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Date:   Tue, 9 Aug 2022 08:18:45 -0600
From:   Keith Busch <kbusch@kernel.org>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Keith Busch <kbusch@fb.com>, linux-nvme@lists.infradead.org,
        linux-block@vger.kernel.org, io-uring@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, axboe@kernel.dk,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Kernel Team <Kernel-team@fb.com>
Subject: Re: [PATCHv3 0/7] dma mapping optimisations
Message-ID: <YvJsxZucjbQmEZP8@kbusch-mbp.dhcp.thefacebook.com>
References: <20220805162444.3985535-1-kbusch@fb.com>
 <20220809064613.GA9040@lst.de>
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On Tue, Aug 09, 2022 at 08:46:13AM +0200, Christoph Hellwig wrote:
>  - the design seems to ignore DMA ownership.  Every time data in
>    transfered data needs to be transferred to and from the device,
>    take a look at Documentation/core-api/dma-api.rst and
>    Documentation/core-api/dma-api-howto.rst.

I have this doing appropriate dma_sync_single_for_{device,cpu} if we aren't
using coherent memory. Is there more to ownership beyond that?