From mboxrd@z Thu Jan 1 00:00:00 1970 From: Knut Omang Subject: Re: [PATCH libibverbs 1/3] Add new call ibv_cmd_create_ah_ex which supports extra parameters Date: Thu, 01 Sep 2016 20:23:40 +0200 Message-ID: <1472754220.9410.236.camel@oracle.com> References: <1472713193-22397-1-git-send-email-knut.omang@oracle.com> <1472713193-22397-2-git-send-email-knut.omang@oracle.com> <20160901164939.GD6479@obsidianresearch.com> <1472750558.9410.230.camel@oracle.com> <20160901180512.GB20098@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160901180512.GB20098-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Cc: Doug Ledford , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mukesh Kacker List-Id: linux-rdma@vger.kernel.org On Thu, 2016-09-01 at 12:05 -0600, Jason Gunthorpe wrote: > On Thu, Sep 01, 2016 at 07:22:38PM +0200, Knut Omang wrote: > > On Thu, 2016-09-01 at 10:49 -0600, Jason Gunthorpe wrote: > > > On Thu, Sep 01, 2016 at 08:59:51AM +0200, Knut Omang wrote: > > > > +++ b/src/libibverbs.map > > > > @@ -64,6 +64,7 @@ IBVERBS_1.0 { > > > > ibv_cmd_post_recv; > > > > ibv_cmd_post_srq_recv; > > > > ibv_cmd_create_ah; > > > > + ibv_cmd_create_ah_ex; > > > > > > I should also point out that this is not the proper way to use symbol > > > versions. Typically one would tag new symbols with the version number > > > of the release that introduces them, and not just keep re-using 1.0 > > > > > > I know we haven't been doing that, but perhaps we should start. > > > > Yes, I noticed the never changed 1.0 and tried just to follow the usage > > pattern ;-) > > Actually, thinking about this more, not doing this properly breaks RPM > since it only summarizes the tag not the actual symbol into the > package data. > > So, no this is not OK, and maybe we need to retroactively review > things :( :( For this patch backward binary compatibility is actually preserved - a vendor library continues to work even without recompiling. I deliberately avoided making the ibv_cmd_create_ah function inline to ensure that. Loading libsif would of course break, but with a symbol error. But versioning is still an issue to consider with patch 2 in this set, as it unfortunately has to change the layout of the data structures between kernel and user space to fix the alignment bug. Patch 3 has the same alignment issue, but is not used by anyone but our new vendor library. Knut > 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