Re: [PATCH v2 liburing] add helper functions to verify io_uring functionality

Glauber Costa
2020-01-30T16:29:38Z

On Thu, Jan 30, 2020 at 11:13 AM Jens Axboe <axboe@kernel.dk> wrote:
>
> On 1/30/20 9:00 AM, Glauber Costa wrote:
> > It is common for an application using an ever-evolving interface to want
> > to inquire about the presence of certain functionality it plans to use.
> >
> > Information about opcodes is stored in a io_uring_probe structure. There
> > is usually some boilerplate involved in initializing one, and then using
> > it to check if it is enabled.
> >
> > This patch adds two new helper functions: one that returns a pointer to
> > a io_uring_probe (or null if it probe is not available), and another one
> > that given a probe checks if the opcode is supported.
>
> This looks good, I committed it with minor changes.
>
> On top of this, we should have a helper that doesn't need a ring. So
> basically one that just sets up a ring, calls io_uring_get_probe(),
> then tears down the ring.
>
I'd be happy to follow up with that.

Just to be sure, the information returned by probe should be able to outlive the
tear down of the ring, right ?