rcu: Simplify quiescent-state detection
authorPaul E. McKenney <paul.mckenney@linaro.org>
Tue, 21 Aug 2012 22:00:05 +0000 (15:00 -0700)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Sun, 23 Sep 2012 14:41:56 +0000 (07:41 -0700)
commitd7d6a11e8609f0319d4a2d8ede348f8b3374b652
tree64a2e3260690a85fe637a3e34c94e8ca540e8fc6
parent1943c89de700248d68385300a9b5588a1e314f90
rcu: Simplify quiescent-state detection

The current quiescent-state detection algorithm is needlessly
complex.  It records the grace-period number corresponding to
the quiescent state at the time of the quiescent state, which
works, but it seems better to simply erase any record of previous
quiescent states at the time that the CPU notices the new grace
period.  This has the further advantage of removing another piece
of RCU for which lockless reasoning is required.

Therefore, this commit makes this change.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
kernel/rcutree.c
kernel/rcutree.h
kernel/rcutree_plugin.h
kernel/rcutree_trace.c