hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I50PPU
CVE: NA

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when unthrottle a cfs_rq at distribute_cfs_runtime(), another cpu
may re-throttle this cfs_rq at qos_throttle_cfs_rq() before access
the cfs_rq->throttle_list.next, but meanwhile, qos throttle will
attach the cfs_rq throttle_list node to percpu qos_throttled_cfs_rq,
it will change cfs_rq->throttle_list.next and cause panic or hardlockup
at distribute_cfs_runtime().

Fix it by adding a qos_throttle_list node in struct cfs_rq, and qos
throttle disuse the cfs_rq->throttle_list.
Signed-off-by: NZhang Qiao <zhangqiao22@huawei.com>
Reviewed-by: Nzheng zucheng <zhengzucheng@huawei.com>
Reviewed-by: NChen Hui <judy.chenhui@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>