Return-Path: Received: from quartz.orcorp.ca ([184.70.90.242]:39663 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751344AbbCaXMd (ORCPT ); Tue, 31 Mar 2015 19:12:33 -0400 Date: Tue, 31 Mar 2015 17:12:02 -0600 From: Jason Gunthorpe To: Doug Ledford Cc: Michael Wang , Roland Dreier , Sean Hefty , Hal Rosenstock , Ira Weiny , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, "J. Bruce Fields" , Trond Myklebust , "David S. Miller" , Or Gerlitz , Moni Shoua , PJ Waskiewicz , Tatyana Nikolova , Yan Burman , Jack Morgenstein , Bart Van Assche , Yann Droneaud , Colin Ian King , Majd Dibbiny , Jiri Kosina , Matan Barak , Alex Estrin , Eric Dumazet , Erez Shitrit , Sagi Grimberg , Haggai Eran , Shachar Raindel , Mike Marciniszyn , Steve Wise , Tom Tucker , Chuck Lever Subject: Re: [RFC PATCH 06/11] IB/Verbs: Use management helper has_sa() and cap_sa(), for sa-check Message-ID: <20150331231202.GA20094@obsidianresearch.com> References: <551579CA.4030901@profitbricks.com> <55157B43.6060507@profitbricks.com> <1427732191.21101.201.camel@redhat.com> <55197CDB.3040105@profitbricks.com> <1427734923.21101.227.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1427734923.21101.227.camel@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Mar 30, 2015 at 01:02:03PM -0400, Doug Ledford wrote: > If we use something like this, then the above is all you need. Then > every place in the code that checks for something like has_sa or cap_sa > can be replaced with rdma_ib_mgmt. I don't want to see this slide back into some ill defined feature test. We need to clearly define exactly what these tests are checking, and I think, since we have so much code sharing, the checks should be narrow in scope, not just an entire standard. I think the basic family of checks Michael identified seemed like a reasonable start. Going forward we want to NAK stuff like this: if (rdma_ib_mgmt() || rdma_opa_mgmt()) if (has_sa() || has_opa_foobar()) That indicates we need a new micro feature test. A big problem here is people working on the core may not know the intricate details of all the families. This will only get worse when proprietary tech like OPA gets added. Documenting requirements via a narrow feature test gives a much higher chance that core stuff will be right via review. > But, like I said, this is an all or nothing change, it isn't > something we can ease into. Well, we ease into it by introducing the micro tests and then wiping the legacy ones, followed by changing how the driver/core communicates the port and device feature set, ideally to a bitset like you've described. Michael has tackled the core code, another series could work on the drivers.. Jason