From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH] DAPL v2.0: common: increase default IB ack timer from 16 to 20 Date: Wed, 2 Nov 2011 20:28:22 -0600 Message-ID: <20111103022822.GA6674@obsidianresearch.com> References: <54347E5A035A054EAE9D05927FB467F916E93128@ORSMSX101.amr.corp.intel.com> <1828884A29C6694DAF28B7E6B8A8237316E8CBCB@ORSMSX101.amr.corp.intel.com> <54347E5A035A054EAE9D05927FB467F916E931C5@ORSMSX101.amr.corp.intel.com> <1828884A29C6694DAF28B7E6B8A8237316E8CC00@ORSMSX101.amr.corp.intel.com> <54347E5A035A054EAE9D05927FB467F916E931E8@ORSMSX101.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <54347E5A035A054EAE9D05927FB467F916E931E8-P5GAC/sN6hmkrb+BlOpmy7fspsVTdybXVpNB7YpNyf8@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Davis, Arlin R" Cc: "Hefty, Sean" , linux-rdma , "ofw-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org" List-Id: linux-rdma@vger.kernel.org On Wed, Nov 02, 2011 at 11:31:38PM +0000, Davis, Arlin R wrote: > > > Yes, a user can modify path lifetime via rdma_create_ep() but there > > > is no way for the user to know how much that will be manipulated and > > > increased in the IB CM driver. > > > > Sure there is. It's an open source driver. :) > > > > The ib_cm calculates the "correct" timeout based on the packet lifetime > > provided by the SA and the CA ack timeout. If user modifications to > > this value are necessary, then there is a bug in either the SA or HCA > > driver. > > or there could be congestion on the fabric that the SA or HCA driver > is unaware of. That is what packet life time is supposed to model, and the policy knob for it belongs in the SA, not every app.. 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