From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH] IB/ipoib: CSUM support in connected mode Date: Thu, 30 Jul 2015 11:15:38 -0600 Message-ID: <20150730171538.GA25282@obsidianresearch.com> References: <1438256764-9077-1-git-send-email-yuval.shaia@oracle.com> <1438264693.9344.19.camel@opteya.com> <20150730152049.GA29102@yuval-lab> <55BA47F0.5080504@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <55BA47F0.5080504-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Doug Ledford Cc: Yuval Shaia , Yann Droneaud , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On Thu, Jul 30, 2015 at 11:51:12AM -0400, Doug Ledford wrote: > In its current state, I have my doubts about this patch. However, it > seems to me that this should be relatively easy to fix in such a way > that you get 90%+ of the performance benefit, and can turn it on by > default, and we don't cause any problems. The best way to implement this is to leverage all the checksum offload work people did for virtualization. Forward the checksum offload status through the RC connection and recover it on the other side. Then the far side stack will know it is dealing with a partial checksum packet and will properly regenerate the checksum if it re-transmits. ie doing it this way doesn't totally break the netstack :) Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html