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Date:   Mon, 6 Nov 2023 16:55:43 -0700
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Subject: Re: [RFC PATCH v3 10/12] tcp: RX path for devmem TCP
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To:     Stanislav Fomichev <sdf@google.com>,
        Willem de Bruijn <willemdebruijn.kernel@gmail.com>
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On 11/6/23 4:32 PM, Stanislav Fomichev wrote:
>> The concise notification API returns tokens as a range for
>> compression, encoding as two 32-bit unsigned integers start + length.
>> It allows for even further batching by returning multiple such ranges
>> in a single call.
> 
> Tangential: should tokens be u64? Otherwise we can't have more than
> 4gb unacknowledged. Or that's a reasonable constraint?
> 

Was thinking the same and with bits reserved for a dmabuf id to allow
multiple dmabufs in a single rx queue (future extension, but build the
capability in now). e.g., something like a 37b offset (128GB dmabuf
size), 19b length (large GRO), 8b dmabuf id (lots of dmabufs to a queue).