On Mon, Nov 19, 2018 at 12:51:27PM +0900, Damien Le Moal wrote: > As explained in ioprio_get() and ionice man pages, the default I/O > priority class for processes which have not set an I/O priority using > ioprio_set() is IOPRIO_CLASS_BE and not IOPRIO_CLASS_NONE. While this matches the documentation, we've returned the current values for 10 years, and before that plain 0 without any ioprio magic. It might be safer to just fix the documentation.