[PATCH 2/3] sched/isolation: Enable CONFIG_CPU_ISOLATION=y by default

From: Frederic Weisbecker
Date: Thu Dec 14 2017 - 13:19:00 EST


The "isolcpus=" boot parameter support was always built-in before we
moved the related code under CONFIG_CPU_ISOLATION. Having it disabled by
default is very confusing for people accustomed to use this parameter.

So enable it by dafault to keep the previous behaviour but keep it
optable for those who want to tinify their kernels.

Signed-off-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Chris Metcalf <cmetcalf@xxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Luiz Capitulino <lcapitulino@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Wanpeng Li <kernellwp@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
---
init/Kconfig | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/init/Kconfig b/init/Kconfig
index 2934249..690a381 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -461,10 +461,14 @@ endmenu # "CPU/Task time and stats accounting"

config CPU_ISOLATION
bool "CPU isolation"
+ default y
help
Make sure that CPUs running critical tasks are not disturbed by
any source of "noise" such as unbound workqueues, timers, kthreads...
- Unbound jobs get offloaded to housekeeping CPUs.
+ Unbound jobs get offloaded to housekeeping CPUs. This is driven by
+ the "isolcpus=" boot parameter.
+
+ Say Y if unsure.

source "kernel/rcu/Kconfig"

--
2.7.4