projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
| 59121003 CL |
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 | |
| 40fcfc87 | 11 | to have the timer interrupt run at 1000 Hz but 100 Hz may be more |
| 59121003 CL |
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 | |
| 40fcfc87 | 23 | 100 Hz is a typical choice for servers, SMP and NUMA systems |
| 59121003 CL |
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 | |
| 40fcfc87 | 30 | 250 Hz is a good compromise choice allowing server performance |
| 59121003 | 31 | while also showing good interactive responsiveness even |
| 40fcfc87 AC |
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. | |
| 59121003 CL |
42 | |
| 43 | config HZ_1000 | |
| 44 | bool "1000 HZ" | |
| 45 | help | |
| 40fcfc87 | 46 | 1000 Hz is the preferred choice for desktop systems and other |
| 59121003 CL |
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 | |
| 40fcfc87 | 55 | default 300 if HZ_300 |
| 59121003 CL |
56 | default 1000 if HZ_1000 |
| 57 | ||
| 8f4d37ec | 58 | config SCHED_HRTICK |
| 0a06ff06 | 59 | def_bool HIGH_RES_TIMERS |