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Tue, 27 Apr 2021 13:49:03 -0700 (PDT) MIME-Version: 1.0 References: <20210408170123.8788-1-logang@deltatee.com> <20210427192838.GP2047089@ziepe.ca> <52f14602-94bc-fa98-0b97-5f4084d808a0@nvidia.com> In-Reply-To: <52f14602-94bc-fa98-0b97-5f4084d808a0@nvidia.com> From: Dan Williams Date: Tue, 27 Apr 2021 13:48:58 -0700 Message-ID: Subject: Re: [PATCH 00/16] Add new DMA mapping operation for P2PDMA To: John Hubbard Cc: Jason Gunthorpe , Logan Gunthorpe , 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 , =?UTF-8?Q?Christian_K=C3=B6nig?= , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: off9t7obxew6xkw9n6maxxbue451wf7z X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: B9FF980192F1 Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf27; identity=mailfrom; envelope-from=""; helo=mail-ed1-f45.google.com; client-ip=209.85.208.45 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619556522-694194 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Apr 27, 2021 at 1:22 PM John Hubbard wrote: > > On 4/27/21 12:28 PM, Jason Gunthorpe wrote: > > On Thu, Apr 08, 2021 at 11:01:07AM -0600, Logan Gunthorpe wrote: > >> Hi, > >> > >> This patchset continues my work to to add P2PDMA support to the common > >> dma map operations. This allows for creating SGLs that have both P2PDMA > >> and regular pages which is a necessary step to allowing P2PDMA pages in > >> userspace. > >> > >> The earlier RFC[1] generated a lot of great feedback and I heard no show > >> stopping objections. Thus, I've incorporated all the feedback and have > >> decided to post this as a proper patch series with hopes of eventually > >> getting it in mainline. > >> > >> I'm happy to do a few more passes if anyone has any further feedback > >> or better ideas. > > > > For the user of the DMA API the idea seems reasonable enough, the next > > steps to integrate with pin_user_pages() seem fairly straightfoward > > too > > > > Was there no feedback on this at all? > > > > oops, I meant to review this a lot sooner, because this whole p2pdma thing is > actually very interesting and important...somehow it slipped but I'll take > a look now. Still in my queue as well behind Joao's memmap consolidation series, and a recent copy_mc_to_iter() fix series from Al.