rcu: Make rcu_seq_diff() more exact
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Sat, 9 Jun 2018 08:22:20 +0000 (01:22 -0700)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Thu, 12 Jul 2018 22:39:23 +0000 (15:39 -0700)
commit2ee5aca54622aacc196106c623fea4116f1043a6
treef364e3a66f8715e2b39035a4d86724f27e3199b0
parent264d4f88ad5ba0d3c890a70a1216b4e87e5c26ec
rcu: Make rcu_seq_diff() more exact

The current implementatation of rcu_seq_diff() follows tradition in
providing a rough-and-ready approximation of the number of elapsed grace
periods between the two rcu_seq values.  However, this difference is
used to flag RCU-failure "near misses", which can be a valuable debugging
aid, so more exactitude would be an improvement.  This commit therefore
improves the accuracy of rcu_seq_diff().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
kernel/rcu/rcu.h