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Date:   Mon, 27 Mar 2023 17:36:33 -0700
From:   Dan Williams <dan.j.williams@intel.com>
To:     Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>,
        <io-uring@vger.kernel.org>, <linux-block@vger.kernel.org>
CC:     <linux-kernel@vger.kernel.org>,
        Miklos Szeredi <mszeredi@redhat.com>,
        ZiyangZhang <ZiyangZhang@linux.alibaba.com>,
        Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>,
        Bernd Schubert <bschubert@ddn.com>,
        Pavel Begunkov <asml.silence@gmail.com>,
        Stefan Hajnoczi <stefanha@redhat.com>,
        Ming Lei <ming.lei@redhat.com>
Subject: RE: [PATCH V4 00/17] io_uring/ublk: add IORING_OP_FUSED_CMD
Message-ID: <642236912a229_29cc2942c@dwillia2-xfh.jf.intel.com.notmuch>
References: <20230324135808.855245-1-ming.lei@redhat.com>
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Ming Lei wrote:
> Hello Jens,
> 
> Add IORING_OP_FUSED_CMD, it is one special URING_CMD, which has to
> be SQE128. The 1st SQE(master) is one 64byte URING_CMD, and the 2nd
> 64byte SQE(slave) is another normal 64byte OP. For any OP which needs
> to support slave OP, io_issue_defs[op].fused_slave needs to be set as 1,
> and its ->issue() can retrieve/import buffer from master request's
> fused_cmd_kbuf. The slave OP is actually submitted from kernel, part of
> this idea is from Xiaoguang's ublk ebpf patchset, but this patchset
> submits slave OP just like normal OP issued from userspace, that said,
> SQE order is kept, and batching handling is done too.

Hi Ming,

io_uring and ublk are starting to be more on my radar these days. I
wanted to take a look at this series, but could not get past the
distracting "master"/"slave" terminology in this lead-in paragraph let
alone start looking at patches.

Frankly, the description sounds more like "head"/"tail", or even
"fuse0"/"fuse1" because, for example, who is to say you might not have
larger fused ops in the future and need terminology to address
"fuse{0,1,2,3}"?

Once that's fixed up I can take a look at forwarding on to others that
might be interested in this use case.

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst#n338

Thanks in advance for fixing that up!