From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [PATCH for-4.3] IB/ipoib: add module option for auto-creating mcast groups Date: Tue, 15 Sep 2015 14:24:21 -0400 Message-ID: <55F86255.9080508@redhat.com> References: <980e8b0a82042d7e5801e02bf16fe72a0bde6759.1441934465.git.dledford@redhat.com> <20150911182115.GA546@obsidianresearch.com> <55F32E7A.3020105@redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SRENiQ45nX0N73a5NWFgjMptF3BQAtHxh" Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Christoph Lameter Cc: Jason Gunthorpe , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Or Gerlitz List-Id: linux-rdma@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --SRENiQ45nX0N73a5NWFgjMptF3BQAtHxh Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 09/14/2015 01:03 PM, Christoph Lameter wrote: > On Fri, 11 Sep 2015, Doug Ledford wrote: >=20 >>> At a minimum, when the socket that did the send closes the send-only >>> could be de-refed.. >> >> If we kept a ref count, but we don't. Tracking this is not a small ch= ange. >=20 > We could call ip_mc_join_group() from ipoib_mcast_send() which would jo= in > it at the socket layer. That layer would do the tracking for us and lea= ve the > group when the process terminates. The join would be visible the same w= ay > as if one would have done an explicit setsockopt(). I actually think this is a step in the right direction, but I think we are talking about a layering violation doing it the way you are suggesting. What's more, there are a few difficulties here in that I'm fairly certain the core networking layer doesn't have the concept of a send-only join, yet we would need it to have such. If we had three apps do send only sends, we would need to track all three of those sockets as being send only socket joins, and then if someone did a full join, we would need to automatically upgrade the join, and then if that app with the full join left, we would need to gracefully downgrade to send only again. So, I think it would take work at the core level to get this right, but I think that's probably the right place to do the work. --=20 Doug Ledford GPG KeyID: 0E572FDD --SRENiQ45nX0N73a5NWFgjMptF3BQAtHxh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJV+GJVAAoJELgmozMOVy/dfJ0P/0RWMr/Fzqjf27JIrSFMB3QT 8JV4eW9bcgPaPjb+AZIxEfa9/LTNG2p8ro3AmPTkMy97bQu+mK86KNg99SgBJmrc Vc2SHWaBmczACYF5UXSIs5H14NI+FGh25zy4wfzLFNssTF0dxQ8nLW5uvMpJ4EKw IE0biRIcoxySN3Qa4SxC5AGzATcGXgSQMIpCRMc6QwCX/qHe3FZtWxcZE/4QD/IX QbxS/OrDcrOjWc9AwpT1yN4HYixpPMuybP7FJzYarPGXtrCIiiM47Pm3Zwsg+bIu q3O1VSyjzKSEUAcKUZzCBcClnoFF5bm0D7KH0X4XWDhj8WSgtYVUi43fuAFYjy2K nLSELNPXMO8/8C2/HF3OuUC+W5RBM+WSIQ4vGHYfWejzs4qcyuNmEh/+UzfJadDs W3jRqVwqsQFG43XQWnhTgXg0fHHndDB+6LJTTpR0nxOkNSxgzVD5ZVCpI1NPkHFF /SegCQTBRUvUV1LCsqQdBPgFfqkt+Y9huVw3f8wO4ckJlCybKgrNwf5kK6RuWFzA KYb+ZMzwGt2cAncDOmldmWTi4naRLJseMg7FGDuamsQuje3Y8Ukb0hXYpWjcLxIx NcKT5ZbWnXY3C3hGqRYO4lx64upwd7sXXXR7GcjvP8OC/cax1M4mKRo+WqT0U3cW DYFKd66hXnEEOm6cpBk6 =lFjK -----END PGP SIGNATURE----- --SRENiQ45nX0N73a5NWFgjMptF3BQAtHxh-- -- 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