From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: [PATCH RFC 2/2] RDMA/nldev: provide detailed CM_ID information Date: Mon, 5 Feb 2018 17:43:51 +0200 Message-ID: <20180205154351.GG2567@mtr-leonro.local> References: <531889e6a24f7919dec71734c91298d266aa9721.1517418595.git.swise@opengridcomputing.com> <20180201084944.GH2055@mtr-leonro.local> <00ce01d39b76$bd374ac0$37a5e040$@opengridcomputing.com> <20180204150553.GH27780@mtr-leonro.local> <015301d39e96$9f5e0b60$de1a2220$@opengridcomputing.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Yb+qhiCg54lqZFXW" Return-path: Content-Disposition: inline In-Reply-To: <015301d39e96$9f5e0b60$de1a2220$@opengridcomputing.com> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Steve Wise Cc: dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, jgg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org --Yb+qhiCg54lqZFXW Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Feb 05, 2018 at 09:33:07AM -0600, Steve Wise wrote: > Hey Leon, > > > > > It is opposite, cm_id is a unique number, but other objects don't have > > such. What about PD and CQ? > > > > We can declare that access to QP .doit willbe based on QPN, PD .doit > > will be based on local_dma_lkey, but what will be CQ identifier? > > > > Now that I've thought about this more, I realize the core verbs data > structures don't have identifiers for most objects. I'm not sure why the > qp_num is exposed, but I guess it is because the qp num values must be > exchanged between both ends of an IB connection to setup the connection. > > The local_dma_lkey value will not be unique for each PD. For all iwarp > devices the local_dma_lkey is 0. (I think the same is true for IB devices). > So PD has the same issue as CQ. > > I suppose we can use rkey for MRs, but if the MR is not in the VALID state, > the rkey isn't necessarily accurate (the LSB of the rkey can be changed by > the application with each REG_MR operation). > > The cm_id doesn't have any unique identifier either, except maybe the > combination of src/dst addresses and port space. > > With iw_cxgb4, CQs, PDs, and MRs all have a unique identifier just like a QP > does. I expect all hw implementations of rdma have numeric identifiers for > CQs, PDs, QPs, etc. They aren't exposed to the core API though. > > Perhaps we add a device-unique (or globally unique) identifier as part of > the restrack struct and use that for GET/SET? +1, I like it, it is very clean. Thanks > > Steve. > --Yb+qhiCg54lqZFXW Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEkhr/r4Op1/04yqaB5GN7iDZyWKcFAlp4e7YACgkQ5GN7iDZy WKc4xhAApemk183DJiyaXenOYQM2my+gONiU0UK6AOF1MH8cNCf2lfAgTimqRkOW tMFBpdrIjS7dwpVcBrqLx3Gyn+AyZnYnq3UO+oqkwLotIoFmJDNCP01GwZnHQUT8 sYolP+TQPkSLp7hJJ7vfct+t5lZfLNBjnEfJS5J9Y7N16lbtVkH7Q0pLWPyLtU9S aC00h3O4okj3hRO2U08uJOLB6BLbNxEPa+rrcHP2xNNKr0nD7YoXQfpHA+2Ddgh3 tNwkDYUVv8WmzsHGrfkPc3VX17852X6nsdOv71oU93mtluNRgxCS4UtIFMRX2VjZ +5WuLEgl5ch5v1RkJXc4JPsax2s/oswbO16ViaPOSaQ8K5TKsq8Cv5By21sPCfJf cFrvnRmlzAoa6Kj6pfxRS1MHXAz3gFRHISlkvRzc5R0HNUVDHp7wccPjuZgegdhX +24Xsj3FhctSJHbx5niSYCyiGVJSTNWo7qJr4YocVlB9Y/EBty0Vxiwaq8IVSfrg PwoKYEmdGZ583IiughjClYQlArRnHA2Gl7zum45PFL7zRWeQwYrTYfrDOgsTIuGB a15fN1S48GPC5V/bVlyHhXwP409CbxvEYkgUAvvf7B59rR2nLqKzt5NOZ1wIbHHy MGREl0A95yhJWLEzMXDy0iwAXVzr8wH3+gOE4AGL7DirTcY3QoA= =CIOl -----END PGP SIGNATURE----- --Yb+qhiCg54lqZFXW-- -- 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