|author||Paul E. McKenney <firstname.lastname@example.org>||2012-10-07 09:26:13 -0700|
|committer||Paul E. McKenney <email@example.com>||2012-10-23 14:54:07 -0700|
|parent||rcu: Remove rcu_switch() (diff)|
rcu: Update RCU_FAST_NO_HZ help text
The RCU_FAST_NO_HZ help text included a warning about overhead on large systems, but that issue has since been resolved. The main remaining issue with RCU_FAST_NO_HZ is increased real-time latency. This commit therefore updates the help text accordingly. Signed-off-by: Paul E. McKenney <firstname.lastname@example.org> Signed-off-by: Paul E. McKenney <email@example.com>
1 files changed, 7 insertions, 8 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 6fdd6e339326..b63e7982c1c6 100644
@@ -582,14 +582,13 @@ config RCU_FAST_NO_HZ
depends on NO_HZ && SMP
- This option causes RCU to attempt to accelerate grace periods
- 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.
+ This option causes RCU to attempt to accelerate grace periods 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, thus degrading scheduling latency.
+ Say Y if energy efficiency is critically important, and you don't
+ care about real-time response.
Say N if you are unsure.