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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2005-06-25 20:39:45 +0200
committerRussell King <rmk+kernel@arm.linux.org.uk>2005-06-25 20:39:45 +0200
commit8749af68216e1ebf6460992fce548f400ecf63a4 (patch)
tree6968809c357c1cf8167208f480f0e974bf9af955 /arch/arm/Kconfig
parent[PATCH] ARM: 2752/1: disable ixp2000 PCI I/O software workaround on chips tha... (diff)
downloadlinux-8749af68216e1ebf6460992fce548f400ecf63a4.tar.xz
linux-8749af68216e1ebf6460992fce548f400ecf63a4.zip
[PATCH] ARM: Generic Dynamic Tick Timer support for ARM, take 4
This patch adds support for Dynamic Tick Timer for ARM. Dynamic Tick is also known as VST (Variable Scheduling Timeouts). Dynamic Tick has been in use in the OMAP tree since last October. The patch is not intrusive, and does not do anything unless CONFIG_NO_IDLE_HZ is defined. This patch has the following fixed based on comments from RMK: - Time is updated before calling interrupt handlers. - Added new interrupt flag SA_TIMER to avoid duplicate timer interrupts - Moved struct dyn_tick_timer to time.h until we at some point probably have an arch independent dyn-tick.h - Cleaned up testing for DYN_TICK_ENABLED in irq.c I've cleaned up this patch to fix some remaining issues: - Call the timer tick handler with irqs disabled, as it would be from a normal interrupt - if we have a dyn_tick, we better implement all methods. - generic timer_dyn_reprogram() call, to be called before sleeping - added command line option - "dyntick=" to allow boot-time control of this feature -- rmk Signed-off-by: Tony Lindgren Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/Kconfig')
-rw-r--r--arch/arm/Kconfig15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index bfcf42280368..c8d94dcd8ef7 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -346,6 +346,21 @@ config PREEMPT
Say Y here if you are building a kernel for a desktop, embedded
or real-time system. Say N if you are unsure.
+config NO_IDLE_HZ
+ bool "Dynamic tick timer"
+ help
+ Select this option if you want to disable continuous timer ticks
+ and have them programmed to occur as required. This option saves
+ power as the system can remain in idle state for longer.
+
+ By default dynamic tick is disabled during the boot, and can be
+ manually enabled with:
+
+ echo 1 > /sys/devices/system/timer/timer0/dyn_tick
+
+ Alternatively, if you want dynamic tick automatically enabled
+ during boot, pass "dyntick=enable" via the kernel command string.
+
config ARCH_DISCONTIGMEM_ENABLE
bool
default (ARCH_LH7A40X && !LH7A40X_CONTIGMEM)