Re: [PATCH v5 2/3] io_uring: add api to set / get napi configuration.

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

On 11/22/22 2:14 AM, Stefan Roesch wrote:
> +static int io_unregister_napi(struct io_ring_ctx *ctx, void __user *arg)
> +{
> +#ifdef CONFIG_NET_RX_BUSY_POLL
> +	const struct io_uring_napi curr = {
> +		.busy_poll_to = ctx->napi_busy_poll_to,
> +	};
> +
> +	if (copy_to_user(arg, &curr, sizeof(curr)))
> +		return -EFAULT;
> +
> +	WRITE_ONCE(ctx->napi_busy_poll_to, 0);
> +	return 0;
> +#else
> +	return -EINVAL;
> +#endif
> +}
> +
I suggest allowing users to pass a NULL as the arg in case they
don't want to care about the old values.

Something like:

    io_uring_unregister_napi(ring, NULL);

What do you think?

-- 
Ammar Faizi