Re: [PATCH] loop: inherit the ioprio in loop woker thread

[Jens Axboe <axboe@kernel.dk>]

On 5/22/24 11:38 AM, Bart Van Assche wrote:
> On 5/22/24 00:48, Yunlong Xing wrote:
>> @@ -1913,6 +1921,10 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
>>           set_active_memcg(old_memcg);
>>           css_put(cmd_memcg_css);
>>       }
>> +
>> +    if (ori_ioprio != cmd_ioprio)
>> +        set_task_ioprio(current, ori_ioprio);
>> +
>>    failed:
>>       /* complete non-aio request */
>>       if (!use_aio || ret) {
> 
> Does adding this call in the hot path have a measurable performance impact?

It's loop, I would not be concerned with overhead. But it does look pretty
bogus to modify the task ioprio from here.

-- 
Jens Axboe