From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yann Droneaud Subject: Re: [PATCH v1 1/5] IB/uverbs: ex_query_device: answer must not depend on request's comp_mask Date: Fri, 30 Jan 2015 18:26:00 +0100 Message-ID: <1422638760.3133.260.camel@opteya.com> References: <24ceb1fc5b2b6563532e5776b1b2320b1ae37543.1422553023.git.ydroneaud@opteya.com> <20150129182800.GH11842@obsidianresearch.com> <1422568741.3133.247.camel@opteya.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Roland Dreier Cc: Jason Gunthorpe , Sagi Grimberg , Shachar Raindel , Eli Cohen , Haggai Eran , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org Hi, Le jeudi 29 janvier 2015 =C3=A0 15:17 -0800, Roland Dreier a =C3=A9crit= : > On Thu, Jan 29, 2015 at 1:59 PM, Yann Droneaud = wrote: > >> Roland: I agree with Yann, these patches need to go in, or the ODP > >> patches reverted. >=20 > > Reverting all On Demand Paging patches seems overkill: > > if something as to be reverted it should be commit 5a77abf9a97a > > ("IB/core: Add support for extended query device caps") and the par= t of > > commit 860f10a799c8 ("IB/core: Add flags for on demand paging suppo= rt") > > which modify ib_uverbs_ex_query_device(). >=20 > Thank you and Jason for taking on this interface. >=20 > At this point I feel like I do about the IPoIB changes -- we should > revert the broken stuff and get it right for 3.20. >=20 > If we revert the two things you describe above, is everything else OK > to leave in 3.19 with respect to ABI? >=20 I've tried to review every changes since v3.18 on drivers/infiniband include/rdma and include/uapi/rdma with respect to ABI issues. I've noticed no other issue, but I have to admit I've not well reviewed the drivers (hw/) internal changes. If the IB_USER_VERBS_EX_CMD_QUERY_DEVICE and ib_uverbs_ex_query_device changes are going to be reverted for v3.19, the on-demand-paging feature will be available (IB_DEVICE_ON_DEMAND_PAGING will be set=20 device_cap_flags in response to non extended QUERY_DEVICE for mlx5 HCA and IB_ACCESS_ON_DEMAND access flag will be effective for REG_MR=20 uverbs), but its parameters won't be. I don't know if it's a no-go for=20 the usage of on-demand paging by userspace: I have not the chance of owning HCA with the support for this feature, nor the patches libibverbs / libmlx5 ... (anyway I would not have the time to test). I've hoped people from Mellanox would have commented on the revert=20 option too. Regards. --=20 Yann Droneaud OPTEYA