hugepages changes

configuration.nix

@@ -118,6 +118,9 @@
 
   hardware.intelgpu.driver = "xe";
 
+  # Per-service 2MB hugepage budget calculated in service-configs.nix.
+  boot.kernel.sysctl."vm.nr_hugepages" = service_configs.hugepages_2m.total_pages;
+
   boot = {
     # 6.12 LTS until 2026
     kernelPackages = pkgs.linuxPackages_6_12_hardened;

flake.lock

@@ -47,11 +47,11 @@
     },
     "crane": {
       "locked": {
-        "lastModified": 1771796463,
+        "lastModified": 1772080396,
-        "narHash": "sha256-9bCDuUzpwJXcHMQYMS1yNuzYMmKO/CCwCexpjWOl62I=",
+        "narHash": "sha256-84W9UNtSk9DNMh43WBkOjpkbfODlmg+RDi854PnNgLE=",
         "owner": "ipetkov",
         "repo": "crane",
-        "rev": "3d3de3313e263e04894f284ac18177bd26169bad",
+        "rev": "8525580bc0316c39dbfa18bd09a1331e98c9e463",
         "type": "github"
       },
       "original": {
@@ -89,11 +89,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1773025010,
+        "lastModified": 1773506317,
-        "narHash": "sha256-khlHllTsovXgT2GZ0WxT4+RvuMjNeR5OW0UYeEHPYQo=",
+        "narHash": "sha256-qWKbLUJpavIpvOdX1fhHYm0WGerytFHRoh9lVck6Bh0=",
         "owner": "nix-community",
         "repo": "disko",
-        "rev": "7b9f7f88ab3b339f8142dc246445abb3c370d3d3",
+        "rev": "878ec37d6a8f52c6c801d0e2a2ad554c75b9353c",
         "type": "github"
       },
       "original": {
@@ -197,11 +197,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1772985280,
+        "lastModified": 1773264488,
-        "narHash": "sha256-FdrNykOoY9VStevU4zjSUdvsL9SzJTcXt4omdEDZDLk=",
+        "narHash": "sha256-rK0507bDuWBrZo+0zts9bCs/+RRUEHuvFE5DHWPxX/Q=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "8f736f007139d7f70752657dff6a401a585d6cbc",
+        "rev": "5c0f63f8d55040a7eed69df7e3fcdd15dfb5a04c",
         "type": "github"
       },
       "original": {
@@ -263,11 +263,11 @@
         "rust-overlay": "rust-overlay"
       },
       "locked": {
-        "lastModified": 1772216104,
+        "lastModified": 1773344150,
-        "narHash": "sha256-1TnGN26vnCEQk5m4AavJZxGZTb/6aZyphemRPRwFUfs=",
+        "narHash": "sha256-JSsXufJy2zdg5XS5pRGlkwF1dqN+sWPmCgrvJsnhEzg=",
         "owner": "nix-community",
         "repo": "lanzaboote",
-        "rev": "dbe5112de965bbbbff9f0729a9789c20a65ab047",
+        "rev": "d21013305ef39e1d9d2d06b161c3785ffad82281",
         "type": "github"
       },
       "original": {
@@ -285,11 +285,11 @@
         "systems": "systems_3"
       },
       "locked": {
-        "lastModified": 1772592046,
+        "lastModified": 1773456096,
-        "narHash": "sha256-+Lyl+mGVd0t2nlR6ODK/gvUHzMtF5qLlbTK+x5tCenU=",
+        "narHash": "sha256-vlV3HnHBxnfW4a2ifabH3L/3iGGjA5ejEP7XD7EOC+E=",
         "owner": "Infinidoge",
         "repo": "nix-minecraft",
-        "rev": "483abf9ad6aeac1d61f2a5419ded2879f0c4795e",
+        "rev": "ce7440a5fced512773e8e695d8a7bd57f33c7e6d",
         "type": "github"
       },
       "original": {
@@ -316,11 +316,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1773068389,
+        "lastModified": 1773375660,
-        "narHash": "sha256-vMrm7Pk2hjBRPnCSjhq1pH0bg350Z+pXhqZ9ICiqqCs=",
+        "narHash": "sha256-SEzUWw2Rf5Ki3bcM26nSKgbeoqi2uYy8IHVBqOKjX3w=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "44bae273f9f82d480273bab26f5c50de3724f52f",
+        "rev": "3e20095fe3c6cbb1ddcef89b26969a69a1570776",
         "type": "github"
       },
       "original": {
@@ -333,11 +333,11 @@
     "nixpkgs-p2pool-module": {
       "flake": false,
       "locked": {
-        "lastModified": 1764744779,
+        "lastModified": 1773298780,
-        "narHash": "sha256-15mhGU8HZq4e6U2WnIhQvJNuUmU5aIO0RHMjzv9gVZs=",
+        "narHash": "sha256-7awJKfaH2uTuuW6gyA/lmPPfSruObm7bIkiYADxZBro=",
         "owner": "JacoMalan1",
         "repo": "nixpkgs",
-        "rev": "3784f8a0dc56806ffbc550701d3aa27436ebb3e5",
+        "rev": "501e6bb1697590473c87c2ff9d2a92043a8d0e06",
         "type": "github"
       },
       "original": {
@@ -373,11 +373,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1771858127,
+        "lastModified": 1772024342,
-        "narHash": "sha256-Gtre9YoYl3n25tJH2AoSdjuwcqij5CPxL3U3xysYD08=",
+        "narHash": "sha256-+eXlIc4/7dE6EcPs9a2DaSY3fTA9AE526hGqkNID3Wg=",
         "owner": "cachix",
         "repo": "pre-commit-hooks.nix",
-        "rev": "49bbbfc218bf3856dfa631cead3b052d78248b83",
+        "rev": "6e34e97ed9788b17796ee43ccdbaf871a5c2b476",
         "type": "github"
       },
       "original": {
@@ -415,11 +415,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1771988922,
+        "lastModified": 1772334676,
-        "narHash": "sha256-Fc6FHXtfEkLtuVJzd0B6tFYMhmcPLuxr90rWfb/2jtQ=",
+        "narHash": "sha256-Jrc0J3AH+iNJDlUze3+FJZv2R0BZnhANFnD52V4kyvI=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "f4443dc3f0b6c5e6b77d923156943ce816d1fcb9",
+        "rev": "9879be11f30fd3bbf848e653a7f991549e8973b5",
         "type": "github"
       },
       "original": {
@@ -472,11 +472,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1773021923,
+        "lastModified": 1773369348,
-        "narHash": "sha256-ro+i3wNoD2p5FloGGlkCzdmzgBDeq2LJwaIpaI9Dk7Q=",
+        "narHash": "sha256-6UwMEAi6X3oMjKQm51i0+3i10DrsrSdXi/4YgmJxfhE=",
         "owner": "nix-community",
         "repo": "srvos",
-        "rev": "7f92c2bcbeb42ce87770a7565f0e6f92c8134354",
+        "rev": "f3f0277b1dee1bfd058c5b8b98cb25558d95f03f",
         "type": "github"
       },
       "original": {
@@ -548,11 +548,11 @@
     "trackerlist": {
       "flake": false,
       "locked": {
-        "lastModified": 1773184165,
+        "lastModified": 1773529772,
-        "narHash": "sha256-uGD+QgYZD1ntXl43523bKziyBUs1c3ONi+n5FeFZre0=",
+        "narHash": "sha256-I+K0BCc7fNQp6N7mTE/3SIHfencR4l0+sRsom4xaZ8Y=",
         "owner": "ngosang",
         "repo": "trackerslist",
-        "rev": "448eba328ad00172a4ba049ec9f9f073b9cd278b",
+        "rev": "7e16f4f09851ef5e196806bddc0526281f913d3e",
         "type": "github"
       },
       "original": {

