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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-10-07 09:26:13 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-10-23 14:54:07 -0700 |
| commit | ba49df4767d4fa5bbd2af3a51709fb81f94264ec (patch) | |
| tree | 5fe4594735aff61cb4b6b9f53885f35e3e05a415 /init | |
| parent | 4d9a5d4319e22670ec6d6227e12b54f361c46d0f (diff) | |
| download | linux-ba49df4767d4fa5bbd2af3a51709fb81f94264ec.tar.gz linux-ba49df4767d4fa5bbd2af3a51709fb81f94264ec.tar.bz2 linux-ba49df4767d4fa5bbd2af3a51709fb81f94264ec.zip | |
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 <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/init/Kconfig b/init/Kconfig index 6fdd6e339326..b63e7982c1c6 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -582,14 +582,13 @@ config RCU_FAST_NO_HZ depends on NO_HZ && SMP default n help - 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. |