sched/core: Disable CONFIG_SCHED_CORE by default
This option at minimum adds extra code to the scheduler - even if
it's default unused - and most users wouldn't want it.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index bd7c414..5876e30 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -102,7 +102,6 @@
config SCHED_CORE
bool "Core Scheduling for SMT"
- default y
depends on SCHED_SMT
help
This option permits Core Scheduling, a means of coordinated task
@@ -115,7 +114,8 @@
- mitigation of some (not all) SMT side channels;
- limiting SMT interference to improve determinism and/or performance.
- SCHED_CORE is default enabled when SCHED_SMT is enabled -- when
- unused there should be no impact on performance.
+ SCHED_CORE is default disabled. When it is enabled and unused,
+ which is the likely usage by Linux distributions, there should
+ be no measurable impact on performance.