From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Abeni Subject: Re: [PATCH] IB/ipoib: move back the IB LL address into the hard header Date: Tue, 11 Oct 2016 19:52:01 +0200 Message-ID: <1476208321.448.5.camel@redhat.com> References: <1dbd83dfe7f435eecc5bc460e901b47758280f30.1476206016.git.pabeni@redhat.com> <20161011173216.GA16892@obsidianresearch.com> <1476207452.448.2.camel@redhat.com> <20161011174224.GA17319@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Doug Ledford , Sean Hefty , Hal Rosenstock , netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Return-path: In-Reply-To: <20161011174224.GA17319-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org On Tue, 2016-10-11 at 11:42 -0600, Jason Gunthorpe wrote: > On Tue, Oct 11, 2016 at 07:37:32PM +0200, Paolo Abeni wrote: > > On Tue, 2016-10-11 at 11:32 -0600, Jason Gunthorpe wrote: > > > On Tue, Oct 11, 2016 at 07:15:44PM +0200, Paolo Abeni wrote: > > > > > > > Also the connected mode maximum mtu is reduced by 16 bytes to > > > > cope with the increased hard header len. > > > > > > Changing the MTU is going to cause annoying interop problems, can you > > > avoid this? > > > > I don't like changing the maximum MTU value, too, but I was unable to > > find an alternative solution. The PMTU detection should protect against > > such issues. > > It is more that PMTU, we have instructed all users that is the MTU > number needed to enable CM mode, so it appears in documentation, > scripts, etc. AFAICS the max mtu is already underlying h/w dependent, how does such differences are currently coped by ? (I'm sorry I lack some/a lot of IB back-ground) -- 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