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Thomas Gleixnerec8f24b2019-05-19 13:07:45 +01001# SPDX-License-Identifier: GPL-2.0-only
Christoph Lameter59121002005-06-23 00:08:25 -07002#
3# Timer Interrupt Frequency Configuration
4#
5
6choice
7 prompt "Timer frequency"
8 default HZ_250
9 help
10 Allows the configuration of the timer frequency. It is customary
Alan Cox40fcfc82006-12-06 20:37:27 -080011 to have the timer interrupt run at 1000 Hz but 100 Hz may be more
Christoph Lameter59121002005-06-23 00:08:25 -070012 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
Alan Cox40fcfc82006-12-06 20:37:27 -080023 100 Hz is a typical choice for servers, SMP and NUMA systems
Christoph Lameter59121002005-06-23 00:08:25 -070024 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
Alan Cox40fcfc82006-12-06 20:37:27 -080030 250 Hz is a good compromise choice allowing server performance
Christoph Lameter59121002005-06-23 00:08:25 -070031 while also showing good interactive responsiveness even
Alan Cox40fcfc82006-12-06 20:37:27 -080032 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.
Christoph Lameter59121002005-06-23 00:08:25 -070042
43 config HZ_1000
44 bool "1000 HZ"
45 help
Alan Cox40fcfc82006-12-06 20:37:27 -080046 1000 Hz is the preferred choice for desktop systems and other
Christoph Lameter59121002005-06-23 00:08:25 -070047 systems requiring fast interactive responses to events.
48
49endchoice
50
51config HZ
52 int
53 default 100 if HZ_100
54 default 250 if HZ_250
Alan Cox40fcfc82006-12-06 20:37:27 -080055 default 300 if HZ_300
Christoph Lameter59121002005-06-23 00:08:25 -070056 default 1000 if HZ_1000
57
Peter Zijlstra8f4d37e2008-01-25 21:08:29 +010058config SCHED_HRTICK
Christoph Hellwig0a06ff02013-11-14 14:32:07 -080059 def_bool HIGH_RES_TIMERS