From 5b98e6197e75a4e708c3fbc654ca9c68788bfa45 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Wed, 15 Apr 2026 18:07:44 -0400
Subject: [PATCH] kernel: rollback to 6.12

Major ZFS issue causing deadlocks on my system:
https://github.com/openzfs/zfs/issues/18426
---
 configuration.nix | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/configuration.nix b/configuration.nix
index 6b12195..0be5282 100644
--- a/configuration.nix
+++ b/configuration.nix
@@ -133,8 +133,10 @@
   boot.kernel.sysctl."vm.nr_hugepages" = service_configs.hugepages_2m.total_pages;
 
   boot = {
-    # 6.18 LTS until 2027
-    kernelPackages = pkgs.linuxPackages_6_18;
+    # 6.12 LTS until 2027-03. Kernel 6.18 causes a reproducible ZFS deadlock
+    # in dbuf_evict due to page allocator changes (__free_frozen_pages).
+    # https://github.com/openzfs/zfs/issues/18426
+    kernelPackages = pkgs.linuxPackages_6_12;
 
     loader = {
       # Use the systemd-boot EFI boot loader.