2005-06-23 00:08:25 -07:00
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#
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# Timer Interrupt Frequency Configuration
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#
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choice
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prompt "Timer frequency"
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default HZ_250
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help
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Allows the configuration of the timer frequency. It is customary
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2006-12-06 20:37:27 -08:00
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to have the timer interrupt run at 1000 Hz but 100 Hz may be more
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2005-06-23 00:08:25 -07:00
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beneficial for servers and NUMA systems that do not need to have
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a fast response for user interaction and that may experience bus
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contention and cacheline bounces as a result of timer interrupts.
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Note that the timer interrupt occurs on each processor in an SMP
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environment leading to NR_CPUS * HZ number of timer interrupts
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per second.
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config HZ_100
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bool "100 HZ"
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help
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2006-12-06 20:37:27 -08:00
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100 Hz is a typical choice for servers, SMP and NUMA systems
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2005-06-23 00:08:25 -07:00
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with lots of processors that may show reduced performance if
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too many timer interrupts are occurring.
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config HZ_250
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bool "250 HZ"
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help
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2006-12-06 20:37:27 -08:00
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250 Hz is a good compromise choice allowing server performance
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2005-06-23 00:08:25 -07:00
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while also showing good interactive responsiveness even
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2006-12-06 20:37:27 -08:00
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on SMP and NUMA systems. If you are going to be using NTSC video
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or multimedia, selected 300Hz instead.
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config HZ_300
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bool "300 HZ"
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help
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300 Hz is a good compromise choice allowing server performance
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while also showing good interactive responsiveness even
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on SMP and NUMA systems and exactly dividing by both PAL and
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NTSC frame rates for video and multimedia work.
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2005-06-23 00:08:25 -07:00
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config HZ_1000
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bool "1000 HZ"
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help
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2006-12-06 20:37:27 -08:00
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1000 Hz is the preferred choice for desktop systems and other
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2005-06-23 00:08:25 -07:00
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systems requiring fast interactive responses to events.
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endchoice
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config HZ
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int
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default 100 if HZ_100
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default 250 if HZ_250
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2006-12-06 20:37:27 -08:00
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default 300 if HZ_300
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2005-06-23 00:08:25 -07:00
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default 1000 if HZ_1000
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2008-01-25 21:08:29 +01:00
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config SCHED_HRTICK
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2008-07-27 20:27:06 +09:00
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def_bool HIGH_RES_TIMERS && (!SMP || USE_GENERIC_SMP_HELPERS)
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