Use kernel/Kconfig.preempt for ARM
before this patch ARM had it's own definition of CONFIG_PREEMPT.
Instead of that use the general definition provided in
kernel/Kconfig.preempt.
This patch changes the available options in *config. Namely PREEMPT
isn't a stand alone bool anymore, but part of a 'choice' the
following Kconfig symbols are added:
PREEMPT_NONE
PREEMPT_VOLUNTARY
Selecting PREEMPT_NONE now produces exactly the code as not selecting
PREEMPT before (apart from a comment in
/sys/kernel/debug/tracing/(per_cpu/cpuX/)?trace). The only difference
PREEMPT_VOLUNTARY does is that might_resched might reschedule. Both
should't introduce regressions.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index aef63c8..eac1a92 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -962,18 +962,7 @@
accounting to be spread across the timer interval, preventing a
"thundering herd" at every timer tick.
-config PREEMPT
- bool "Preemptible Kernel (EXPERIMENTAL)"
- depends on EXPERIMENTAL
- help
- This option reduces the latency of the kernel when reacting to
- real-time or interactive events by allowing a low priority process to
- be preempted even if it is in kernel mode executing a system call.
- This allows applications to run more reliably even when the system is
- under load.
-
- Say Y here if you are building a kernel for a desktop, embedded
- or real-time system. Say N if you are unsure.
+source kernel/Kconfig.preempt
config HZ
int