linux: Enable some kernel features

This enables a few features that should be useful and safe (they're
all used by the default Ubuntu kernel config), in particular zswap,
wakelocks, kernel load address randomization, userfaultfd (useful for
QEMU), paravirtualized spinlocks and automatic process group
scheduling.

Also removes some configuration conditional on kernel versions that we
no longer support.

1 files changed, 41 insertions, 71 deletions

diff --git a/pkgs/os-specific/linux/kernel/common-config.nix b/pkgs/os-specific/linux/kernel/common-config.nix
index 62dd7caadbf..37da42f8c0d 100644
--- a/pkgs/os-specific/linux/kernel/common-config.nix
+++ b/pkgs/os-specific/linux/kernel/common-config.nix
@@ -67,6 +67,7 @@ with stdenv.lib;
   ${optionalString (versionOlder version "3.10") ''
     USB_SUSPEND y
   ''}
+  PM_WAKELOCKS y
 
   # Support drivers that need external firmware.
   STANDALONE n
@@ -98,9 +99,6 @@ with stdenv.lib;
   DONGLE y # Serial dongle support
   HIPPI y
   MTD_COMPLEX_MAPPINGS y # needed for many devices
-  ${optionalString (versionOlder version "3.2") ''
-    NET_POCKET y # enable pocket and portable adapters
-  ''}
   SCSI_LOWLEVEL y # enable lots of SCSI devices
   SCSI_LOWLEVEL_PCMCIA y
   SCSI_SAS_ATA y  # added to enable detection of hard drive
@@ -137,9 +135,7 @@ with stdenv.lib;
   HOSTAP_FIRMWARE_NVRAM? y
   ATH9K_PCI? y # Detect Atheros AR9xxx cards on PCI(e) bus
   ATH9K_AHB? y # Ditto, AHB bus
-  ${optionalString (versionAtLeast version "3.2") ''
-    B43_PHY_HT? y
-  ''}
+  B43_PHY_HT? y
   BCMA_HOST_PCI? y
 
   # Enable various FB devices.
@@ -157,7 +153,7 @@ with stdenv.lib;
   FB_VESA y
   FRAMEBUFFER_CONSOLE y
   FRAMEBUFFER_CONSOLE_ROTATION y
-  ${optionalString (versionOlder version "3.9" || stdenv.system == "i686-linux") ''
+  ${optionalString (stdenv.system == "i686-linux") ''
     FB_GEODE y
   ''}
 
@@ -168,11 +164,7 @@ with stdenv.lib;
   ''}
   # Allow specifying custom EDID on the kernel command line
   DRM_LOAD_EDID_FIRMWARE y
-  ${optionalString (versionOlder version "3.9") ''
-    DRM_RADEON_KMS? y
-  ''}
-  # Hybrid graphics support
-  VGA_SWITCHEROO y
+  VGA_SWITCHEROO y # Hybrid graphics support
 
   # Sound.
   SND_DYNAMIC_MINORS y
@@ -231,9 +223,7 @@ with stdenv.lib;
     NFSD_V4_SECURITY_LABEL y
   ''}
   NFS_FSCACHE y
-  ${optionalString (versionAtLeast version "3.6") ''
-    NFS_SWAP y
-  ''}
+  NFS_SWAP y
   NFS_V3_ACL y
   ${optionalString (versionAtLeast version "3.11") ''
     NFS_V4_1 y  # NFSv4.1 client support
@@ -265,6 +255,7 @@ with stdenv.lib;
   DEBUG_SET_MODULE_RONX? y # Detect writes to read-only module pages
 
