locktorture: Print ratio of acquisitions, not failures
authorPaul E. McKenney <paulmck@kernel.org>
Thu, 23 Jan 2020 17:19:01 +0000 (09:19 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 23 Apr 2020 08:36:44 +0000 (10:36 +0200)
commit0c72ec11d8bd54975266ea09d1f65160fadd2f4c
treed3417a633ccd7fb36cbb67a219cfb60851316fca
parent01c9e2a9fc5ce7f0ce0e692aaf0c57fbaf224bfc
locktorture: Print ratio of acquisitions, not failures

commit 80c503e0e68fbe271680ab48f0fe29bc034b01b7 upstream.

The __torture_print_stats() function in locktorture.c carefully
initializes local variable "min" to statp[0].n_lock_acquired, but
then compares it to statp[i].n_lock_fail.  Given that the .n_lock_fail
field should normally be zero, and given the initialization, it seems
reasonable to display the maximum and minimum number acquisitions
instead of miscomputing the maximum and minimum number of failures.
This commit therefore switches from failures to acquisitions.

And this turns out to be not only a day-zero bug, but entirely my
own fault.  I hate it when that happens!

Fixes: 0af3fe1efa53 ("locktorture: Add a lock-torture kernel module")
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/locking/locktorture.c