Re: [PATCH V3 02/16] io_uring: add IORING_OP_FUSED_CMD

[Ming Lei <ming.lei@redhat.com>]

On Sat, Mar 18, 2023 at 11:24:07PM +0800, Ming Lei wrote:
> On Sat, Mar 18, 2023 at 08:31:44AM -0600, Jens Axboe wrote:
> > On 3/14/23 6:57?AM, Ming Lei wrote:
> > > 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 has to be set as 1,
> > > and its ->issue() needs to retrieve buffer from master request's
> > > fused_cmd_kbuf.
> > 
> > Since we'd be introducing this as a new concept, probably makes sense to
> > name it something other than master/slave. What about primary and
> > secondary? Producer/consumer?
> 
> Either of the two looks fine for me, and I will take secondary in next
> version if no one objects.

Thinking of further, probably master/slave is still better since slave
OP can be thought as part of master command, and it does serve for
master command.

That said master command not only provides buffer reference to slave OP,
but also requires slave OP to consume the buffer reference and complete the OP.

> > How about _bvec_buf_ or simply _buf_?

> Either one is fine, buf probably good enough and makes it a bit shorter.

OK.


Thanks, 
Ming