kernel/Kconfig.hz

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # Timer Interrupt Frequency Configuration
   4 #
   5
   6 choice
   7         prompt "Timer frequency"
   8         default HZ_250
   9         help
  10          Allows the configuration of the timer frequency. It is customary
  11          to have the timer interrupt run at 1000 Hz but 100 Hz may be more
  12          beneficial for servers and NUMA systems that do not need to have
  13          a fast response for user interaction and that may experience bus
  14          contention and cacheline bounces as a result of timer interrupts.
  15          Note that the timer interrupt occurs on each processor in an SMP
  16          environment leading to NR_CPUS * HZ number of timer interrupts
  17          per second.
  18
  19
  20         config HZ_100
  21                 bool "100 HZ"
  22         help
  23           100 Hz is a typical choice for servers, SMP and NUMA systems
  24           with lots of processors that may show reduced performance if
  25           too many timer interrupts are occurring.
  26
  27         config HZ_250
  28                 bool "250 HZ"
  29         help
  30          250 Hz is a good compromise choice allowing server performance
  31          while also showing good interactive responsiveness even
  32          on SMP and NUMA systems. If you are going to be using NTSC video
  33          or multimedia, selected 300Hz instead.
  34
  35         config HZ_300
  36                 bool "300 HZ"
  37         help
  38          300 Hz is a good compromise choice allowing server performance
  39          while also showing good interactive responsiveness even
  40          on SMP and NUMA systems and exactly dividing by both PAL and
  41          NTSC frame rates for video and multimedia work.
  42
  43         config HZ_1000
  44                 bool "1000 HZ"
  45         help
  46          1000 Hz is the preferred choice for desktop systems and other
  47          systems requiring fast interactive responses to events.
  48
  49 endchoice
  50
  51 config HZ
  52         int
  53         default 100 if HZ_100
  54         default 250 if HZ_250
  55         default 300 if HZ_300
  56         default 1000 if HZ_1000
  57
  58 config SCHED_HRTICK
  59         def_bool HIGH_RES_TIMERS