   # Security related features.
+  RANDOMIZE_BASE y
   STRICT_DEVMEM y # Filter access to /dev/mem
   SECURITY_SELINUX_BOOTPARAM_VALUE 0 # Disable SELinux by default
   DEVKMEM n # Disable /dev/kmem
@@ -310,25 +301,25 @@ with stdenv.lib;
   BT_HCIUART_BCSP? y
   BT_HCIUART_H4? y # UART (H4) protocol support
   BT_HCIUART_LL? y
-  ${optionalString (versionAtLeast version "3.4") ''
-    BT_RFCOMM_TTY? y # RFCOMM TTY support
-  ''}
+  BT_RFCOMM_TTY? y # RFCOMM TTY support
+  CLEANCACHE? y
   CRASH_DUMP? n
-  ${optionalString (versionOlder version "3.1") ''
-    DMAR? n # experimental
-  ''}
   DVB_DYNAMIC_MINORS? y # we use udev
-  ${optionalString (versionAtLeast version "3.3") ''
-    EFI_STUB y # EFI bootloader in the bzImage itself
-  ''}
+  EFI_STUB y # EFI bootloader in the bzImage itself
   FHANDLE y # used by systemd
+  FRONTSWAP y
   FUSION y # Fusion MPT device support
   IDE_GD_ATAPI y # ATAPI floppy support
+  ${optionalString (versionAtLeast version "4.3") ''
+    IDLE_PAGE_TRACKING y
+  ''}
   IRDA_ULTRA y # Ultra (connectionless) protocol
   JOYSTICK_IFORCE_232? y # I-Force Serial joysticks and wheels
   JOYSTICK_IFORCE_USB? y # I-Force USB joysticks and wheels
   JOYSTICK_XPAD_FF? y # X-Box gamepad rumble support
   JOYSTICK_XPAD_LEDS? y # LED Support for Xbox360 controller 'BigX' LED
+  KEXEC_FILE y
+  KEXEC_JUMP y
   LDM_PARTITION y # Windows Logical Disk Manager (Dynamic Disk) support
   LEDS_TRIGGER_IDE_DISK y # LED IDE Disk Trigger
   LOGIRUMBLEPAD2_FF y # Logitech Rumblepad 2 force feedback
@@ -349,12 +340,9 @@ with stdenv.lib;
   PPP_MULTILINK y # PPP multilink support
   PPP_FILTER y
   REGULATOR y # Voltage and Current Regulator Support
-  ${optionalString (versionAtLeast version "3.6") ''
-    RC_DEVICES? y # Enable IR devices
-  ''}
-  ${optionalString (versionAtLeast version "3.10") ''
-    RT2800USB_RT55XX y
-  ''}
+  RC_DEVICES? y # Enable IR devices
+  RT2800USB_RT55XX y
+  SCHED_AUTOGROUP y
   SCSI_LOGGING y # SCSI logging facility
   SERIAL_8250 y # 8250/16550 and compatible serial support
   SLIP_COMPRESSED y # CSLIP compressed headers
@@ -369,6 +357,9 @@ with stdenv.lib;
   ''}
   USB_EHCI_ROOT_HUB_TT y # Root Hub Transaction Translators
   USB_EHCI_TT_NEWSCHED y # Improved transaction translator scheduling
+  ${optionalString (versionAtLeast version "4.3") ''
+    USERFAULTFD y
+  ''}
   X86_CHECK_BIOS_CORRUPTION y
   X86_MCE y
 
@@ -379,16 +370,14 @@ with stdenv.lib;
   NAMESPACES? y #  Required by 'unshare' used by 'nixos-install'
   RT_GROUP_SCHED? y
   CGROUP_DEVICE? y
-  ${if versionAtLeast version "3.6" then ''
-    MEMCG y
-    MEMCG_SWAP y
-  '' else ''
-    CGROUP_MEM_RES_CTLR y
-    CGROUP_MEM_RES_CTLR_SWAP y
-  ''}
+  MEMCG y
+  MEMCG_SWAP y
   ${optionalString (versionOlder version "4.7") "DEVPTS_MULTIPLE_INSTANCES y"}
   BLK_DEV_THROTTLING y
   CFQ_GROUP_IOSCHED y
+  ${optionalString (versionAtLeast version "4.3") ''
+    CGROUP_PIDS y
+  ''}
 
