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notes:kernel_parameters

Information

  • Kernel parameters that were useful at some point in time

Old GRUB Settings

  • :!: Use grubby instead unless it doesn't exist by-default

UEFI

sudo -e '/etc/default/grub' && sudo grub2-mkconfig -o '/boot/efi/EFI/fedora/grub.cfg'

Legacy

sudo -e '/etc/default/grub' && sudo grub2-mkconfig -o '/boot/grub2/grub.cfg'

Kernel Options

blk_mq

  • I think the kernel at some point removed non-blk schedulers, so this isn't necessary
scsi_mod.use_blk_mq=y dm_mod.use_blk_mq=y

Corsair USB Quirks

Blacklist Watchdogs

  • iTCO_wdt controls watchdog on some Intel platforms
  • sp5100_tco controls watchdog on some AMD platforms
  • nowatchdog disables both soft and hard generic watchdogs
  • Apparently this reduces power usage slightly
modprobe.blacklist=iTCO_wdt,sp5100_tco nowatchdog

Microcode and Security Patches

spectre_v2=off nopti

Modern Standby

  • Use S0 to suspend and wake quickly on supported systems
  • On a Dell XPS 13 9360, this used to be required, but the default deep option also works
mem_sleep_default=s2idle

dyntick-idle Disable

nohz=on

intel_iommu

intel_iommu=on

i915

  • GuC firmware loading/submission requires PAVP to be enabled in BIOS
  • enable_guc nor enable_psr work on a Lenovo T500 ThinkPad
i915.enable_psr=1
i915.enable_guc=3

radeon

radeon.deep_color=1

Backlight

systemd.restore_state=0

DRM Debug

  • :!: This may make lower-end machines become very unresponsive; be prepared to have some safe way of rebooting
drm.debug=0xe

Reboot

  • efi is for UEFI systems
  • pci is for Legacy systems and Coreboot with SeaBIOS payload
  • There are other values possible should either of those not work
reboot=pci
reboot=efi

Custom Resolution

for p in /sys/class/drm/*/status; do con=${p%/status}; echo -n "${con#*/card?-}: "; cat $p; done
video=HDMI-A-1:3840x2160MR@59
notes/kernel_parameters.txt · Last modified: 2019/11/17 14:48 by Sean Rhone