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[142.162.113.129]) by smtp.gmail.com with ESMTPSA id f5sm706662qtp.44.2021.09.29.16.36.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Sep 2021 16:36:25 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1mVj7g-007iwP-Pe; Wed, 29 Sep 2021 20:36:24 -0300 Date: Wed, 29 Sep 2021 20:36:24 -0300 From: Jason Gunthorpe To: Logan Gunthorpe Cc: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Stephen Bates , Christoph Hellwig , Dan Williams , Christian =?utf-8?B?S8O2bmln?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni Subject: Re: [PATCH v3 00/20] Userspace P2PDMA with O_DIRECT NVMe devices Message-ID: <20210929233624.GG3544071@ziepe.ca> References: <20210916234100.122368-1-logang@deltatee.com> <20210928200216.GW3544071@ziepe.ca> <06d75fcb-ce8b-30a5-db36-b6c108460d3d@deltatee.com> <20210929232147.GD3544071@ziepe.ca> <93f56919-03ee-8326-10ee-8fbd9078b8e0@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <93f56919-03ee-8326-10ee-8fbd9078b8e0@deltatee.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Sep 29, 2021 at 05:28:38PM -0600, Logan Gunthorpe wrote: > > > On 2021-09-29 5:21 p.m., Jason Gunthorpe wrote: > > On Wed, Sep 29, 2021 at 03:50:02PM -0600, Logan Gunthorpe wrote: > >> > >> > >> On 2021-09-28 2:02 p.m., Jason Gunthorpe wrote: > >>> On Thu, Sep 16, 2021 at 05:40:40PM -0600, Logan Gunthorpe wrote: > >>>> Hi, > >>>> > >>>> This patchset continues my work to add userspace P2PDMA access using > >>>> O_DIRECT NVMe devices. My last posting[1] just included the first 13 > >>>> patches in this series, but the early P2PDMA cleanup and map_sg error > >>>> changes from that series have been merged into v5.15-rc1. To address > >>>> concerns that that series did not add any new functionality, I've added > >>>> back the userspcae functionality from the original RFC[2] (but improved > >>>> based on the original feedback). > >>> > >>> I really think this is the best series yet, it really looks nice > >>> overall. I know the sg flag was a bit of a debate at the start, but it > >>> serves an undeniable purpose and the resulting standard DMA APIs 'just > >>> working' is really clean. > >> > >> Actually, so far, nobody has said anything negative about using the SG flag. > >> > >>> There is more possible here, we could also pass the new GUP flag in the > >>> ib_umem code.. > >> > >> Yes, that would be very useful. > > > > You might actually prefer to do that then the bio changes to get the > > infrastructur merged as it seems less "core" > > I'm a little bit more concerned about my patch set growing too large. > It's already at 20 patches and I think I'll need to add a couple more > based on the feedback you've already provided. So I'm leaning toward > pushing more functionality as future work. I mean you could postpone the three block related patches and use a single ib_umem patch instead as the consumer. Jason