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

[Gabriel Krisman Bertazi <krisman@suse.de>]

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>


-- 
Gabriel Krisman Bertazi