kernel/Kconfig.hz

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