index 887e26695519..ebad2af4d3a8 100644 > --- a/net/dsa/slave.c > +++ b/net/dsa/slave.c > @@ -363,7 +363,7 @@ static netdev_tx_t dsa_slave_xmit(struct sk_buff *skb, struct net_device *dev) > dev->stats.tx_bytes += skb->len; > > /* Transmit function may have to reallocate the original SKB */ > - nskb = p->xmit(skb, dev); > + nskb = p->dp->ds->dst->tag_ops->xmit(skb, dev); This is also the hot path for DSA transmit. Do we really want to do 4 extra pointer dereferences a million times per second, compared to one copy during setup? Andrew