From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: bad TSO performance in 2.6.9-rc2-BK Date: Thu, 23 Sep 2004 00:06:28 +0200 Sender: netdev-bounce@oss.sgi.com Message-ID: <20040922220628.GC2619@wotan.suse.de> References: <20040920063012.GL2825@krispykreme> <20040920203021.GD4242@wotan.suse.de> <20040921155835.18aee381.davem@davemloft.net> <20040922140000.GD27432@wotan.suse.de> <20040922111209.7887df53.davem@davemloft.net> <20040922195515.GA2619@wotan.suse.de> <20040922133906.7d57ef49.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Grover , ak@suse.de, anton@samba.org, netdev@oss.sgi.com Return-path: To: "David S. Miller" Content-Disposition: inline In-Reply-To: <20040922133906.7d57ef49.davem@davemloft.net> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org > One thing that could be biting us is the nagle check which > probably needs to be adjusted to use the standard MSS not > the TSO one... perhaps play with this patch: I tried it and it breaks the performance completely (21MB/s) -Andi > > ===== include/net/tcp.h 1.88 vs edited ===== > --- 1.88/include/net/tcp.h 2004-09-14 13:57:07 -07:00 > +++ edited/include/net/tcp.h 2004-09-22 13:18:43 -07:00 > @@ -1505,7 +1505,7 @@ > * final FIN frame. -DaveM > */ > return (((nonagle&TCP_NAGLE_PUSH) || tp->urg_mode > - || !tcp_nagle_check(tp, skb, cur_mss, nonagle)) && > + || !tcp_nagle_check(tp, skb, tp->mss_cache_std, nonagle)) && > (((tcp_packets_in_flight(tp) + (pkts-1)) < tp->snd_cwnd) || > (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) && > !after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd)); > >