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Subject: Re: [PATCH 00/16] Add new DMA mapping operation for P2PDMA
To:     Logan Gunthorpe <logang@deltatee.com>,
        <linux-kernel@vger.kernel.org>, <linux-nvme@lists.infradead.org>,
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CC:     Stephen Bates <sbates@raithlin.com>,
        Christoph Hellwig <hch@lst.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>,
        Don Dutile <ddutile@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        Daniel Vetter <daniel.vetter@ffwll.ch>,
        Jakowski Andrzej <andrzej.jakowski@intel.com>,
        Minturn Dave B <dave.b.minturn@intel.com>,
        Jason Ekstrand <jason@jlekstrand.net>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Xiong Jianxin <jianxin.xiong@intel.com>,
        Bjorn Helgaas <helgaas@kernel.org>,
        Ira Weiny <ira.weiny@intel.com>,
        Robin Murphy <robin.murphy@arm.com>
References: <20210408170123.8788-1-logang@deltatee.com>
From:   John Hubbard <jhubbard@nvidia.com>
Message-ID: <5f15dc88-fefd-e2db-8c0b-6f7b84826749@nvidia.com>
Date:   Sat, 1 May 2021 18:22:43 -0700
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On 4/8/21 10:01 AM, 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.
> 

After an initial pass through these, I think I like the approach. And I
don't have any huge structural comments or new ideas, just smaller comments
and notes.

I'll respond to each patch, but just wanted to say up front that this is
looking promising, in my opinion.


thanks,
-- 
John Hubbard
NVIDIA