projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 59121003 CL |
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. | |
| 32 | ||
| 33 | config HZ_1000 | |
| 34 | bool "1000 HZ" | |
| 35 | help | |
| 36 | 1000 HZ is the preferred choice for desktop systems and other | |
| 37 | systems requiring fast interactive responses to events. | |
| 38 | ||
| 39 | endchoice | |
| 40 | ||
| 41 | config HZ | |
| 42 | int | |
| 43 | default 100 if HZ_100 | |
| 44 | default 250 if HZ_250 | |
| 45 | default 1000 if HZ_1000 | |
| 46 |