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Date:   Mon, 10 Jul 2023 21:59:06 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Jason Gunthorpe <jgg@ziepe.ca>,
        Mina Almasry <almasrymina@google.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Dan Williams <dan.j.williams@intel.com>,
        David Ahern <dsahern@kernel.org>,
        Jesper Dangaard Brouer <jbrouer@redhat.com>,
        brouer@redhat.com, Alexander Duyck <alexander.duyck@gmail.com>,
        Yunsheng Lin <linyunsheng@huawei.com>, davem@davemloft.net,
        pabeni@redhat.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Lorenzo Bianconi <lorenzo@kernel.org>,
        Yisen Zhuang <yisen.zhuang@huawei.com>,
        Salil Mehta <salil.mehta@huawei.com>,
        Eric Dumazet <edumazet@google.com>,
        Sunil Goutham <sgoutham@marvell.com>,
        Geetha sowjanya <gakula@marvell.com>,
        Subbaraya Sundeep <sbhatta@marvell.com>,
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        Saeed Mahameed <saeedm@nvidia.com>,
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        Felix Fietkau <nbd@nbd.name>,
        Ryder Lee <ryder.lee@mediatek.com>,
        Shayne Chen <shayne.chen@mediatek.com>,
        Sean Wang <sean.wang@mediatek.com>,
        Kalle Valo <kvalo@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        linux-rdma@vger.kernel.org, linux-wireless@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org,
        Jonathan Lemon <jonathan.lemon@gmail.com>
Subject: Re: Memory providers multiplexing (Was: [PATCH net-next v4 4/5]
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On Tue, 11 Jul 2023 06:27:08 +0200 Christoph Hellwig wrote:
> Not going to comment on the rest of this as it seems bat shit crazy
> hacks for out of tree junk.  Why is anyone even wasting time on this?

Noob question - how does RDMA integrate with the out of tree junk?
AFAIU it's possible to run the "in-tree" RDMA stack and get "GPU
direct".

Both Jonathan in the past (Meta) and now Mina (Google) are trying 
to move the needle and at least feed the GPUs over TCP, instead of
patented, proprietary and closed RDMA transports.