Re: [PATCH 2/5] io_uring: mark exit side kworkers as task_work capable

[Jens Axboe <axboe@kernel.dk>]

On 6/5/24 9:01 AM, Pavel Begunkov wrote:
>> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
>> index 96f6da0bf5cd..3ad915262a45 100644
>> --- a/io_uring/io_uring.c
>> +++ b/io_uring/io_uring.c
>> @@ -234,6 +234,20 @@ static inline void io_req_add_to_cache(struct io_kiocb *req, struct io_ring_ctx
>>       wq_stack_add_head(&req->comp_list, &ctx->submit_state.free_list);
>>   }
>>   +static __cold void io_kworker_tw_start(void)
>> +{
>> +    if (WARN_ON_ONCE(!(current->flags & PF_NO_TASKWORK)))
>> +        return;
>> +    current->flags &= ~PF_NO_TASKWORK;
>> +}
>> +
>> +static __cold void io_kworker_tw_end(void)
>> +{
>> +    while (task_work_pending(current))
>> +        task_work_run();
> 
> Clear TIF_NOTIFY_SIGNAL/RESUME? Maybe even retrying task_work_run()
> after and looping around if there are items to execute.

Yeah good point, it should handle clear the notifiers too. Will make
that change.

-- 
Jens Axboe