From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: [PATCH rdma-next 0/4] Add packet pacing support for IB verbs Date: Thu, 10 Nov 2016 09:22:42 +0200 Message-ID: <20161110072242.GC28957@leon.nu> References: <1477909297-14491-1-git-send-email-leon@kernel.org> <1828884A29C6694DAF28B7E6B8A82373AB0A7B31@ORSMSX109.amr.corp.intel.com> <20161109064009.GE27883@leon.nu> <1828884A29C6694DAF28B7E6B8A82373AB0A7F0A@ORSMSX109.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="KDt/GgjP6HVcx58l" Return-path: Content-Disposition: inline In-Reply-To: <1828884A29C6694DAF28B7E6B8A82373AB0A7F0A-P5GAC/sN6hkd3b2yrw5b5LfspsVTdybXVpNB7YpNyf8@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Hefty, Sean" , Bodong Wang Cc: "dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org" , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-rdma@vger.kernel.org --KDt/GgjP6HVcx58l Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Nov 09, 2016 at 05:06:52PM +0000, Hefty, Sean wrote: > > On Tue, Nov 08, 2016 at 05:49:26PM +0000, Hefty, Sean wrote: > > > > When sending from a 10G host to a 1G host, it is easy to overrun > > the > > > > receiver, > > > > leading to packet loss and traffic backing off. Similar problems > > occur > > > > when > > > > a 10G host sends data to a sub-10G virtual circuit, or a 40G host > > > > sending > > > > to a 10G host. Packet pacing could control packet injection rate > > and > > > > reduces > > > > network congestion to maximize throughput & minimize network > > latency. > > > > > > Why isn't the path record data and existing mechanisms sufficient to > > handle this? > > > > > > > Packet pacing allows different combinations of traffic shaping: per- > > CPU, > > per-flow and their combinations with better and steady QoS requirements > > without involving subnet management. > > The patch adds this as a QP attribute, and we already have a rate for that. I still don't see why the standard mechanisms are insufficient or couldn't be adapted. I'll let to Bodong to elaborate on it more, but as far as I see, the AH attribute is relevant to UD QP only, while the packet pacing is intended for all types of QPs. Thanks --KDt/GgjP6HVcx58l Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJYJCBCAAoJEORje4g2clin/IUP/RpcCL9SClpBTYSmR+Zm3FQ5 trPJMlZyoPVpEfGDCegKkUaIwMTZbEgg6DRSIU+OuVlfWX3doQJKcVUEhW7FwREn H04/0XczjWx98RKo50UL3Hu701dhoXWKJZm9Lrjvh3k2Mw2Z82g05P/Ob8UdHhx0 qjCf6roD+ez1phNYA+hQwPlB+W7+LGs2qfxsUJKvFPqWJEnlGv7SXVWCPSQhO5WP G1w5plljbJZzwJjfwxMj751Wyh0zEq+Kb9/8OOhJ8RnPthYeZwSw/nrVaZWWOjEn K44RyUucsYSGT2QVFE6ffjthGV5NdYCC1AwrbF+4zAXekMntprx4xUFKuCq1oFgZ zRYWimXdlM0IQEhdqja9ApLv/+VE3Jc4AklYsI3GNWzFwCPqAziPHHyWQbuGWrnJ dGR4/rmcZXhLaqwyJWkhm8YCVPjneP9HJRcNQSV3V1YBSyBJT6uS6KAyfD8W9yuI 7N/YWAuPIaJV+OnKwNjKm47/S/HE9oxe3SAwSyU3sqr1ArVZHLPz59XSwqtLloST l1sSWqSg1BtnbldScqTqURHKw/PI4Q5KSg+nUPyX/JZkp1KVTlIhgs/QtVsG9Uxn l/KOJ66Na9Gj8tSxvdSgvoKyFdDL/V85HNf3pqxjuVKViRUnae9E2PczLgfHNcQt d67lngBCAORyJoAEbxtO =J+z9 -----END PGP SIGNATURE----- --KDt/GgjP6HVcx58l-- -- 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