From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: Re: TSO and IPoIB performance degradation Date: Wed, 8 Mar 2006 14:53:11 +0200 Message-ID: <20060308125311.GE17618@mellanox.co.il> References: <1141776697.6119.938.camel@localhost> <20060307.161808.60227862.davem@davemloft.net> <20060307.172336.107863253.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, rdreier@cisco.com, linux-kernel@vger.kernel.org, openib-general@openib.org, shemminger@osdl.org Return-path: To: "David S. Miller" Content-Disposition: inline In-Reply-To: <20060307.172336.107863253.davem@davemloft.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: openib-general-bounces@openib.org Errors-To: openib-general-bounces@openib.org List-Id: netdev.vger.kernel.org Quoting r. David S. Miller : > Subject: Re: Re: TSO and IPoIB performance degradation > > From: Roland Dreier > Date: Tue, 07 Mar 2006 17:17:30 -0800 > > > The reason TSO comes up is that reverting the patch described below > > helps (or helped at some point at least) IPoIB throughput quite a bit. > > I wish you had started the thread by mentioning this specific patch Er, since you mention it, the first message in thread did include this link: http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=314324121f9b94b2ca657a494cf2b9cb0e4a28cc and I even pasted the patch description there, but oh well. Now that Roland helped us clear it all up, and now that it has been clarified that reverting this patch gives us back most of the performance, is the answer to my question the same? What I was trying to figure out was, how can we re-enable the trick without hurting TSO? Could a solution be to simply look at the frame size, and call tcp_send_delayed_ack if the frame size is small? -- Michael S. Tsirkin Staff Engineer, Mellanox Technologies