nohz_full: Add Kconfig parameter for scalable detection of all-idle state
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Fri, 21 Jun 2013 18:08:45 +0000 (11:08 -0700)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Mon, 19 Aug 2013 01:07:02 +0000 (18:07 -0700)
commitb44379af1cf40050794832c38ea6a64e07eb5087
tree2f7fb3764976a4a0e2d2cf7a7f814564361203a4
parent8bdf7a252b6398dbd4beaa7a2ba0904cea0abd04
nohz_full: Add Kconfig parameter for scalable detection of all-idle state

At least one CPU must keep the scheduling-clock tick running for
timekeeping purposes whenever there is a non-idle CPU.  However, with
the new nohz_full adaptive-idle machinery, it is difficult to distinguish
between all CPUs really being idle as opposed to all non-idle CPUs being
in adaptive-ticks mode.  This commit therefore adds a Kconfig parameter
as a first step towards enabling a scalable detection of full-system
idle state.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
[ paulmck: Update help text per Frederic Weisbecker. ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
kernel/time/Kconfig