this behaviour is explicitly specified here: https://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_08.html and map SCHED_NORMAL to SCHED_OTHER like Linux: https://man7.org/linux/man-pages/man7/sched.7.html Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>