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