tree 08cae2878e46409d6f5cffd0d37499bfa4851abc
parent 0edd1b1784cbdad55aca2c1293be018f53c0ab1d
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1371859840 -0700
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1377985442 -0700

nohz_full: Force RCU's grace-period kthreads onto timekeeping CPU

Because RCU's quiescent-state-forcing mechanism is used to drive the
full-system-idle state machine, and because this mechanism is executed
by RCU's grace-period kthreads, this commit forces these kthreads to
run on the timekeeping CPU (tick_do_timer_cpu).  To do otherwise would
mean that the RCU grace-period kthreads would force the system into
non-idle state every time they drove the state machine, which would
be just a bit on the futile side.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>