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-rw-r--r--arch/i386/Kconfig2
-rw-r--r--arch/x86_64/Kconfig2
-rw-r--r--include/asm-i386/param.h4
-rw-r--r--include/asm-x86_64/param.h6
-rw-r--r--kernel/Kconfig.hz46
5 files changed, 57 insertions, 3 deletions
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index bfdcede..d4ae5f9 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -961,6 +961,8 @@ config SECCOMP
If unsure, say Y. Only embedded should say N here.
+source kernel/Kconfig.hz
+
endmenu
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 61ed166..db25975 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -402,6 +402,8 @@ config SECCOMP
If unsure, say Y. Only embedded should say N here.
+source kernel/Kconfig.hz
+
endmenu
#
diff --git a/include/asm-i386/param.h b/include/asm-i386/param.h
index b644052..fa02e67 100644
--- a/include/asm-i386/param.h
+++ b/include/asm-i386/param.h
@@ -1,8 +1,10 @@
+#include <linux/config.h>
+
#ifndef _ASMi386_PARAM_H
#define _ASMi386_PARAM_H
#ifdef __KERNEL__
-# define HZ 1000 /* Internal kernel timer frequency */
+# define HZ CONFIG_HZ /* Internal kernel timer frequency */
# define USER_HZ 100 /* .. some user interfaces are in "ticks" */
# define CLOCKS_PER_SEC (USER_HZ) /* like times() */
#endif
diff --git a/include/asm-x86_64/param.h b/include/asm-x86_64/param.h
index b707f05..40b1193 100644
--- a/include/asm-x86_64/param.h
+++ b/include/asm-x86_64/param.h
@@ -1,9 +1,11 @@
+#include <linux/config.h>
+
#ifndef _ASMx86_64_PARAM_H
#define _ASMx86_64_PARAM_H
#ifdef __KERNEL__
-# define HZ 1000 /* Internal kernel timer frequency */
-# define USER_HZ 100 /* .. some user interfaces are in "ticks */
+# define HZ CONFIG_HZ /* Internal kernel timer frequency */
+# define USER_HZ 100 /* .. some user interfaces are in "ticks */
#define CLOCKS_PER_SEC (USER_HZ) /* like times() */
#endif
diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz
new file mode 100644
index 0000000..248e1c3
--- /dev/null
+++ b/kernel/Kconfig.hz
@@ -0,0 +1,46 @@
+#
+# 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.
+
+ 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.
+
+endchoice
+
+config HZ
+ int
+ default 100 if HZ_100
+ default 250 if HZ_250
+ default 1000 if HZ_1000
+
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