From: Christoph Hellwig <hch@lst.de>
To: Breno Leitao <leitao@debian.org>
Cc: Christoph Hellwig <hch@lst.de>,
io-uring@vger.kernel.org, linux-nvme@lists.infradead.org,
asml.silence@gmail.com, axboe@kernel.dk, leit@fb.com,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
sagi@grimberg.me, kbusch@kernel.org, ming.lei@redhat.com
Subject: Re: [PATCH 1/2] io_uring: Pass whole sqe to commands
Date: Thu, 20 Apr 2023 14:31:39 +0200 [thread overview]
Message-ID: <20230420123139.GA32030@lst.de> (raw)
In-Reply-To: <ZEEwHk32Y8IcT20n@gmail.com>
On Thu, Apr 20, 2023 at 05:29:18AM -0700, Breno Leitao wrote:
> > > - cmd_size = uring_cmd_pdu_size(req->ctx->flags & IORING_SETUP_SQE128);
> > > + if (req->ctx->flags & IORING_SETUP_SQE128)
> > > + size <<= 1;
> >
> >
> > Why does this stop using uring_cmd_pdu_size()?
>
> Before, only the cmd payload (sqe->cmd) was being copied to the async
> structure. We are copying over the whole sqe now, since we can use SQE
> fields inside the ioctl callbacks (instead of only cmd fields). So, the
> copy now is 64 bytes for single SQE or 128 for double SQEs.
That's the point of this series and I get it. But why do we remove
the nice and self-documenting helper that returns once or twice
the sizeof of the SQE structure and instead add a magic open coded
left shift?
next prev parent reply other threads:[~2023-04-20 12:32 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-19 10:29 [PATCH 0/2] io_uring: Pass whole sqe to commands Breno Leitao
2023-04-19 10:29 ` [PATCH 1/2] " Breno Leitao
2023-04-20 4:57 ` Christoph Hellwig
2023-04-20 12:29 ` Breno Leitao
2023-04-20 12:31 ` Christoph Hellwig [this message]
2023-04-20 12:38 ` Breno Leitao
2023-04-20 12:46 ` Christoph Hellwig
2023-04-30 14:37 ` Breno Leitao
2023-04-21 15:11 ` Breno Leitao
2023-04-24 5:08 ` Christoph Hellwig
2023-04-19 10:29 ` [PATCH 2/2] io_uring: Remove unnecessary BUILD_BUG_ON Breno Leitao
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