service-configs.nix

@@ -60,6 +60,7 @@ rec {
   postgres = {
     socket = "/run/postgresql";
     dataDir = services_dir + "/sql";
+    shared_buffers_m = 128; # PostgreSQL default; update if you change shared_buffers
   };
 
   immich = {
@@ -150,4 +151,25 @@ rec {
     moviesDir = torrents_path + "/media/movies";
     tvDir = torrents_path + "/media/tv";
   };
+
+  # Per-service 2MB hugepage budget.
+  # Each value is the service's hugepage consumption in MB, derived from
+  # its actual memory configuration. The kernel sysctl vm.nr_hugepages
+  # is set to total_pages so every service gets what it needs.
+  hugepages_2m = rec {
+    page_size_m = 2;
+
+    # RandomX dataset (2048MB) + cache (256MB) = 2304MB per instance.
+    # Both monerod and p2pool allocate their own full copy via MAP_HUGETLB.
+    randomx_instance_m = 2048 + 256;
+
+    services = {
+      minecraft_m = minecraft.memory.heap_size_m; # JVM heap via -XX:+UseLargePages
+      monerod_m = randomx_instance_m; # block verification dataset
+      p2pool_m = randomx_instance_m; # mining dataset
+      postgres_m = postgres.shared_buffers_m; # huge_pages = try (default)
+    };
+
+    total_pages = builtins.foldl' (a: b: a + b) 0 (builtins.attrValues services) / page_size_m;
+  };
 }

services/minecraft.nix

@@ -27,14 +27,6 @@
   boot.kernel.sysctl = {
     # Disable autogroup for better scheduling of game server threads
     "kernel.sched_autogroup_enabled" = 0;
-
-    # We want to determine the number of hugepages based on how many minecraft needs.
-    # This can be determined by dividing the heap size by the size of a large page.
-    # Doing this gives us how many large pages are needed.
-    # Then we add 300 to give some headroom.
-    "vm.nr_hugepages" =
-      (service_configs.minecraft.memory.heap_size_m / service_configs.minecraft.memory.large_page_size_m)
-      + 300;
   };
 
   services.minecraft-servers = {
@@ -110,8 +102,8 @@
             };
 
             Lithium = fetchurl {
-              url = "https://cdn.modrinth.com/data/gvQqBUqZ/versions/qvNsoO3l/lithium-fabric-0.21.3%2Bmc1.21.11.jar";
+              url = "https://cdn.modrinth.com/data/gvQqBUqZ/versions/Ow7wA0kG/lithium-fabric-0.21.4%2Bmc1.21.11.jar";
-              sha512 = "2883739303f0bb602d3797cc601ed86ce6833e5ec313ddce675f3d6af3ee6a40b9b0a06dafe39d308d919669325e95c0aafd08d78c97acd976efde899c7810fd";
+              sha512 = "f14a5c3d2fad786347ca25083f902139694f618b7c103947f2fd067a7c5ee88a63e1ef8926f7d693ea79ed7d00f57317bae77ef9c2d630bf5ed01ac97a752b94";
             };
 
             NoChatReports = fetchurl {