Re: [PATCH v1 0/2] Add timeout mechanism to qmp actions

[Paolo Bonzini]

On 19/10/20 14:40, Zhenyu Ye wrote:
> The kernel backtrace for io_submit in GUEST is:
> 
>       guest# ./offcputime -K -p `pgrep -nx fio`
>           b'finish_task_switch'
>           b'__schedule'
>           b'schedule'
>           b'io_schedule'
>           b'blk_mq_get_tag'
>           b'blk_mq_get_request'
>           b'blk_mq_make_request'
>           b'generic_make_request'
>           b'submit_bio'
>           b'blkdev_direct_IO'
>           b'generic_file_read_iter'
>           b'aio_read'
>           b'io_submit_one'
>           b'__x64_sys_io_submit'
>           b'do_syscall_64'
>           b'entry_SYSCALL_64_after_hwframe'
>           -                fio (1464)
>               40031912
> 
> And Linux io_uring can avoid the latency problem.

What filesystem are you using?

Paolo