Introduce config.me.optimizations.enable to toggle optimizations.

This is more granular than the buildingIso setting.

nix/configuration/flake.nix

@@ -137,6 +137,7 @@
                   isoImage.makeEfiBootable = true;
                   isoImage.makeUsbBootable = true;
                   me.buildingIso = true;
+                  me.optimizations.enable = false;
                 }
               ];
             }
@@ -163,6 +164,7 @@
                   isoImage.makeEfiBootable = true;
                   isoImage.makeUsbBootable = true;
                   me.buildingIso = true;
+                  me.optimizations.enable = false;
                 }
               ];
             }
@@ -187,6 +189,7 @@
                   isoImage.makeEfiBootable = true;
                   isoImage.makeUsbBootable = true;
                   me.buildingIso = true;
+                  me.optimizations.enable = false;
                 }
               ];
             }

nix/configuration/hosts/hydra/default.nix

@@ -36,6 +36,7 @@
   time.timeZone = "America/New_York";
   i18n.defaultLocale = "en_US.UTF-8";
 
+  me.optimizations.enable = true;
   me.secureBoot.enable = false;
 
   # Mount tmpfs at /tmp

nix/configuration/hosts/neelix/default.nix

@@ -15,6 +15,7 @@
   time.timeZone = "America/New_York";
   i18n.defaultLocale = "en_US.UTF-8";
 
+  me.optimizations.enable = false;
   me.secureBoot.enable = false;
 
   # Early KMS

nix/configuration/hosts/neelix/optimized_build.nix

@@ -9,22 +9,15 @@
 
   config = lib.mkMerge [
     { }
-    (lib.mkIf (!config.me.buildingIso) {
+    (lib.mkIf (!config.me.optimizations.enable) {
-      nix.settings.system-features = lib.mkForce [
+      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_6_13;
-        "gccarch-alderlake"
+    })
-        "gccarch-x86-64-v3"
+    (lib.mkIf (config.me.optimizations.enable) {
-        "benchmark"
+      nixpkgs.hostPlatform = {
-        "big-parallel"
+        gcc.arch = "alderlake";
-        "kvm"
+        gcc.tune = "alderlake";
-        "nixos-test"
+        system = "x86_64-linux";
-      ];
+      };
-
-      # nixpkgs.hostPlatform = {
-      #   gcc.arch = "alderlake";
-      #   gcc.tune = "alderlake";
-      #   system = "x86_64-linux";
-
-      # };
 
       nixpkgs.overlays = [
         (
@@ -42,7 +35,7 @@
               });
           in
           {
-            linux_alderlake =
+            linux_me =
               addConfig
                 {
                   # Full preemption
@@ -68,10 +61,19 @@
         )
       ];
 
-      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_alderlake;
+      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_me;
+    })
+    (lib.mkIf (!config.me.buildingIso) {
+      nix.settings.system-features = lib.mkForce [
+        "gccarch-alderlake"
+        "gccarch-x86-64-v3"
+        "benchmark"
+        "big-parallel"
+        "kvm"
+        "nixos-test"
+      ];
     })
     (lib.mkIf (config.me.buildingIso) {
-      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_6_12;
       boot.supportedFilesystems = [ "zfs" ];
     })
   ];

nix/configuration/hosts/odo/default.nix

@@ -24,6 +24,7 @@
   time.timeZone = "America/New_York";
   i18n.defaultLocale = "en_US.UTF-8";
 
+  me.optimizations.enable = true;
   me.secureBoot.enable = true;
 
   # Early KMS

nix/configuration/hosts/odo/optimized_build.nix

@@ -10,27 +10,10 @@
 
   config = lib.mkMerge [
     { }
-    (lib.mkIf (!config.me.buildingIso) {
+    (lib.mkIf (!config.me.optimizations.enable) {
-      nix.settings.system-features = lib.mkForce [
+      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_6_14;
-        "gccarch-znver4"
+    })
-        "gccarch-skylake"
+    (lib.mkIf (config.me.optimizations.enable) {
-        # "gccarch-alderlake" missing WAITPKG
-        "gccarch-x86-64-v3"
-        "gccarch-x86-64-v4"
-        "benchmark"
-        "big-parallel"
-        "kvm"
-        "nixos-test"
-      ];
-
-      # Keep ALL dependencies so we can rebuild offline. This DRASTICALLY increase disk usage, but disk space is cheap.
-      # system.includeBuildDependencies = true;
-
-      nix.extraOptions = ''
-        keep-outputs = true
-        keep-derivations = true
-      '';
-
       nixpkgs.hostPlatform = {
         gcc.arch = "znver4";
         gcc.tune = "znver4";
@@ -103,8 +86,41 @@
 
       boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_me;
     })
+    (lib.mkIf (!config.me.buildingIso) {
+      nix.settings.system-features = lib.mkForce [
+        "gccarch-znver4"
+        "gccarch-skylake"
+        # "gccarch-alderlake" missing WAITPKG
+        "gccarch-x86-64-v3"
+        "gccarch-x86-64-v4"
+        "benchmark"
+        "big-parallel"
+        "kvm"
+        "nixos-test"
+      ];
+
+      # Keep ALL dependencies so we can rebuild offline. This DRASTICALLY increase disk usage, but disk space is cheap.
+      # system.includeBuildDependencies = true;
+
+      # This also should enable building offline? TODO: test.
+      nix.extraOptions = ''
+        keep-outputs = true
+        keep-derivations = true
+      '';
+
+      # # building ON
+      # nixpkgs.localSystem = { system = "aarch64-linux"; };
+      # # building FOR
+      # nixpkgs.crossSystem = { system = "aarch64-linux"; };
+
+      # nixpkgs.config = {
+      #   replaceStdenv = ({ pkgs }: pkgs.clangStdenv);
+      # };
+      # or maybe an overlay
+      # stdenv = prev.clangStdenv;
+
+    })
     (lib.mkIf (config.me.buildingIso) {
-      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_6_14;
       boot.supportedFilesystems.zfs = true;
     })
   ];

nix/configuration/hosts/quark/default.nix

@@ -22,6 +22,7 @@
   time.timeZone = "America/New_York";
   i18n.defaultLocale = "en_US.UTF-8";
 
+  me.optimizations.enable = true;
   me.secureBoot.enable = true;
 
   # Early KMS

nix/configuration/hosts/quark/optimized_build.nix

@@ -10,46 +10,16 @@
 
   config = lib.mkMerge [
     { }
-    (lib.mkIf (!config.me.buildingIso) {
+    (lib.mkIf (!config.me.optimizations.enable) {
-      nix.settings.system-features = lib.mkForce [
+      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_6_14;
-        "gccarch-znver4"
+    })
-        "gccarch-znver5"
+    (lib.mkIf (config.me.optimizations.enable) {
-        "gccarch-skylake"
-        # "gccarch-alderlake" missing WAITPKG
-        "gccarch-x86-64-v3"
-        "gccarch-x86-64-v4"
-        "benchmark"
-        "big-parallel"
-        "kvm"
-        "nixos-test"
-      ];
-
-      # Keep ALL dependencies so we can rebuild offline. This DRASTICALLY increase disk usage, but disk space is cheap.
-      # system.includeBuildDependencies = true;
-
-      # This also should enable building offline? TODO: test.
-      nix.extraOptions = ''
-        keep-outputs = true
-        keep-derivations = true
-      '';
-
       nixpkgs.hostPlatform = {
         gcc.arch = "znver5";
         gcc.tune = "znver5";
         system = "x86_64-linux";
       };
 
-      # # building ON
-      # nixpkgs.localSystem = { system = "aarch64-linux"; };
-      # # building FOR
-      # nixpkgs.crossSystem = { system = "aarch64-linux"; };
-
-      # nixpkgs.config = {
-      #   replaceStdenv = ({ pkgs }: pkgs.clangStdenv);
-      # };
-      # or maybe an overlay
-      # stdenv = prev.clangStdenv;
-
       nixpkgs.overlays = [
         (
           final: prev:
@@ -110,8 +80,42 @@
 
       boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_me;
     })
+    (lib.mkIf (!config.me.buildingIso) {
+      nix.settings.system-features = lib.mkForce [
+        "gccarch-znver4"
+        "gccarch-znver5"
+        "gccarch-skylake"
+        # "gccarch-alderlake" missing WAITPKG
+        "gccarch-x86-64-v3"
+        "gccarch-x86-64-v4"
+        "benchmark"
+        "big-parallel"
+        "kvm"
+        "nixos-test"
+      ];
+
+      # Keep ALL dependencies so we can rebuild offline. This DRASTICALLY increase disk usage, but disk space is cheap.
+      # system.includeBuildDependencies = true;
+
+      # This also should enable building offline? TODO: test.
+      nix.extraOptions = ''
+        keep-outputs = true
+        keep-derivations = true
+      '';
+
+      # # building ON
+      # nixpkgs.localSystem = { system = "aarch64-linux"; };
+      # # building FOR
+      # nixpkgs.crossSystem = { system = "aarch64-linux"; };
+
+      # nixpkgs.config = {
+      #   replaceStdenv = ({ pkgs }: pkgs.clangStdenv);
+      # };
+      # or maybe an overlay
+      # stdenv = prev.clangStdenv;
+
+    })
     (lib.mkIf (config.me.buildingIso) {
-      boot.kernelPackages = pkgs.linuxPackagesFor pkgs.linux_6_14;
       boot.supportedFilesystems.zfs = true;
     })
   ];

nix/configuration/roles/global_options/default.nix

@@ -9,7 +9,12 @@
   imports = [ ];
 
   options.me = {
-
+    optimizations.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to enable CPU optimizations (will trigger a rebuild from source).";
+    };
   };
 
   # options.me.graphics_card_type = lib.mkOption {