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

From: Stefan Roesch <[email-masked]>
Date: Mon, 28 Nov 2022 12:22:19 -0800

Ammar Faizi <[email-masked]> writes:

> 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?

Sounds good, i can make that change in the next version.