[PATCH 07/16] kconfig-dynamic-frequency.diff

Jan Engelhardt
2007-04-01T18:17:31Z

Make HZ fully configurable through menuconfig.

Already posted at http://lkml.org/lkml/2006/6/18/111

Signed-off-by: Jan Engelhardt
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> (http://lkml.org/lkml/2006/11/8/307)
Cc: Sam Ravnborg <sam@ravnborg.org>

Kconfig.hz | 70 +++++++++++++++++++++++--------------------------------------
1 file changed, 27 insertions(+), 43 deletions(-)

Index: linux-2.6.21-rc5/kernel/Kconfig.hz
===================================================================
--- linux-2.6.21-rc5.orig/kernel/Kconfig.hz
+++ linux-2.6.21-rc5/kernel/Kconfig.hz
@@ -2,50 +2,34 @@
# Timer Interrupt Frequency Configuration
#

-choice
- prompt "Timer frequency"
- default HZ_250
- help
- Allows the configuration of the timer frequency. It is customary
- to have the timer interrupt run at 1000 Hz but 100 Hz may be more
- beneficial for servers and NUMA systems that do not need to have
- a fast response for user interaction and that may experience bus
- contention and cacheline bounces as a result of timer interrupts.
- Note that the timer interrupt occurs on each processor in an SMP
- environment leading to NR_CPUS * HZ number of timer interrupts
- per second.
-
-
- config HZ_100
- bool "100 HZ"
- help
- 100 Hz is a typical choice for servers, SMP and NUMA systems
- with lots of processors that may show reduced performance if
- too many timer interrupts are occurring.
-
- config HZ_250
- bool "250 HZ"
- help
- 250 Hz is a good compromise choice allowing server performance
- while also showing good interactive responsiveness even
- on SMP and NUMA systems. If you are going to be using NTSC video
- or multimedia, selected 300Hz instead.
-
- config HZ_300
- bool "300 HZ"
- help
- 300 Hz is a good compromise choice allowing server performance
- while also showing good interactive responsiveness even
- on SMP and NUMA systems and exactly dividing by both PAL and
- NTSC frame rates for video and multimedia work.
-
- config HZ_1000
- bool "1000 HZ"
- help
- 1000 Hz is the preferred choice for desktop systems and other
- systems requiring fast interactive responses to events.
+config HZ
+ int "Timer frequency"
+ default 100
+ ---help---
+ Allows the configuration of the timer frequency. It is customary
+ to have the timer interrupt run at 1000 Hz but 100 Hz may be more
+ beneficial for servers and NUMA systems that do not need to have
+ a fast response for user interaction and that may experience bus
+ contention and cacheline bounces as a result of timer interrupts.
+ Note that the timer interrupt occurs on each processor in an SMP
+ environment leading to NR_CPUS * HZ number of timer interrupts
+ per second.
+
+ 100 Hz is a typical choice for servers, SMP and NUMA systems
+ with lots of processors that may show reduced performance if
+ too many timer interrupts are occurring.
+
+ 250 Hz is a good compromise choice allowing server performance
+ while also showing good interactive responsiveness even on SMP
+ and NUMA systems.
+
+ 300 Hz is a good compromise choice allowing server performance
+ while also showing good interactive responsiveness even
+ on SMP and NUMA systems and exactly dividing by both PAL and
+ NTSC frame rates for video and multimedia work.

-endchoice
+ 1000 Hz is the preferred choice for desktop systems and other
+ systems requiring fast interactive responses to events.

config HZ
int
#<EOF>