rcutorture: Use monotonic timestamp for stall detection
authorArnd Bergmann <arnd@arndb.de>
Mon, 18 Jun 2018 14:47:34 +0000 (16:47 +0200)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Thu, 12 Jul 2018 22:42:07 +0000 (15:42 -0700)
commit622be33fcbc93e9b672b99ed338369eb5e843ac3
tree32387c744ccb51339aa8c2dc1220d0d85ecba360
parent3b745c8969c752601cb68c82a06735363563ab42
rcutorture: Use monotonic timestamp for stall detection

The get_seconds() call is deprecated because it overflows on 32-bit
architectures. The algorithm in rcu_torture_stall() can deal with
the overflow, but another problem here is that using a CLOCK_REALTIME
stamp can lead to a false-positive stall warning when a settimeofday()
happens concurrently.

Using ktime_get_seconds() instead avoids those issues and will never
overflow. The added cast to 'unsigned long' however is necessary to
make ULONG_CMP_LT() work correctly.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
kernel/rcu/rcutorture.c