| # |
| # Timer Interrupt Frequency Configuration |
| # |
| |
| choice |
| prompt "Timer frequency" |
| default HZ_250 |
| help |
| Allows the configuration of the timer frequency. It is customary |
| to have the timer interrupt run at 1000 Hz but 100 Hz may be more |
| beneficial for servers and NUMA systems that do not need to have |
| a fast response for user interaction and that may experience bus |
| contention and cacheline bounces as a result of timer interrupts. |
| Note that the timer interrupt occurs on each processor in an SMP |
| environment leading to NR_CPUS * HZ number of timer interrupts |
| per second. |
| |
| |
| config HZ_100 |
| bool "100 HZ" |
| help |
| 100 Hz is a typical choice for servers, SMP and NUMA systems |
| with lots of processors that may show reduced performance if |
| too many timer interrupts are occurring. |
| |
| config HZ_250 |
| bool "250 HZ" |
| help |
| 250 Hz is a good compromise choice allowing server performance |
| while also showing good interactive responsiveness even |
| on SMP and NUMA systems. If you are going to be using NTSC video |
| or multimedia, selected 300Hz instead. |
| |
| config HZ_300 |
| bool "300 HZ" |
| help |
| 300 Hz is a good compromise choice allowing server performance |
| while also showing good interactive responsiveness even |
| on SMP and NUMA systems and exactly dividing by both PAL and |
| NTSC frame rates for video and multimedia work. |
| |
| config HZ_1000 |
| bool "1000 HZ" |
| help |
| 1000 Hz is the preferred choice for desktop systems and other |
| systems requiring fast interactive responses to events. |
| |
| endchoice |
| |
| config HZ |
| int |
| default 100 if HZ_100 |
| default 250 if HZ_250 |
| default 300 if HZ_300 |
| default 1000 if HZ_1000 |
| |
| config SCHED_HRTICK |
| def_bool HIGH_RES_TIMERS && (!SMP || USE_GENERIC_SMP_HELPERS) |