1*ec8f24b7SThomas Gleixner# SPDX-License-Identifier: GPL-2.0-only 259121003SChristoph Lameter# 359121003SChristoph Lameter# Timer Interrupt Frequency Configuration 459121003SChristoph Lameter# 559121003SChristoph Lameter 659121003SChristoph Lameterchoice 759121003SChristoph Lameter prompt "Timer frequency" 859121003SChristoph Lameter default HZ_250 959121003SChristoph Lameter help 1059121003SChristoph Lameter Allows the configuration of the timer frequency. It is customary 1140fcfc87SAlan Cox to have the timer interrupt run at 1000 Hz but 100 Hz may be more 1259121003SChristoph Lameter beneficial for servers and NUMA systems that do not need to have 1359121003SChristoph Lameter a fast response for user interaction and that may experience bus 1459121003SChristoph Lameter contention and cacheline bounces as a result of timer interrupts. 1559121003SChristoph Lameter Note that the timer interrupt occurs on each processor in an SMP 1659121003SChristoph Lameter environment leading to NR_CPUS * HZ number of timer interrupts 1759121003SChristoph Lameter per second. 1859121003SChristoph Lameter 1959121003SChristoph Lameter 2059121003SChristoph Lameter config HZ_100 2159121003SChristoph Lameter bool "100 HZ" 2259121003SChristoph Lameter help 2340fcfc87SAlan Cox 100 Hz is a typical choice for servers, SMP and NUMA systems 2459121003SChristoph Lameter with lots of processors that may show reduced performance if 2559121003SChristoph Lameter too many timer interrupts are occurring. 2659121003SChristoph Lameter 2759121003SChristoph Lameter config HZ_250 2859121003SChristoph Lameter bool "250 HZ" 2959121003SChristoph Lameter help 3040fcfc87SAlan Cox 250 Hz is a good compromise choice allowing server performance 3159121003SChristoph Lameter while also showing good interactive responsiveness even 3240fcfc87SAlan Cox on SMP and NUMA systems. If you are going to be using NTSC video 3340fcfc87SAlan Cox or multimedia, selected 300Hz instead. 3440fcfc87SAlan Cox 3540fcfc87SAlan Cox config HZ_300 3640fcfc87SAlan Cox bool "300 HZ" 3740fcfc87SAlan Cox help 3840fcfc87SAlan Cox 300 Hz is a good compromise choice allowing server performance 3940fcfc87SAlan Cox while also showing good interactive responsiveness even 4040fcfc87SAlan Cox on SMP and NUMA systems and exactly dividing by both PAL and 4140fcfc87SAlan Cox NTSC frame rates for video and multimedia work. 4259121003SChristoph Lameter 4359121003SChristoph Lameter config HZ_1000 4459121003SChristoph Lameter bool "1000 HZ" 4559121003SChristoph Lameter help 4640fcfc87SAlan Cox 1000 Hz is the preferred choice for desktop systems and other 4759121003SChristoph Lameter systems requiring fast interactive responses to events. 4859121003SChristoph Lameter 4959121003SChristoph Lameterendchoice 5059121003SChristoph Lameter 5159121003SChristoph Lameterconfig HZ 5259121003SChristoph Lameter int 5359121003SChristoph Lameter default 100 if HZ_100 5459121003SChristoph Lameter default 250 if HZ_250 5540fcfc87SAlan Cox default 300 if HZ_300 5659121003SChristoph Lameter default 1000 if HZ_1000 5759121003SChristoph Lameter 588f4d37ecSPeter Zijlstraconfig SCHED_HRTICK 590a06ff06SChristoph Hellwig def_bool HIGH_RES_TIMERS 60