Commit 9fc52d83 authored Jan 08, 2013 by Paul E. McKenney

rcu: Allow TREE_PREEMPT_RCU on UP systems



The TINY_PREEMPT_RCU is complex, does not provide that much memory
savings, and therefore TREE_PREEMPT_RCU should be used instead.  The
systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU
are quite small compared to the memory footprint of CONFIG_PREEMPT.

This commit therefore takes a first step towards eliminating
TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP
systems.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

parent 6bfc09e2

init/Kconfig

+3 −1

Original line number	Diff line number	Diff line
		@@ -453,7 +453,7 @@ config TREE_RCU

		config TREE_PREEMPT_RCU
		bool "Preemptible tree-based hierarchical RCU"
		depends on PREEMPT && SMP
		depends on PREEMPT
		help
		This option selects the RCU implementation that is
		designed for very large SMP systems with hundreds or
		@@ -461,6 +461,8 @@ config TREE_PREEMPT_RCU
		is also required. It also scales down nicely to
		smaller systems.

		Select this option if you are unsure.

		config TINY_RCU
		bool "UP-only small-memory-footprint RCU"
		depends on !PREEMPT && !SMP