tree 171b04df7e3266fb59fd6dc117d7ae07440c3caf
parent 66e1e18133c43e0cfff609054aa64ad0652371fa
author Chris Wilson <chris@chris-wilson.co.uk> 1595703070 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1599125061 +0200

locking/lockdep: Fix overflow in presentation of average lock-time

[ Upstream commit a7ef9b28aa8d72a1656fa6f0a01bbd1493886317 ]

Though the number of lock-acquisitions is tracked as unsigned long, this
is passed as the divisor to div_s64() which interprets it as a s32,
giving nonsense values with more than 2 billion acquisitons. E.g.

  acquisitions   holdtime-min   holdtime-max holdtime-total   holdtime-avg
  -------------------------------------------------------------------------
    2350439395           0.07         353.38   649647067.36          0.-32

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200725185110.11588-1-chris@chris-wilson.co.uk
Signed-off-by: Sasha Levin <sashal@kernel.org>