为什么提交这份PR (why to submit this PR)
Issue: using iperf server with sshd together and the kernel will get stuck occasionally.
taken_list is accessed from other mutex when updating priority.
你的解决方案是什么 (what is your solution)
protect taken_list on shared lock, but not on mutex local spinlock.
Signed-off-by: Shell <smokewood@qq.com>