CC: [email protected]
TO: Peter Zijlstra <[email protected]>
CC: Julien Desfossez <[email protected]>
CC: "Joel Fernandes (Google)" <[email protected]>
CC: Vineeth Remanan Pillai <[email protected]>

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git 
sched/core-sched
head:   ead81f232b5b31ab6240a719ff3bad564c3f0e4c
commit: 9dd19f8a1f0afa94e4238793bd74dc6b8aae718e [1/11] sched: Wrap rq::lock 
access
:::::: branch date: 35 hours ago
:::::: commit date: 35 hours ago
config: openrisc-randconfig-m031-20210108 (attached as .config)
compiler: or1k-linux-gcc (GCC) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>

smatch warnings:
kernel/sched/sched.h:2206 _double_lock_balance() warn: inconsistent returns 
'*rq_lockp(busiest)'.
kernel/sched/sched.h:2206 _double_lock_balance() warn: inconsistent returns 
'*rq_lockp(busiest)'.

vim +2206 kernel/sched/sched.h

029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2177  
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2178  #else
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2179  /*
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2180   * Unfair 
double_lock_balance: Optimizes throughput at the expense of
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2181   * 
latency by eliminating extra atomic operations when the locks are
97fb7a0a8944bd6 kernel/sched/sched.h Ingo Molnar    2018-03-03  2182   * 
already in proper order on entry.  This favors lower CPU-ids and will
97fb7a0a8944bd6 kernel/sched/sched.h Ingo Molnar    2018-03-03  2183   * grant 
the double lock to lower CPUs over higher ids under contention,
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2184   * 
regardless of entry order into the function.
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2185   */
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2186  static 
inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2187    
__releases(this_rq->lock)
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2188    
__acquires(busiest->lock)
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2189    
__acquires(this_rq->lock)
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2190  {
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2191    if 
(rq_lockp(this_rq) == rq_lockp(busiest))
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2192            
return 0;
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2193  
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2194    if 
(likely(raw_spin_trylock(rq_lockp(busiest))))
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2195            
return 0;
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2196  
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2197    if 
(rq_lockp(busiest) >= rq_lockp(this_rq)) {
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2198            
raw_spin_lock_nested(rq_lockp(busiest), SINGLE_DEPTH_NESTING);
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2199            
return 0;
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2200    }
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2201  
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2202    
raw_spin_unlock(rq_lockp(this_rq));
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2203    
raw_spin_lock(rq_lockp(busiest));
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2204    
raw_spin_lock_nested(rq_lockp(this_rq), SINGLE_DEPTH_NESTING);
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17  2205  
9dd19f8a1f0afa9 kernel/sched/sched.h Peter Zijlstra 2020-11-17 @2206    return 
1;
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2207  }
029632fbb7b7c9d kernel/sched.h       Peter Zijlstra 2011-10-25  2208  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]

Attachment: .config.gz
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