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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 7314DC433B4 for ; Tue, 6 Apr 2021 05:09:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44417613C0 for ; Tue, 6 Apr 2021 05:09:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242672AbhDFFJz (ORCPT ); Tue, 6 Apr 2021 01:09:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:57824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230073AbhDFFJy (ORCPT ); Tue, 6 Apr 2021 01:09:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E04D2613B8; Tue, 6 Apr 2021 05:09:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617685786; bh=X92KQg3tXG2x2dhtuX1igH+EpubBIGXwmzFmddKebSI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YAkOjjj0GL3XRB09Ij60URoGO7NdIuDIosagpxtfZ9iVq8xjzpRqmg0/f2VeAwevd gCLGwz21lbIWMUVSXSoaqFi0Iru0BxK0GRYMSdNgIrMHK9Yg3XdHCPbe/mFLACsA/X UFvAfStd4Pc48XpaL+1vVCP+pCq8UiEBkUw/DIxk2rU7bNPyvyjyKgmWx+rw14jJw/ p73HiTP8ZGkD/NT+l86ADeas4d0UOfVxF9OY/sGrq+KRIXmDN6hnoJfqvKvFi3f0Bw dXBW8ogvsD7qEJhmTiZTbVWnJi+ud6+yxx8O41YQGlllSDdvvG13vLa6u7yKwxk3MU mcvvXPEGKgaVQ== Date: Tue, 6 Apr 2021 08:09:43 +0300 From: Leon Romanovsky To: Honggang LI Cc: Doug Ledford , Jason Gunthorpe , Adit Ranadive , Anna Schumaker , Ariel Elior , Avihai Horon , Bart Van Assche , Bernard Metzler , Christoph Hellwig , Chuck Lever , "David S. Miller" , Dennis Dalessandro , Devesh Sharma , Faisal Latif , Jack Wang , Jakub Kicinski , "J. Bruce Fields" , Jens Axboe , Karsten Graul , Keith Busch , Lijun Ou , linux-cifs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, Max Gurtovoy , Max Gurtovoy , "Md. Haris Iqbal" , Michael Guralnik , Michal Kalderon , Mike Marciniszyn , Naresh Kumar PBS , netdev@vger.kernel.org, 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> <20210406023738.GB80908@dhcp-128-72.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210406023738.GB80908@dhcp-128-72.nay.redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 06, 2021 at 10:37:38AM +0800, Honggang LI 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 > > Did you test this patchset with CPU does not support relaxed ordering? I don't think so, the CPUs that don't support RO are Intel's fourth/fifth-generation and they are not interesting from performance point of view. > > We observed significantly performance degradation when run perftest with > relaxed ordering enabled over old CPU. > > https://github.com/linux-rdma/perftest/issues/116 The perftest is slightly different, but you pointed to the valid point. We forgot to call pcie_relaxed_ordering_enabled() before setting RO bit and arguably this was needed to be done in perftest too. Thanks > > thanks >