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Date:   Thu, 30 Jun 2022 14:19:11 -0600
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Subject: Re: [PATCH v2 for-next 00/12] io_uring: multishot recv
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To:     Dylan Yudaken <dylany@fb.com>,
        Pavel Begunkov <asml.silence@gmail.com>,
        io-uring@vger.kernel.org
Cc:     Kernel-team@fb.com, linux-kernel@vger.kernel.org
References: <20220630091231.1456789-1-dylany@fb.com>
From:   Jens Axboe <axboe@kernel.dk>
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On 6/30/22 3:12 AM, Dylan Yudaken wrote:
> This series adds support for multishot recv/recvmsg to io_uring.
> 
> The idea is that generally socket applications will be continually
> enqueuing a new recv() when the previous one completes. This can be
> improved on by allowing the application to queue a multishot receive,
> which will post completions as and when data is available. It uses the
> provided buffers feature to receive new data into a pool provided by
> the application.
> 
> This is more performant in a few ways:
> * Subsequent receives are queued up straight away without requiring the
>   application to finish a processing loop.
> * If there are more data in the socket (sat the provided buffer
>   size is smaller than the socket buffer) then the data is immediately
>   returned, improving batching.
> *  Poll is only armed once and reused, saving CPU cycles
> 
> Running a small network benchmark [1] shows improved QPS of ~6-8% over
> a range of loads.

I have applied this, changing ->addr2 to ->ioprio for the flags bit as
per the io_uring-5.19 branch.

Pretty excited about recv multishot. I think it's an elegant model, and
it has really nice performance improvements as well!

-- 
Jens Axboe