tree 5411af06d52a3f567e6b3fe592128d3fc0306be1
parent c3ce910b1456a45fa88959af3735bd6b285e54af
author Paul E. McKenney <paul.mckenney@linaro.org> 1329458373 -0800
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1329846150 -0800

rcu: Hold off RCU_FAST_NO_HZ after timer posted

This commit handles workloads that transition quickly between idle and
non-idle, and where the CPU's callbacks cannot be invoked, but where
RCU does not have anything immediate for the CPU to do.  Without this
patch, the RCU_FAST_NO_HZ code can be invoked repeatedly on each entry
to idle.  The commit sets the per-CPU rcu_dyntick_holdoff variable to
hold off further attempts for a tick.

Reported-by: "Abou Gazala, Neven M" <neven.m.abou.gazala@intel.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>