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Subject: Re: [PATCH v2] io_uring: don't wait when under-submitting
To:     Pavel Begunkov <asml.silence@gmail.com>, io-uring@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <5caa38be87f069eb4cc921d58ee1a98ff5d53978.1576223348.git.asml.silence@gmail.com>
 <6256169d519f72fe592e70be47a04aa0e9c3b9a1.1576333754.git.asml.silence@gmail.com>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <55f01a72-fcbc-a3e4-d9db-7dd2a7ef1acd@kernel.dk>
Date:   Sat, 14 Dec 2019 07:39:13 -0700
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On 12/14/19 7:31 AM, Pavel Begunkov wrote:
> There is no reliable way to submit and wait in a single syscall, as
> io_submit_sqes() may under-consume sqes (in case of an early error).
> Then it will wait for not-yet-submitted requests, deadlocking the user
> in most cases.
> 
> Don't wait/poll if can't submit all sqes, and return -EAGAIN
> 
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
> 
> v2: cap min_complete if submitted partially (Jens Axboe)

Can you update the commit message as well, doesn't really reflect the
current state of it... Apart from that, looks good to me!

-- 
Jens Axboe