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Subject: Re: [PATCH for-5.18 v1 0/3] Add `sendto(2)` and `recvfrom(2)` support
To:     Ammar Faizi <ammarfaizi2@gnuweeb.org>
Cc:     io-uring Mailing List <io-uring@vger.kernel.org>,
        netdev Mailing List <netdev@vger.kernel.org>,
        GNU/Weeb Mailing List <gwml@gnuweeb.org>,
        Tea Inside Mailing List <timl@vger.teainside.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Pavel Begunkov <asml.silence@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, Nugra <richiisei@gmail.com>,
        Praveen Kumar <kpraveen.lkml@gmail.com>,
        Alviro Iskandar Setiawan <alviro.iskandar@gmail.com>
References: <20220129125021.15223-1-ammarfaizi2@gnuweeb.org>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <98d4f268-5945-69a7-cec7-bccfcdedde1c@kernel.dk>
Date:   Sat, 29 Jan 2022 11:32:21 -0700
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On 1/29/22 5:50 AM, Ammar Faizi wrote:
> Hello,
> 
> This patchset adds sendto(2) and recvfrom(2) support for io_uring. It
> also addresses an issue in the liburing GitHub repository [1].
> 
> ## Motivations:
> 
> 1) By using `sendto()` and `recvfrom()` we can make the submission
>    simpler compared to always using `sendmsg()` and `recvmsg()` from
>    the userspace. Especially for UDP socket.
> 
> 2) There is a historical patch that tried to add the same
>    functionality, but did not end up being applied. [2]

As far as I can tell, the only win from sendto/recvfrom is that we can
handle async offload a bit cheaper compared to sendmsg/recvmsg. Is this
enough to warrant adding them separately? I don't know, which is why
this has been somewhat stalled for a while.

Maybe you have done some testing and have numbers (or other reasons) to
back up the submission? There's not a whole lot of justification in this
patchset.

-- 
Jens Axboe