29027fd1e1
Using pkgs.lib on the spine of module evaluation is problematic because the pkgs argument depends on the result of module evaluation. To prevent an infinite recursion, pkgs and some of the modules are evaluated twice, which is inefficient. Using ‘with lib’ prevents this problem.
54 lines
1.2 KiB
Nix
54 lines
1.2 KiB
Nix
{ config, lib, pkgs, ... }:
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with lib;
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{
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###### interface
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options = {
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powerManagement.cpuFreqGovernor = mkOption {
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type = types.nullOr types.str;
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default = null;
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example = "ondemand";
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description = ''
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Configure the governor used to regulate the frequence of the
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available CPUs. By default, the kernel configures the
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on-demand governor.
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'';
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};
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};
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###### implementation
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config = mkIf (config.powerManagement.cpuFreqGovernor != null) {
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environment.systemPackages = [ pkgs.cpufrequtils ];
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jobs.cpufreq =
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{ description = "CPU Frequency Governor Setup";
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after = [ "systemd-modules-load.service" ];
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wantedBy = [ "multi-user.target" ];
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unitConfig.ConditionPathIsReadWrite = "/sys/devices/";
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path = [ pkgs.cpufrequtils ];
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preStart = ''
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for i in $(seq 0 $(($(nproc) - 1))); do
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for gov in $(cpufreq-info -c $i -g); do
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if [ "$gov" = ${config.powerManagement.cpuFreqGovernor} ]; then
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echo "<6>setting governor on CPU $i to ‘$gov’"
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cpufreq-set -c $i -g $gov
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fi
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done
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done
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'';
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};
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};
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}
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