From 8b3fd3ed49d2ce36ccef076e5b2b9f820cda70ea Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 2 Sep 2011 13:19:45 +0000
Subject: [PATCH] =?UTF-8?q?*=20Use=20the=20CFQ=20I/O=20scheduler,=20rather?=
 =?UTF-8?q?=20than=20the=20=E2=80=98none=E2=80=99=20scheduler.=20=20This?=
 =?UTF-8?q?=20=20=20was=20already=20the=20case=20on=20Linux=202.6.32,=20bu?=
 =?UTF-8?q?t=20in=20newer=20kernels=20the=20CFQ=20=20=20scheduler=20is=20b?=
 =?UTF-8?q?uilt=20as=20a=20module,=20so=20all=20block=20devices=20got=20th?=
 =?UTF-8?q?e=20=E2=80=98none=E2=80=99=20=20=20scheduler=20instead.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

svn path=/nixos/trunk/; revision=28972
---
 modules/system/boot/kernel.nix | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/modules/system/boot/kernel.nix b/modules/system/boot/kernel.nix
index 1f7ea8674fa..1f2d688c13f 100644
--- a/modules/system/boot/kernel.nix
+++ b/modules/system/boot/kernel.nix
@@ -49,7 +49,7 @@ let kernel = config.boot.kernelPackages.kernel; in
       default = true;
       example = false;
       description = ''
-        Whether to activate VESA video mode on boot
+        Whether to activate VESA video mode on boot.
       '';
     };
 
@@ -91,8 +91,7 @@ let kernel = config.boot.kernelPackages.kernel; in
     };
     
     boot.initrd.kernelModules = mkOption {
-      default = [
-      ];
+      default = [];
       description = "List of modules that are always loaded by the initrd.";
     };
 
@@ -121,7 +120,10 @@ let kernel = config.boot.kernelPackages.kernel; in
     system.modulesTree = [ kernel ] ++ config.boot.extraModulePackages;
 
     boot.kernelParams =
-      [ "splash=verbose" ] ++ 
+      [ "splash=verbose"
+        # Force the Completely Fair Scheduler to be used by default.
+        "elevator=cfq"
+      ] ++ 
       optional config.boot.vesa "vga=0x317";
       
     boot.kernelModules = [ "loop" ];
@@ -162,6 +164,9 @@ let kernel = config.boot.kernelPackages.kernel; in
 
         # Unix domain sockets (needed by udev).
         "unix"
+
+        # Provide the CFQ scheduler in the initrd.
+        "cfq_iosched"
         
         # Misc. stuff.
         "pcips2" "serio" "atkbd" "xtkbd"
@@ -170,8 +175,9 @@ let kernel = config.boot.kernelPackages.kernel; in
     boot.initrd.kernelModules =
       [ # For LVM.
         "dm_mod"
-        # For usual AT keyboards
-        "i8042" 
+        
+        # For usual AT keyboards.
+        "i8042"        
       ];
 
     # The Linux kernel >= 2.6.27 provides firmware.