   # Enable staging drivers.  These are somewhat experimental, but
   # they generally don't hurt.
@@ -406,9 +395,7 @@ with stdenv.lib;
   FTRACE_SYSCALLS y
   SCHED_TRACER y
   STACK_TRACER y
-  ${optionalString (versionAtLeast version "3.10") ''
-    UPROBE_EVENT y
-  ''}
+  UPROBE_EVENT y
   ${optionalString (versionAtLeast version "4.4") ''
     BPF_SYSCALL y
     BPF_EVENTS y
@@ -420,28 +407,18 @@ with stdenv.lib;
   DEVTMPFS y
 
   # Easier debugging of NFS issues.
-  ${optionalString (versionAtLeast version "3.4") ''
-    SUNRPC_DEBUG y
-  ''}
+  SUNRPC_DEBUG y
 
   # Virtualisation.
   PARAVIRT? y
-  ${if versionAtLeast version "3.10" then ''
-    HYPERVISOR_GUEST y
-  '' else ''
-    PARAVIRT_GUEST? y
-  ''}
+  HYPERVISOR_GUEST y
+  PARAVIRT_SPINLOCKS? y
   KVM_APIC_ARCHITECTURE y
   KVM_ASYNC_PF y
-  ${optionalString (versionOlder version "3.7") ''
-    KVM_CLOCK? y
-  ''}
   ${optionalString (versionAtLeast version "4.0") ''
     KVM_COMPAT? y
   ''}
-  ${optionalString (versionAtLeast version "3.10") ''
-    KVM_DEVICE_ASSIGNMENT? y
-  ''}
+  KVM_DEVICE_ASSIGNMENT? y
   ${optionalString (versionAtLeast version "4.0") ''
     KVM_GENERIC_DIRTYLOG_READ_PROTECT y
   ''}
@@ -476,28 +453,22 @@ with stdenv.lib;
   ${optionalString (!stdenv.is64bit) ''
     HIGHMEM64G? y # We need 64 GB (PAE) support for Xen guest support.
   ''}
-  ${optionalString (versionAtLeast version "3.9" && stdenv.is64bit) ''
+  ${optionalString (stdenv.is64bit) ''
     VFIO_PCI_VGA y
   ''}
   VIRT_DRIVERS y
 
   # Media support.
-  ${optionalString (versionAtLeast version "3.6") ''
-    MEDIA_DIGITAL_TV_SUPPORT y
-    MEDIA_CAMERA_SUPPORT y
-    MEDIA_RC_SUPPORT y
-  ''}
-  ${optionalString (versionAtLeast version "3.7") ''
-    MEDIA_USB_SUPPORT y
-    ${optionalString (!(features.chromiumos or false)) ''
-      MEDIA_PCI_SUPPORT y
-    ''}
+  MEDIA_DIGITAL_TV_SUPPORT y
+  MEDIA_CAMERA_SUPPORT y
+  MEDIA_RC_SUPPORT y
+  MEDIA_USB_SUPPORT y
+  ${optionalString (!(features.chromiumos or false)) ''
+    MEDIA_PCI_SUPPORT y
   ''}
 
   # Our initrd init uses shebang scripts, so can't be modular.
-  ${optionalString (versionAtLeast version "3.10") ''
-    BINFMT_SCRIPT y
-  ''}
+  BINFMT_SCRIPT y
 
   # For systemd-binfmt
   BINFMT_MISC? y
@@ -512,10 +483,9 @@ with stdenv.lib;
   TRANSPARENT_HUGEPAGE_MADVISE? y
 
   # zram support (e.g for in-memory compressed swap).
-  ${optionalString (versionAtLeast version "3.4") ''
-    ZSMALLOC y
-  ''}
+  ZSMALLOC y
   ZRAM m
+  ZSWAP y
 
   # Enable PCIe and USB for the brcmfmac driver
   BRCMFMAC_USB? y