78 lines
2.3 KiB
Plaintext
78 lines
2.3 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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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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to have the timer interrupt run at 1000 Hz but 100 Hz may be more
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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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100 Hz is a typical choice for servers, SMP and NUMA systems
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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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250 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. 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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config HZ_1000
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bool "1000 HZ"
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help
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1000 Hz is the preferred choice for desktop systems and other
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systems requiring fast interactive responses to events.
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config HZ_10
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bool "10 HZ"
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depends on MCST && E2K # only under CONFIG_MCST && CONFIG_E2K
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help
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10 Hz is a typical choice for simulator e2k arch.
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Such a low HZ due to the low frequency of simulated hardware.
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config HZ_20
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bool "20 HZ"
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depends on MCST # only under CONFIG_MCST
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help
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20 Hz is a typical choice for simulator e2k/x86 arch.
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It is the minimum HZ value for x86 to do not cause an overflow
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of 16 bits 'PIT_LATCH' (PIT timer counter).
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Such a low HZ due to the low frequency of simulated hardware.
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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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default 300 if HZ_300
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default 1000 if HZ_1000
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default 10 if HZ_10 # only under CONFIG_MCST && CONFIG_E2K
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default 20 if HZ_20 # only under CONFIG_MCST
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config SCHED_HRTICK
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def_bool HIGH_RES_TIMERS
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