rcu: Permit RCU_FAST_NO_HZ to be used by TREE_PREEMPT_RCU

The new implementation of RCU_FAST_NO_HZ is compatible with preemptible
RCU, so this commit removes the Kconfig restriction that previously
prohibited this.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit is contained in:
Paul E. McKenney 2011-11-03 14:56:12 -07:00 committed by Paul E. McKenney
parent 11dbaa8cb7
commit b807fbff31
1 changed files with 5 additions and 5 deletions

View File

@ -469,14 +469,14 @@ config RCU_FANOUT_EXACT
config RCU_FAST_NO_HZ
bool "Accelerate last non-dyntick-idle CPU's grace periods"
depends on TREE_RCU && NO_HZ && SMP
depends on NO_HZ && SMP
default n
help
This option causes RCU to attempt to accelerate grace periods
in order to allow the final CPU to enter dynticks-idle state
more quickly. On the other hand, this option increases the
overhead of the dynticks-idle checking, particularly on systems
with large numbers of CPUs.
in order to allow CPUs to enter dynticks-idle state more
quickly. On the other hand, this option increases the overhead
of the dynticks-idle checking, particularly on systems with
large numbers of CPUs.
Say Y if energy efficiency is critically important, particularly
if you have relatively few CPUs.