From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26172C43461 for ; Tue, 6 Apr 2021 05:12:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E74E76139B for ; Tue, 6 Apr 2021 05:12:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231172AbhDFFMn (ORCPT ); Tue, 6 Apr 2021 01:12:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:58382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229808AbhDFFMn (ORCPT ); Tue, 6 Apr 2021 01:12:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 23138613B8; Tue, 6 Apr 2021 05:12:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617685956; bh=K2VXUKEpqJiAecRK7nuM6Ef1vGTf004NIHw7LA9Q4Xw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VBYe8nAhcQ2gETbrZBaxITiulHS0SsxOuZB1nNAi0p5WY3rfrHLnaPjo9tL4+RatD OvfjqH3Povn5OCMTGa5RlQF230tFVVzb9HydS2zHU/BaIwf+KvMdYr32GN/VwJ25lZ dsH93XLOHPu2URUPt9RBiTbVY7N/Y4wAJjBYAyqNIJ4GDgORdUjoFJY+r6Xs8g41uZ 4jIsVc7rfnYGLju9XB1n4Nq+dsoRUWnYUZWddt9/CZ7cajg1idzkiXvRRAIvS4sPp/ Kr6vAgYC12rpER13ZxiNVcQcpTQ3wJHz0xG14EeFWCDKjzO9gYBWR6BNYBQA3n7iO9 WILNU27QNSjSw== Date: Tue, 6 Apr 2021 08:12:32 +0300 From: Leon Romanovsky To: Chuck Lever III Cc: Jason Gunthorpe , Christoph Hellwig , Doug Ledford , Adit Ranadive , Anna Schumaker , Ariel Elior , Avihai Horon , Bart Van Assche , Bernard Metzler , "David S. Miller" , Dennis Dalessandro , Devesh Sharma , Faisal Latif , Jack Wang , Jakub Kicinski , Bruce Fields , Jens Axboe , Karsten Graul , Keith Busch , Lijun Ou , CIFS , LKML , Linux NFS Mailing List , "linux-nvme@lists.infradead.org" , linux-rdma , "linux-s390@vger.kernel.org" , Max Gurtovoy , Max Gurtovoy , "Md. Haris Iqbal" , Michael Guralnik , Michal Kalderon , Mike Marciniszyn , Naresh Kumar PBS , Linux-Net , Potnuri Bharat Teja , "rds-devel@oss.oracle.com" , Sagi Grimberg , "samba-technical@lists.samba.org" , Santosh Shilimkar , Selvin Xavier , Shiraz Saleem , Somnath Kotur , Sriharsha Basavapatna , Steve French , Trond Myklebust , VMware PV-Drivers , Weihang Li , Yishai Hadas , Zhu Yanjun Subject: Re: [PATCH rdma-next 00/10] Enable relaxed ordering for ULPs Message-ID: References: <20210405052404.213889-1-leon@kernel.org> <20210405134115.GA22346@lst.de> <20210405200739.GB7405@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Mon, Apr 05, 2021 at 11:42:31PM +0000, Chuck Lever III wrote: > > > > On Apr 5, 2021, at 4:07 PM, Jason Gunthorpe wrote: > > > > On Mon, Apr 05, 2021 at 03:41:15PM +0200, Christoph Hellwig wrote: > >> On Mon, Apr 05, 2021 at 08:23:54AM +0300, Leon Romanovsky wrote: > >>> From: Leon Romanovsky > >>> > >>>> From Avihai, > >>> > >>> Relaxed Ordering is a PCIe mechanism that relaxes the strict ordering > >>> imposed on PCI transactions, and thus, can improve performance. > >>> > >>> Until now, relaxed ordering could be set only by user space applications > >>> for user MRs. The following patch series enables relaxed ordering for the > >>> kernel ULPs as well. Relaxed ordering is an optional capability, and as > >>> such, it is ignored by vendors that don't support it. > >>> > >>> The following test results show the performance improvement achieved > >>> with relaxed ordering. The test was performed on a NVIDIA A100 in order > >>> to check performance of storage infrastructure over xprtrdma: > >> > >> Isn't the Nvidia A100 a GPU not actually supported by Linux at all? > >> What does that have to do with storage protocols? > > > > I think it is a typo (or at least mit makes no sense to be talking > > about NFS with a GPU chip) Probably it should be a DGX A100 which is a > > dual socket AMD server with alot of PCIe, and xptrtrdma is a NFS-RDMA > > workload. > > We need to get a better idea what correctness testing has been done, > and whether positive correctness testing results can be replicated > on a variety of platforms. I will ask to provide more details. > > I have an old Haswell dual-socket system in my lab, but otherwise > I'm not sure I have a platform that would be interesting for such a > test. We don't have such old systems too. > > > > AMD dual socket systems are well known to benefit from relaxed > > ordering, people have been doing this in userspace for a while now > > with the opt in. > > > -- > Chuck Lever > > >