Re: [PATCH v9 1/4] liburing: add api to set napi busy poll settings

[Olivier Langlois <olivier@trillion01.com>]

On Fri, 2024-02-02 at 10:48 -0700, Jens Axboe wrote:
> On Feb 2, 2024, at 10:41 AM, Olivier Langlois
> <olivier@trillion01.com> wrote:
> > 
> > On Fri, 2024-02-02 at 09:42 -0700, Jens Axboe wrote:
> > > > On 2/2/24 9:41 AM, Olivier Langlois wrote:
> > > > On Tue, 2023-04-25 at 11:20 -0700, Stefan Roesch wrote:
> > > > > +
> > > > > +int io_uring_register_napi(struct io_uring *ring, struct
> > > > > io_uring_napi *napi)
> > > > > +{
> > > > > +    return __sys_io_uring_register(ring->ring_fd,
> > > > > +                IORING_REGISTER_NAPI, napi, 0);
> > > > > +}
> > > > > +
> > > > > +int io_uring_unregister_napi(struct io_uring *ring, struct
> > > > > io_uring_napi *napi)
> > > > > +{
> > > > > +    return __sys_io_uring_register(ring->ring_fd,
> > > > > +                IORING_UNREGISTER_NAPI, napi,
> > > > > 0);
> > > > > +}
> > > > 
> > > > my apologies if this is not the latest version of the patch but
> > > > I
> > > > think
> > > > that it is...
> > > > 
> > > > nr_args should be 1 to match what __io_uring_register() in the
> > > > current
> > > > corresponding kernel patch expects:
> > > > 
> > > > https://git.kernel.dk/cgit/linux/commit/?h=io_uring-napi&id=787d81d3132aaf4eb4a4a5f24ff949e350e537d0
> > > 
> > > Can you send a patch I can fold in?
> > > 
> > Jens,
> > 
> > I am unsure of what you are asking me.
> > 
> > You would like me to send a patch to fix a liburing patch that has
> > never been applied AFAIK?
> > 
> > if the v9 patch has never been applied. Wouldn't just editing
> > Stefan
> > patch by replacing the nr_args param from 0 to 1 directly do it?
> 
> The current version is what is in that branch you referenced. If you
> see anything in there that needs changing, send a patch for that. 
> 
> I can send out the series again if needed.
> 
AFAIK, the kernel patch is fine.

my comment was referring the liburing patch that is calling
__sys_io_uring_register() by passing a nr_args value of 0.

This is problematic because on the kernel side, io_uring_register()
returns -EINVAL if nr_args is not 1.