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Message-ID: <86a768ba44d3d2009c313bd2b7ddf25e2a3f4b5e.camel@trillion01.com>
Subject: Re: [PATCH v2] io_uring: reduce latency by reissueing the operation
From:   Olivier Langlois <olivier@trillion01.com>
To:     Pavel Begunkov <asml.silence@gmail.com>,
        Jens Axboe <axboe@kernel.dk>, io-uring@vger.kernel.org,
        linux-kernel@vger.kernel.org
Date:   Sun, 20 Jun 2021 17:05:48 -0400
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         <61668060-6401-ccc0-06e8-29d6320b720a@gmail.com>
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On Sun, 2021-06-20 at 20:56 +0100, Pavel Begunkov wrote:
> On 6/20/21 8:05 PM, Olivier Langlois wrote:
> > 
> > ?
> > -static bool io_arm_poll_handler(struct io_kiocb *req)
> > +#define IO_ARM_POLL_OK??? 0
> > +#define IO_ARM_POLL_ERR?? 1
> > +#define IO_ARM_POLL_READY 2
> 
> Please add a new line here. Can even be moved somewhere
> to the top, but it's a matter of taste.

If you let me decide, I prefer to let them close to where they are
used. There is so much data definitions in the heading section that I
feel like putting very minor implementation details to it might
overwhelm newcomers instead of helping them to grasp the big picture.

but I will add an extra space as you request
> 
> Also, how about to rename it to apoll? io_uring internal
> rw/send/recv polling is often abbreviated as such around
> io_uring.c
> IO_APOLL_OK and so on.

no problem. I will.
> 
> > +static int io_arm_poll_handler(struct io_kiocb *req)
> > ?{
> > ????????const struct io_op_def *def = &io_op_defs[req->opcode];
> > ????????struct io_ring_ctx *ctx = req->ctx;
> > @@ -5153,22 +5156,22 @@ static bool io_arm_poll_handler(struct
> > io_kiocb *req)
> > ????????int rw;
> > ?
> > ????????if (!req->file || !file_can_poll(req->file))
> > -???????????????return false;
> > +???????????????return IO_ARM_POLL_ERR;
> 
> It's not really an error. Maybe IO_APOLL_ABORTED or so?

Ok.