From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: regression caused by 1d2024f61ec14bdb0c57a97a3fe73685abc2d198? Date: Wed, 6 Feb 2013 19:42:28 +0200 Message-ID: <20130206174228.GA16991@redhat.com> References: <20130206114321.GA13497@redhat.com> <1360156059.28557.28.camel@edumazet-glaptop> <20130206155049.GB14735@redhat.com> <1360167332.28557.36.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: alexander.h.duyck@intel.com, stephen.s.ko@intel.com, jeffrey.t.kirsher@intel.com, David Miller , netdev@vger.kernel.org, sony.chacko@qlogic.com, mchan@broadcom.com, jitendra.kalsaria@qlogic.com, eilong@broadcom.com To: Eric Dumazet Return-path: Received: from mx1.redhat.com ([209.132.183.28]:41713 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755156Ab3BFRiQ (ORCPT ); Wed, 6 Feb 2013 12:38:16 -0500 Content-Disposition: inline In-Reply-To: <1360167332.28557.36.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Feb 06, 2013 at 08:15:32AM -0800, Eric Dumazet wrote: > On Wed, 2013-02-06 at 17:50 +0200, Michael S. Tsirkin wrote: > > > Also, I'm not sure I understand when should drivers set gso size > > for incoming messages and what is a reasonable value. > > Commit log talks about improved performance for lossy connections, > > in this case, isn't this something net core should set? > > > > I see 3 in-tree drivers that do this: > > > > drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c: skb_shinfo(skb)->gso_size = bnx2x > > bnx2x is fine, take a look at lines 464 Is this what you mean? /* This is needed in order to enable forwarding support */ if (frag_size) { skb_shinfo(skb)->gso_size = bnx2x_set_lro_mss(bp, tpa_info->parsing_flags, len_on_bd); /* set for GRO */ if (fp->mode == TPA_MODE_GRO) skb_shinfo(skb)->gso_type = (GET_FLAG(tpa_info->parsing_flags, PARSING_FLAGS_OVER_ETHERNET_PROTOCOL) == PRS_FLAG_OVERETH_IPV6) ? SKB_GSO_TCPV6 : SKB_GSO_TCPV4; } I see it sets gso_type but apparently only if mode is GRO? Will this still break if mode is set to LRO? > > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c: skb_shinfo(skb)->gso_size = DIV_ROUND_UP((skb->le > > drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c: skb_shinfo(skb)->gso_size = qlcnic_get_lr > > > > It seems likely the same issue applies there? > > Yes