[powerpc][5.13.0-rc7] Kernel warning (kernel/sched/fair.c:401) while running LTP tests

[Sachin Sant]

>>> Any thoughts Vincent?
>> 
>> 
>> I would prefer that we use the reason of adding the cfs in the list instead.
>> 
>> Something like the below should also fixed the problem. It is based on a
>> proposal I made to Rik sometimes ago when he tried to flatten the rq:
>> https://lore.kernel.org/lkml/20190906191237.27006-6-riel@surriel.com/
>> 
>> This will ensure that a cfs is added in the list whenever one of its  child
>> is still in the list.
> 
> Could you confirm that this patch fixes the problem for you too ?
> 
Thanks for the fix.

The patch fixes the reported problem. The test ran to completion without
any failure. 

Reported-by: Sachin Sant <sachinp at linux.vnet.ibm.com>
Tested-by: Sachin Sant <sachinp at linux.vnet.ibm.com>

-Sachin