Messages in this thread Patch in this message | | | Date | Mon, 16 May 2005 12:45:29 -0700 (PDT) | From | christoph <> | Subject | [PATCH] i386: Selectable Frequency of the Timer Interrupt. |
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Make the timer frequency selectable. The timer interrupt may cause bus and memory contention in large NUMA systems since the interrupt occurs on each processor HZ times per second.
Signed-off-by: Christoph Lameter <christoph@scale86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org>
Index: linux-2.6.11/arch/i386/Kconfig =================================================================== --- linux-2.6.11.orig/arch/i386/Kconfig 2005-05-16 12:07:31.000000000 -0700 +++ linux-2.6.11/arch/i386/Kconfig 2005-05-16 12:39:48.000000000 -0700 @@ -939,6 +939,20 @@ config SECCOMP If unsure, say Y. Only embedded should say N here. +config HZ + int "Frequency of the Timer Interrupt (1000 or 100)" + range 100 1000 + default 1000 + 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. + endmenu Index: linux-2.6.11/include/asm-i386/param.h =================================================================== --- linux-2.6.11.orig/include/asm-i386/param.h 2005-05-16 12:07:25.000000000 -0700 +++ linux-2.6.11/include/asm-i386/param.h 2005-05-16 12:09:04.000000000 -0700 @@ -2,7 +2,7 @@ #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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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