0001 # SPDX-License-Identifier: GPL-2.0-only
0002 #
0003 # Timer Interrupt Frequency Configuration
0004 #
0005
0006 choice
0007 prompt "Timer frequency"
0008 default HZ_250
0009 help
0010 Allows the configuration of the timer frequency. It is customary
0011 to have the timer interrupt run at 1000 Hz but 100 Hz may be more
0012 beneficial for servers and NUMA systems that do not need to have
0013 a fast response for user interaction and that may experience bus
0014 contention and cacheline bounces as a result of timer interrupts.
0015 Note that the timer interrupt occurs on each processor in an SMP
0016 environment leading to NR_CPUS * HZ number of timer interrupts
0017 per second.
0018
0019
0020 config HZ_100
0021 bool "100 HZ"
0022 help
0023 100 Hz is a typical choice for servers, SMP and NUMA systems
0024 with lots of processors that may show reduced performance if
0025 too many timer interrupts are occurring.
0026
0027 config HZ_250
0028 bool "250 HZ"
0029 help
0030 250 Hz is a good compromise choice allowing server performance
0031 while also showing good interactive responsiveness even
0032 on SMP and NUMA systems. If you are going to be using NTSC video
0033 or multimedia, selected 300Hz instead.
0034
0035 config HZ_300
0036 bool "300 HZ"
0037 help
0038 300 Hz is a good compromise choice allowing server performance
0039 while also showing good interactive responsiveness even
0040 on SMP and NUMA systems and exactly dividing by both PAL and
0041 NTSC frame rates for video and multimedia work.
0042
0043 config HZ_1000
0044 bool "1000 HZ"
0045 help
0046 1000 Hz is the preferred choice for desktop systems and other
0047 systems requiring fast interactive responses to events.
0048
0049 endchoice
0050
0051 config HZ
0052 int
0053 default 100 if HZ_100
0054 default 250 if HZ_250
0055 default 300 if HZ_300
0056 default 1000 if HZ_1000
0057
0058 config SCHED_HRTICK
0059 def_bool HIGH_RES_TIMERS
