Re: [RFC PATCH v4 2/3] io_uring: add api to set / get napi configuration.

[Stefan Roesch <shr@devkernel.io>]

Jens Axboe <axboe@kernel.dk> writes:

> On 11/21/22 10:29 AM, Stefan Roesch wrote:
>> This adds an api to register the busy poll timeout from liburing. To be
>> able to use this functionality, the corresponding liburing patch is needed.
>>
>> Signed-off-by: Stefan Roesch <shr@devkernel.io>
>> ---
>>  include/linux/io_uring_types.h |  2 +-
>>  include/uapi/linux/io_uring.h  | 11 +++++++
>>  io_uring/io_uring.c            | 54 ++++++++++++++++++++++++++++++++++
>>  3 files changed, 66 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
>> index 23993b5d3186..67b861305d97 100644
>> --- a/include/linux/io_uring_types.h
>> +++ b/include/linux/io_uring_types.h
>> @@ -274,8 +274,8 @@ struct io_ring_ctx {
>>  	struct list_head	napi_list;	/* track busy poll napi_id */
>>  	spinlock_t		napi_lock;	/* napi_list lock */
>>
>> -	unsigned int		napi_busy_poll_to; /* napi busy poll default timeout */
>>  	bool			napi_prefer_busy_poll;
>> +	unsigned int		napi_busy_poll_to;
>>  #endif
>
> Why is this being moved? Seems unrelated, and it actually creates another
> hole rather than filling one as it did before.

That was not intended. The next version of the patch will restore the
previous order.