Re: [PATCH 1/2] io_uring: switch struct io_ring_ctx internal bitfields to flags

[Jens Axboe <axboe@kernel.dk>]

On 3/16/26 2:34 PM, Gabriel Krisman Bertazi wrote:
> Jens Axboe <axboe@kernel.dk> writes:
> 
>> On 3/14/26 9:16 PM, Gabriel Krisman Bertazi wrote:
>>
>>> Jens Axboe <axboe@kernel.dk> writes:
>>>
>>>> Bitfields cannot be set and checked atomically, and this makes it more
>>>> clear that these are indeed in shared storage and must be checked and
>>>> set in a sane fashion. This is in preparation for annotating a few of
>>>> the known racy, but harmless, flags checking.
>>>>
>>>> No intended functional changes in this patch.
>>>>
>>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>>>> ---
>>>>  include/linux/io_uring_types.h | 32 +++++++------
>>>>  io_uring/eventfd.c             |  4 +-
>>>>  io_uring/io_uring.c            | 82 +++++++++++++++++-----------------
>>>>  io_uring/io_uring.h            |  9 ++--
>>>>  io_uring/msg_ring.c            |  2 +-
>>>>  io_uring/register.c            |  8 ++--
>>>>  io_uring/rsrc.c                |  8 ++--
>>>>  io_uring/tctx.c                |  2 +-
>>>>  io_uring/timeout.c             |  4 +-
>>>>  io_uring/tw.c                  |  2 +-
>>>>  10 files changed, 80 insertions(+), 73 deletions(-)
>>>>
>>>> diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
>>>> index dd1420bfcb73..b84576374c7b 100644
>>>> --- a/include/linux/io_uring_types.h
>>>> +++ b/include/linux/io_uring_types.h
>>>> @@ -268,24 +268,28 @@ struct io_alloc_cache {
>>>>  	unsigned int		init_clear;
>>>>  };
>>>>  
>>>> +enum {
>>>> +	IO_RING_F_DRAIN_NEXT		= BIT(0),
>>>> +	IO_RING_F_OP_RESTRICTED		= BIT(1),
>>>> +	IO_RING_F_REG_RESTRICTED	= BIT(2),
>>>> +	IO_RING_F_OFF_TIMEOUT_USED	= BIT(3),
>>>> +	IO_RING_F_DRAIN_ACTIVE		= BIT(4),
>>>> +	IO_RING_F_HAS_EVFD		= BIT(5),
>>>> +	/* all CQEs should be posted only by the submitter task */
>>>> +	IO_RING_F_TASK_COMPLETE		= BIT(6),
>>>> +	IO_RING_F_LOCKLESS_CQ		= BIT(7),
>>>> +	IO_RING_F_SYSCALL_IOPOLL	= BIT(8),
>>>> +	IO_RING_F_POLL_ACTIVATED	= BIT(9),
>>>> +	IO_RING_F_DRAIN_DISABLED	= BIT(10),
>>>> +	IO_RING_F_COMPAT		= BIT(11),
>>>> +	IO_RING_F_IOWQ_LIMITS_SET	= BIT(12),
>>>> +};
>>>> +
>>>>  struct io_ring_ctx {
>>>>  	/* const or read-mostly hot data */
>>>>  	struct {
>>>>  		unsigned int		flags;
>>>> -		unsigned int		drain_next: 1;
>>>> -		unsigned int		op_restricted: 1;
>>>> -		unsigned int		reg_restricted: 1;
>>>> -		unsigned int		off_timeout_used: 1;
>>>> -		unsigned int		drain_active: 1;
>>>> -		unsigned int		has_evfd: 1;
>>>> -		/* all CQEs should be posted only by the submitter task */
>>>> -		unsigned int		task_complete: 1;
>>>> -		unsigned int		lockless_cq: 1;
>>>> -		unsigned int		syscall_iopoll: 1;
>>>> -		unsigned int		poll_activated: 1;
>>>> -		unsigned int		drain_disabled: 1;
>>>> -		unsigned int		compat: 1;
>>>> -		unsigned int		iowq_limits_set : 1;
>>>> +		unsigned int		int_flags;
>>>
>>> Jens,
>>>
>>> What does the int prefix means in this context?
>>
>> It's just short for 'internal'.
> 
> ack.  Perhaps a comment indicating this is internal would be
> useful. Otherwise,
> 
> Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>

Added the comment and your reviewed-by, thanks!

-- 
Jens Axboe