From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pankaj Gupta Subject: Re: [PATCH v2 net-next] bridge: Add ability to enable TSO Date: Fri, 9 Jan 2015 14:10:13 -0500 (EST) Message-ID: <1077735415.7059200.1420830613699.JavaMail.zimbra@redhat.com> References: <1420780600-11313-1-git-send-email-makita.toshiaki@lab.ntt.co.jp> <1138400428.6686751.1420782286490.JavaMail.zimbra@redhat.com> <54AF73AD.4000008@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "David S . Miller" , Stephen Hemminger , netdev@vger.kernel.org, bridge@lists.linux-foundation.org To: Toshiaki Makita Return-path: Received: from mx6-phx2.redhat.com ([209.132.183.39]:42276 "EHLO mx6-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752515AbbAITKT (ORCPT ); Fri, 9 Jan 2015 14:10:19 -0500 In-Reply-To: <54AF73AD.4000008@lab.ntt.co.jp> Sender: netdev-owner@vger.kernel.org List-ID: > > > >> > >> Currently a bridge device turns off TSO feature if no bridge ports > >> support it. We can always enable it, since packets can be segmented on > >> ports by software as well as on the bridge device. > >> This will reduce the number of packets processed in the bridge. > >> > >> Signed-off-by: Toshiaki Makita > >> --- > >> v2: Use an existing helper function. > >> > >> net/bridge/br_if.c | 1 + > >> 1 file changed, 1 insertion(+) > >> > >> diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c > >> index ed307db..81e49fb 100644 > >> --- a/net/bridge/br_if.c > >> +++ b/net/bridge/br_if.c > >> @@ -424,6 +424,7 @@ netdev_features_t br_features_recompute(struct > >> net_bridge > >> *br, > >> features = netdev_increment_features(features, > >> p->dev->features, mask); > >> } > >> + features = netdev_add_tso_features(features, mask); > > > > Just a doubt. Are we inducing latency if source has traffic at very low > > rate. > > I mean by default do we need it? > > Is your concern tcp_tso_should_defer() in tcp_write_xmit()? yes. > If so, since TSO packet is created by GSO even without this patch, this > should not increase latency there. > This patch just delays the point of software segmentation from the > bridge device to its port. I think now I got your point. Thanks, Pankaj > > Thanks, > Toshiaki Makita > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >