| kernel-parameters.txt (9eb124fe796cbadd454c8f946d7051f4c3f4a251) | kernel-parameters.txt (aa8c6248f8c75acfd610fe15d8cae23cf70d9d09) |
|---|---|
| 1 acpi= [HW,ACPI,X86,ARM64] 2 Advanced Configuration and Power Interface 3 Format: { force | on | off | strict | noirq | rsdt | 4 copy_dsdt } 5 force -- enable ACPI if default was off 6 on -- enable ACPI but allow fallback to DT [arm64] 7 off -- disable ACPI if default was on 8 noirq -- do not use ACPI for IRQ routing --- 300 unchanged lines hidden (view full) --- 309 vapic - Use virtual APIC mode, which allows IOMMU 310 to inject interrupts directly into guest. 311 This mode requires kvm-amd.avic=1. 312 (Default when IOMMU HW support is present.) 313 314 amijoy.map= [HW,JOY] Amiga joystick support 315 Map of devices attached to JOY0DAT and JOY1DAT 316 Format: <a>,<b> | 1 acpi= [HW,ACPI,X86,ARM64] 2 Advanced Configuration and Power Interface 3 Format: { force | on | off | strict | noirq | rsdt | 4 copy_dsdt } 5 force -- enable ACPI if default was off 6 on -- enable ACPI but allow fallback to DT [arm64] 7 off -- disable ACPI if default was on 8 noirq -- do not use ACPI for IRQ routing --- 300 unchanged lines hidden (view full) --- 309 vapic - Use virtual APIC mode, which allows IOMMU 310 to inject interrupts directly into guest. 311 This mode requires kvm-amd.avic=1. 312 (Default when IOMMU HW support is present.) 313 314 amijoy.map= [HW,JOY] Amiga joystick support 315 Map of devices attached to JOY0DAT and JOY1DAT 316 Format: <a>,<b> |
| 317 See also Documentation/input/joydev/joystick.rst | 317 See also Documentation/input/joystick.txt |
| 318 319 analog.map= [HW,JOY] Analog joystick and gamepad support 320 Specifies type or capabilities of an analog joystick 321 connected to one of 16 gameports 322 Format: <type1>,<type2>,..<type16> 323 324 apc= [HW,SPARC] 325 Power management functions (SPARCstation-4/5 + deriv.) --- 108 unchanged lines hidden (view full) --- 434 bootmem_debug [KNL] Enable bootmem allocator debug messages. 435 436 bert_disable [ACPI] 437 Disable BERT OS support on buggy BIOSes. 438 439 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) 440 bttv.radio= Most important insmod options are available as 441 kernel args too. | 318 319 analog.map= [HW,JOY] Analog joystick and gamepad support 320 Specifies type or capabilities of an analog joystick 321 connected to one of 16 gameports 322 Format: <type1>,<type2>,..<type16> 323 324 apc= [HW,SPARC] 325 Power management functions (SPARCstation-4/5 + deriv.) --- 108 unchanged lines hidden (view full) --- 434 bootmem_debug [KNL] Enable bootmem allocator debug messages. 435 436 bert_disable [ACPI] 437 Disable BERT OS support on buggy BIOSes. 438 439 bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) 440 bttv.radio= Most important insmod options are available as 441 kernel args too. |
| 442 bttv.pll= See Documentation/media/v4l-drivers/bttv.rst | 442 bttv.pll= See Documentation/video4linux/bttv/Insmod-options |
| 443 bttv.tuner= 444 445 bulk_remove=off [PPC] This parameter disables the use of the pSeries 446 firmware feature for flushing multiple hpte entries 447 at a time. 448 449 c101= [NET] Moxa C101 synchronous serial card 450 --- 185 unchanged lines hidden (view full) --- 636 both Xen and PowerPC hypervisors. 637 638 If the device connected to the port is not a TTY but a braille 639 device, prepend "brl," before the device type, for instance 640 console=brl,ttyS0 641 For now, only VisioBraille is supported. 642 643 consoleblank= [KNL] The console blank (screen saver) timeout in | 443 bttv.tuner= 444 445 bulk_remove=off [PPC] This parameter disables the use of the pSeries 446 firmware feature for flushing multiple hpte entries 447 at a time. 448 449 c101= [NET] Moxa C101 synchronous serial card 450 --- 185 unchanged lines hidden (view full) --- 636 both Xen and PowerPC hypervisors. 637 638 If the device connected to the port is not a TTY but a braille 639 device, prepend "brl," before the device type, for instance 640 console=brl,ttyS0 641 For now, only VisioBraille is supported. 642 643 consoleblank= [KNL] The console blank (screen saver) timeout in |
| 644 seconds. A value of 0 disables the blank timer. 645 Defaults to 0. | 644 seconds. Defaults to 10*60 = 10mins. A value of 0 645 disables the blank timer. |
| 646 647 coredump_filter= 648 [KNL] Change the default value for 649 /proc/<pid>/coredump_filter. 650 See also Documentation/filesystems/proc.txt. 651 652 coresight_cpu_debug.enable 653 [ARM,ARM64] --- 50 unchanged lines hidden (view full) --- 704 devices won't run out. Kernel would try to allocate at 705 at least 256M below 4G automatically. 706 This one let user to specify own low range under 4G 707 for second kernel instead. 708 0: to disable low allocation. 709 It will be ignored when crashkernel=X,high is not used 710 or memory reserved is below 4G. 711 | 646 647 coredump_filter= 648 [KNL] Change the default value for 649 /proc/<pid>/coredump_filter. 650 See also Documentation/filesystems/proc.txt. 651 652 coresight_cpu_debug.enable 653 [ARM,ARM64] --- 50 unchanged lines hidden (view full) --- 704 devices won't run out. Kernel would try to allocate at 705 at least 256M below 4G automatically. 706 This one let user to specify own low range under 4G 707 for second kernel instead. 708 0: to disable low allocation. 709 It will be ignored when crashkernel=X,high is not used 710 or memory reserved is below 4G. 711 |
| 712 crossrelease_fullstack 713 [KNL] Allow to record full stack trace in cross-release 714 | |
| 715 cryptomgr.notests 716 [KNL] Disable crypto self-tests 717 718 cs89x0_dma= [HW,NET] 719 Format: <dma> 720 721 cs89x0_media= [HW,NET] 722 Format: { rj45 | aui | bnc } 723 724 dasd= [HW,NET] 725 See header of drivers/s390/block/dasd_devmap.c. 726 727 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port 728 (one device per port) 729 Format: <port#>,<type> | 712 cryptomgr.notests 713 [KNL] Disable crypto self-tests 714 715 cs89x0_dma= [HW,NET] 716 Format: <dma> 717 718 cs89x0_media= [HW,NET] 719 Format: { rj45 | aui | bnc } 720 721 dasd= [HW,NET] 722 See header of drivers/s390/block/dasd_devmap.c. 723 724 db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port 725 (one device per port) 726 Format: <port#>,<type> |
| 730 See also Documentation/input/devices/joystick-parport.rst | 727 See also Documentation/input/joystick-parport.txt |
| 731 732 ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot 733 time. See 734 Documentation/admin-guide/dynamic-debug-howto.rst for 735 details. Deprecated, see dyndbg. 736 737 debug [KNL] Enable kernel debugging (events log level). 738 --- 113 unchanged lines hidden (view full) --- 852 853 dma_debug_driver=<driver_name> 854 With this option the DMA-API debugging driver 855 filter feature can be enabled at boot time. Just 856 pass the driver to filter for as the parameter. 857 The filter can be disabled or changed to another 858 driver later using sysfs. 859 | 728 729 ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot 730 time. See 731 Documentation/admin-guide/dynamic-debug-howto.rst for 732 details. Deprecated, see dyndbg. 733 734 debug [KNL] Enable kernel debugging (events log level). 735 --- 113 unchanged lines hidden (view full) --- 849 850 dma_debug_driver=<driver_name> 851 With this option the DMA-API debugging driver 852 filter feature can be enabled at boot time. Just 853 pass the driver to filter for as the parameter. 854 The filter can be disabled or changed to another 855 driver later using sysfs. 856 |
| 860 drm.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>] | 857 drm_kms_helper.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>] |
| 861 Broken monitors, graphic adapters, KVMs and EDIDless 862 panels may send no or incorrect EDID data sets. 863 This parameter allows to specify an EDID data sets 864 in the /lib/firmware directory that are used instead. 865 Generic built-in EDID data sets are used, if one of 866 edid/1024x768.bin, edid/1280x1024.bin, 867 edid/1680x1050.bin, or edid/1920x1080.bin is given 868 and no file with the same name exists. Details and --- 349 unchanged lines hidden (view full) --- 1218 the max depth it will trace into a function. This value 1219 can be changed at run time by the max_graph_depth file 1220 in the tracefs tracing directory. default: 0 (no limit) 1221 1222 gamecon.map[2|3]= 1223 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad 1224 support via parallel port (up to 5 devices per port) 1225 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> | 858 Broken monitors, graphic adapters, KVMs and EDIDless 859 panels may send no or incorrect EDID data sets. 860 This parameter allows to specify an EDID data sets 861 in the /lib/firmware directory that are used instead. 862 Generic built-in EDID data sets are used, if one of 863 edid/1024x768.bin, edid/1280x1024.bin, 864 edid/1680x1050.bin, or edid/1920x1080.bin is given 865 and no file with the same name exists. Details and --- 349 unchanged lines hidden (view full) --- 1215 the max depth it will trace into a function. This value 1216 can be changed at run time by the max_graph_depth file 1217 in the tracefs tracing directory. default: 0 (no limit) 1218 1219 gamecon.map[2|3]= 1220 [HW,JOY] Multisystem joystick and NES/SNES/PSX pad 1221 support via parallel port (up to 5 devices per port) 1222 Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> |
| 1226 See also Documentation/input/devices/joystick-parport.rst | 1223 See also Documentation/input/joystick-parport.txt |
| 1227 1228 gamma= [HW,DRM] 1229 1230 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART 1231 Format: off | on 1232 default: on 1233 1234 gcov_persist= [GCOV] When non-zero (default), profiling data for --- 476 unchanged lines hidden (view full) --- 1711 No delay 1712 1713 ip= [IP_PNP] 1714 See Documentation/filesystems/nfs/nfsroot.txt. 1715 1716 irqaffinity= [SMP] Set the default irq affinity mask 1717 The argument is a cpu list, as described above. 1718 | 1224 1225 gamma= [HW,DRM] 1226 1227 gart_fix_e820= [X86_64] disable the fix e820 for K8 GART 1228 Format: off | on 1229 default: on 1230 1231 gcov_persist= [GCOV] When non-zero (default), profiling data for --- 476 unchanged lines hidden (view full) --- 1708 No delay 1709 1710 ip= [IP_PNP] 1711 See Documentation/filesystems/nfs/nfsroot.txt. 1712 1713 irqaffinity= [SMP] Set the default irq affinity mask 1714 The argument is a cpu list, as described above. 1715 |
| 1719 irqchip.gicv2_force_probe= 1720 [ARM, ARM64] 1721 Format: <bool> 1722 Force the kernel to look for the second 4kB page 1723 of a GICv2 controller even if the memory range 1724 exposed by the device tree is too small. 1725 | |
| 1726 irqfixup [HW] 1727 When an interrupt is not handled search all handlers 1728 for it. Intended to get systems with badly broken 1729 firmware running. 1730 1731 irqpoll [HW] 1732 When an interrupt is not handled search all handlers 1733 for it. Also check all handlers each timer 1734 interrupt. Intended to get systems with badly broken 1735 firmware running. 1736 1737 isapnp= [ISAPNP] 1738 Format: <RDP>,<reset>,<pci_scan>,<verbosity> 1739 | 1716 irqfixup [HW] 1717 When an interrupt is not handled search all handlers 1718 for it. Intended to get systems with badly broken 1719 firmware running. 1720 1721 irqpoll [HW] 1722 When an interrupt is not handled search all handlers 1723 for it. Also check all handlers each timer 1724 interrupt. Intended to get systems with badly broken 1725 firmware running. 1726 1727 isapnp= [ISAPNP] 1728 Format: <RDP>,<reset>,<pci_scan>,<verbosity> 1729 |
| 1740 isolcpus= [KNL,SMP] Isolate a given set of CPUs from disturbance. 1741 [Deprecated - use cpusets instead] 1742 Format: [flag-list,]<cpu-list> | 1730 isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. 1731 The argument is a cpu list, as described above. |
| 1743 | 1732 |
| 1744 Specify one or more CPUs to isolate from disturbances 1745 specified in the flag list (default: domain): | 1733 This option can be used to specify one or more CPUs 1734 to isolate from the general SMP balancing and scheduling 1735 algorithms. You can move a process onto or off an 1736 "isolated" CPU via the CPU affinity syscalls or cpuset. 1737 <cpu number> begins at 0 and the maximum value is 1738 "number of CPUs in system - 1". |
| 1746 | 1739 |
| 1747 nohz 1748 Disable the tick when a single task runs. 1749 domain 1750 Isolate from the general SMP balancing and scheduling 1751 algorithms. Note that performing domain isolation this way 1752 is irreversible: it's not possible to bring back a CPU to 1753 the domains once isolated through isolcpus. It's strongly 1754 advised to use cpusets instead to disable scheduler load 1755 balancing through the "cpuset.sched_load_balance" file. 1756 It offers a much more flexible interface where CPUs can 1757 move in and out of an isolated set anytime. | 1740 This option is the preferred way to isolate CPUs. The 1741 alternative -- manually setting the CPU mask of all 1742 tasks in the system -- can cause problems and 1743 suboptimal load balancer performance. |
| 1758 | 1744 |
| 1759 You can move a process onto or off an "isolated" CPU via 1760 the CPU affinity syscalls or cpuset. 1761 <cpu number> begins at 0 and the maximum value is 1762 "number of CPUs in system - 1". 1763 1764 The format of <cpu-list> is described above. 1765 1766 1767 | |
| 1768 iucv= [HW,NET] 1769 1770 ivrs_ioapic [HW,X86_64] 1771 Provide an override to the IOAPIC-ID<->DEVICE-ID 1772 mapping provided in the IVRS ACPI table. For 1773 example, to map IOAPIC-ID decimal 10 to 1774 PCI device 00:14.0 write the parameter as: 1775 ivrs_ioapic[10]=00:14.0 --- 8 unchanged lines hidden (view full) --- 1784 ivrs_acpihid [HW,X86_64] 1785 Provide an override to the ACPI-HID:UID<->DEVICE-ID 1786 mapping provided in the IVRS ACPI table. For 1787 example, to map UART-HID:UID AMD0020:0 to 1788 PCI device 00:14.5 write the parameter as: 1789 ivrs_acpihid[00:14.5]=AMD0020:0 1790 1791 js= [HW,JOY] Analog joystick | 1745 iucv= [HW,NET] 1746 1747 ivrs_ioapic [HW,X86_64] 1748 Provide an override to the IOAPIC-ID<->DEVICE-ID 1749 mapping provided in the IVRS ACPI table. For 1750 example, to map IOAPIC-ID decimal 10 to 1751 PCI device 00:14.0 write the parameter as: 1752 ivrs_ioapic[10]=00:14.0 --- 8 unchanged lines hidden (view full) --- 1761 ivrs_acpihid [HW,X86_64] 1762 Provide an override to the ACPI-HID:UID<->DEVICE-ID 1763 mapping provided in the IVRS ACPI table. For 1764 example, to map UART-HID:UID AMD0020:0 to 1765 PCI device 00:14.5 write the parameter as: 1766 ivrs_acpihid[00:14.5]=AMD0020:0 1767 1768 js= [HW,JOY] Analog joystick |
| 1792 See Documentation/input/joydev/joystick.rst. | 1769 See Documentation/input/joystick.txt. |
| 1793 1794 nokaslr [KNL] 1795 When CONFIG_RANDOMIZE_BASE is set, this disables 1796 kernel and module base offset ASLR (Address Space 1797 Layout Randomization). 1798 1799 kasan_multi_shot 1800 [KNL] Enforce KASAN (Kernel Address Sanitizer) to print --- 58 unchanged lines hidden (view full) --- 1859 Ethernet adapter MAC address. 1860 1861 kmemleak= [KNL] Boot-time kmemleak enable/disable 1862 Valid arguments: on, off 1863 Default: on 1864 Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, 1865 the default is off. 1866 | 1770 1771 nokaslr [KNL] 1772 When CONFIG_RANDOMIZE_BASE is set, this disables 1773 kernel and module base offset ASLR (Address Space 1774 Layout Randomization). 1775 1776 kasan_multi_shot 1777 [KNL] Enforce KASAN (Kernel Address Sanitizer) to print --- 58 unchanged lines hidden (view full) --- 1836 Ethernet adapter MAC address. 1837 1838 kmemleak= [KNL] Boot-time kmemleak enable/disable 1839 Valid arguments: on, off 1840 Default: on 1841 Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, 1842 the default is off. 1843 |
| 1844 kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode 1845 Valid arguments: 0, 1, 2 1846 kmemcheck=0 (disabled) 1847 kmemcheck=1 (enabled) 1848 kmemcheck=2 (one-shot mode) 1849 Default: 2 (one-shot mode) 1850 |
|
| 1867 kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. 1868 Default is 0 (don't ignore, but inject #GP) 1869 1870 kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit 1871 KVM MMU at runtime. 1872 Default is 0 (off) 1873 1874 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. --- 10 unchanged lines hidden (view full) --- 1885 kvm-arm.vgic_v3_group1_trap= 1886 [KVM,ARM] Trap guest accesses to GICv3 group-1 1887 system registers 1888 1889 kvm-arm.vgic_v3_common_trap= 1890 [KVM,ARM] Trap guest accesses to GICv3 common 1891 system registers 1892 | 1851 kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. 1852 Default is 0 (don't ignore, but inject #GP) 1853 1854 kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit 1855 KVM MMU at runtime. 1856 Default is 0 (off) 1857 1858 kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. --- 10 unchanged lines hidden (view full) --- 1869 kvm-arm.vgic_v3_group1_trap= 1870 [KVM,ARM] Trap guest accesses to GICv3 group-1 1871 system registers 1872 1873 kvm-arm.vgic_v3_common_trap= 1874 [KVM,ARM] Trap guest accesses to GICv3 common 1875 system registers 1876 |
| 1893 kvm-arm.vgic_v4_enable= 1894 [KVM,ARM] Allow use of GICv4 for direct injection of 1895 LPIs. 1896 | |
| 1897 kvm-intel.ept= [KVM,Intel] Disable extended page tables 1898 (virtualized MMU) support on capable Intel chips. 1899 Default is 1 (enabled) 1900 1901 kvm-intel.emulate_invalid_guest_state= 1902 [KVM,Intel] Enable emulation of invalid guest states 1903 Default is 0 (disabled) 1904 --- 358 unchanged lines hidden (view full) --- 2263 2264 Refer to Documentation/x86/amd-memory-encryption.txt 2265 for details on when memory encryption can be activated. 2266 2267 mem_sleep_default= [SUSPEND] Default system suspend mode: 2268 s2idle - Suspend-To-Idle 2269 shallow - Power-On Suspend or equivalent (if supported) 2270 deep - Suspend-To-RAM or equivalent (if supported) | 1877 kvm-intel.ept= [KVM,Intel] Disable extended page tables 1878 (virtualized MMU) support on capable Intel chips. 1879 Default is 1 (enabled) 1880 1881 kvm-intel.emulate_invalid_guest_state= 1882 [KVM,Intel] Enable emulation of invalid guest states 1883 Default is 0 (disabled) 1884 --- 358 unchanged lines hidden (view full) --- 2243 2244 Refer to Documentation/x86/amd-memory-encryption.txt 2245 for details on when memory encryption can be activated. 2246 2247 mem_sleep_default= [SUSPEND] Default system suspend mode: 2248 s2idle - Suspend-To-Idle 2249 shallow - Power-On Suspend or equivalent (if supported) 2250 deep - Suspend-To-RAM or equivalent (if supported) |
| 2271 See Documentation/admin-guide/pm/sleep-states.rst. | 2251 See Documentation/power/states.txt. |
| 2272 2273 meye.*= [HW] Set MotionEye Camera parameters | 2252 2253 meye.*= [HW] Set MotionEye Camera parameters |
| 2274 See Documentation/media/v4l-drivers/meye.rst. | 2254 See Documentation/video4linux/meye.txt. |
| 2275 2276 mfgpt_irq= [IA-32] Specify the IRQ to use for the 2277 Multi-Function General Purpose Timers on AMD Geode 2278 platforms. 2279 2280 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when 2281 the BIOS has incorrectly applied a workaround. TinyBIOS 2282 version 0.98 is known to be affected, 0.99 fixes the --- 250 unchanged lines hidden (view full) --- 2533 1 - turn hardlockup detector in nmi_watchdog on 2534 When panic is specified, panic when an NMI watchdog 2535 timeout occurs (or 'nopanic' to override the opposite 2536 default). To disable both hard and soft lockup detectors, 2537 please see 'nowatchdog'. 2538 This is useful when you use a panic=... timeout and 2539 need the box quickly up again. 2540 | 2255 2256 mfgpt_irq= [IA-32] Specify the IRQ to use for the 2257 Multi-Function General Purpose Timers on AMD Geode 2258 platforms. 2259 2260 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when 2261 the BIOS has incorrectly applied a workaround. TinyBIOS 2262 version 0.98 is known to be affected, 0.99 fixes the --- 250 unchanged lines hidden (view full) --- 2513 1 - turn hardlockup detector in nmi_watchdog on 2514 When panic is specified, panic when an NMI watchdog 2515 timeout occurs (or 'nopanic' to override the opposite 2516 default). To disable both hard and soft lockup detectors, 2517 please see 'nowatchdog'. 2518 This is useful when you use a panic=... timeout and 2519 need the box quickly up again. 2520 |
| 2541 These settings can be accessed at runtime via 2542 the nmi_watchdog and hardlockup_panic sysctls. 2543 | |
| 2544 netpoll.carrier_timeout= 2545 [NET] Specifies amount of time (in seconds) that 2546 netpoll should wait for a carrier. By default netpoll 2547 waits 4 seconds. 2548 2549 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths 2550 emulation library even if a 387 maths coprocessor 2551 is present. --- 14 unchanged lines hidden (view full) --- 2566 turn on/off it dynamically. 2567 2568 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien 2569 caches in the slab allocator. Saves per-node memory, 2570 but will impact performance. 2571 2572 noalign [KNL,ARM] 2573 | 2521 netpoll.carrier_timeout= 2522 [NET] Specifies amount of time (in seconds) that 2523 netpoll should wait for a carrier. By default netpoll 2524 waits 4 seconds. 2525 2526 no387 [BUGS=X86-32] Tells the kernel to use the 387 maths 2527 emulation library even if a 387 maths coprocessor 2528 is present. --- 14 unchanged lines hidden (view full) --- 2543 turn on/off it dynamically. 2544 2545 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien 2546 caches in the slab allocator. Saves per-node memory, 2547 but will impact performance. 2548 2549 noalign [KNL,ARM] 2550 |
| 2574 noaltinstr [S390] Disables alternative instructions patching 2575 (CPU alternatives feature). 2576 | |
| 2577 noapic [SMP,APIC] Tells the kernel to not make use of any 2578 IOAPICs that may be present in the system. 2579 2580 noautogroup Disable scheduler automatic task group creation. 2581 2582 nobats [PPC] Do not use BATs for mapping kernel lowmem 2583 on "Classic" PPC cores. 2584 --- 121 unchanged lines hidden (view full) --- 2706 no-vmw-sched-clock 2707 [X86,PV_OPS] Disable paravirtualized VMware scheduler 2708 clock and use the default one. 2709 2710 no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. 2711 steal time is computed, but won't influence scheduler 2712 behaviour 2713 | 2551 noapic [SMP,APIC] Tells the kernel to not make use of any 2552 IOAPICs that may be present in the system. 2553 2554 noautogroup Disable scheduler automatic task group creation. 2555 2556 nobats [PPC] Do not use BATs for mapping kernel lowmem 2557 on "Classic" PPC cores. 2558 --- 121 unchanged lines hidden (view full) --- 2680 no-vmw-sched-clock 2681 [X86,PV_OPS] Disable paravirtualized VMware scheduler 2682 clock and use the default one. 2683 2684 no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. 2685 steal time is computed, but won't influence scheduler 2686 behaviour 2687 |
| 2688 nopti [X86-64] Disable kernel page table isolation 2689 |
|
| 2714 nolapic [X86-32,APIC] Do not enable or use the local APIC. 2715 2716 nolapic_timer [X86-32,APIC] Do not use the local APIC timer. 2717 2718 noltlbs [PPC] Do not use large page/tlb entries for kernel 2719 lowmem mapping on PPC40x and PPC8xx 2720 2721 nomca [IA-64] Disable machine check abort handling --- 433 unchanged lines hidden (view full) --- 3155 pg. [PARIDE] 3156 See Documentation/blockdev/paride.txt. 3157 3158 pirq= [SMP,APIC] Manual mp-table setup 3159 See Documentation/x86/i386/IO-APIC.txt. 3160 3161 plip= [PPT,NET] Parallel port network link 3162 Format: { parport<nr> | timid | 0 } | 2690 nolapic [X86-32,APIC] Do not enable or use the local APIC. 2691 2692 nolapic_timer [X86-32,APIC] Do not use the local APIC timer. 2693 2694 noltlbs [PPC] Do not use large page/tlb entries for kernel 2695 lowmem mapping on PPC40x and PPC8xx 2696 2697 nomca [IA-64] Disable machine check abort handling --- 433 unchanged lines hidden (view full) --- 3131 pg. [PARIDE] 3132 See Documentation/blockdev/paride.txt. 3133 3134 pirq= [SMP,APIC] Manual mp-table setup 3135 See Documentation/x86/i386/IO-APIC.txt. 3136 3137 plip= [PPT,NET] Parallel port network link 3138 Format: { parport<nr> | timid | 0 } |
| 3163 See also Documentation/admin-guide/parport.rst. | 3139 See also Documentation/parport.txt. |
| 3164 3165 pmtmr= [X86] Manual setup of pmtmr I/O Port. 3166 Override pmtimer IOPort with a hex value. 3167 e.g. pmtmr=0x508 3168 3169 pnp.debug=1 [PNP] 3170 Enable PNP debug messages (depends on the 3171 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time --- 34 unchanged lines hidden (view full) --- 3206 execution priority. 3207 3208 ppc_strict_facility_enable 3209 [PPC] This option catches any kernel floating point, 3210 Altivec, VSX and SPE outside of regions specifically 3211 allowed (eg kernel_enable_fpu()/kernel_disable_fpu()). 3212 There is some performance impact when enabling this. 3213 | 3140 3141 pmtmr= [X86] Manual setup of pmtmr I/O Port. 3142 Override pmtimer IOPort with a hex value. 3143 e.g. pmtmr=0x508 3144 3145 pnp.debug=1 [PNP] 3146 Enable PNP debug messages (depends on the 3147 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time --- 34 unchanged lines hidden (view full) --- 3182 execution priority. 3183 3184 ppc_strict_facility_enable 3185 [PPC] This option catches any kernel floating point, 3186 Altivec, VSX and SPE outside of regions specifically 3187 allowed (eg kernel_enable_fpu()/kernel_disable_fpu()). 3188 There is some performance impact when enabling this. 3189 |
| 3214 ppc_tm= [PPC] 3215 Format: {"off"} 3216 Disable Hardware Transactional Memory 3217 | |
| 3218 print-fatal-signals= 3219 [KNL] debug: print fatal signals 3220 3221 If enabled, warn about various signal handling 3222 related application anomalies: too many signals, 3223 too many POSIX.1 timers, fatal signals causing a 3224 coredump - etc. 3225 --- 22 unchanged lines hidden (view full) --- 3248 Limit processor to maximum C-state 3249 max_cstate=9 overrides any DMI blacklist limit. 3250 3251 processor.nocst [HW,ACPI] 3252 Ignore the _CST method to determine C-states, 3253 instead using the legacy FADT method 3254 3255 profile= [KNL] Enable kernel profiling via /proc/profile | 3190 print-fatal-signals= 3191 [KNL] debug: print fatal signals 3192 3193 If enabled, warn about various signal handling 3194 related application anomalies: too many signals, 3195 too many POSIX.1 timers, fatal signals causing a 3196 coredump - etc. 3197 --- 22 unchanged lines hidden (view full) --- 3220 Limit processor to maximum C-state 3221 max_cstate=9 overrides any DMI blacklist limit. 3222 3223 processor.nocst [HW,ACPI] 3224 Ignore the _CST method to determine C-states, 3225 instead using the legacy FADT method 3226 3227 profile= [KNL] Enable kernel profiling via /proc/profile |
| 3256 Format: [<profiletype>,]<number> 3257 Param: <profiletype>: "schedule", "sleep", or "kvm" 3258 [defaults to kernel profiling] | 3228 Format: [schedule,]<number> |
| 3259 Param: "schedule" - profile schedule points. | 3229 Param: "schedule" - profile schedule points. |
| 3230 Param: <number> - step/bucket size as a power of 2 for 3231 statistical time based profiling. |
|
| 3260 Param: "sleep" - profile D-state sleeping (millisecs). 3261 Requires CONFIG_SCHEDSTATS 3262 Param: "kvm" - profile VM exits. | 3232 Param: "sleep" - profile D-state sleeping (millisecs). 3233 Requires CONFIG_SCHEDSTATS 3234 Param: "kvm" - profile VM exits. |
| 3263 Param: <number> - step/bucket size as a power of 2 for 3264 statistical time based profiling. | |
| 3265 3266 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk 3267 before loading. 3268 See Documentation/blockdev/ramdisk.txt. 3269 3270 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to 3271 probe for; one of (bare|imps|exps|lifebook|any). 3272 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports --- 293 unchanged lines hidden (view full) --- 3566 3567 rcutorture.stall_cpu= [KNL] 3568 Duration of CPU stall (s) to test RCU CPU stall 3569 warnings, zero to disable. 3570 3571 rcutorture.stall_cpu_holdoff= [KNL] 3572 Time to wait (s) after boot before inducing stall. 3573 | 3235 3236 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk 3237 before loading. 3238 See Documentation/blockdev/ramdisk.txt. 3239 3240 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to 3241 probe for; one of (bare|imps|exps|lifebook|any). 3242 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports --- 293 unchanged lines hidden (view full) --- 3536 3537 rcutorture.stall_cpu= [KNL] 3538 Duration of CPU stall (s) to test RCU CPU stall 3539 warnings, zero to disable. 3540 3541 rcutorture.stall_cpu_holdoff= [KNL] 3542 Time to wait (s) after boot before inducing stall. 3543 |
| 3574 rcutorture.stall_cpu_irqsoff= [KNL] 3575 Disable interrupts while stalling if set. 3576 | |
| 3577 rcutorture.stat_interval= [KNL] 3578 Time (s) between statistics printk()s. 3579 3580 rcutorture.stutter= [KNL] 3581 Time (s) to stutter testing, for example, specifying 3582 five seconds causes the test to run for five seconds, 3583 wait for five seconds, and so on. This tests RCU's 3584 ability to transition abruptly to and from idle. --- 330 unchanged lines hidden (view full) --- 3915 actual hardware limit. 3916 Format: <integer> 3917 Default: -1 (no limit) 3918 3919 softlockup_panic= 3920 [KNL] Should the soft-lockup detector generate panics. 3921 Format: <integer> 3922 | 3544 rcutorture.stat_interval= [KNL] 3545 Time (s) between statistics printk()s. 3546 3547 rcutorture.stutter= [KNL] 3548 Time (s) to stutter testing, for example, specifying 3549 five seconds causes the test to run for five seconds, 3550 wait for five seconds, and so on. This tests RCU's 3551 ability to transition abruptly to and from idle. --- 330 unchanged lines hidden (view full) --- 3882 actual hardware limit. 3883 Format: <integer> 3884 Default: -1 (no limit) 3885 3886 softlockup_panic= 3887 [KNL] Should the soft-lockup detector generate panics. 3888 Format: <integer> 3889 |
| 3923 A nonzero value instructs the soft-lockup detector 3924 to panic the machine when a soft-lockup occurs. This 3925 is also controlled by CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC 3926 which is the respective build-time switch to that 3927 functionality. 3928 | |
| 3929 softlockup_all_cpu_backtrace= 3930 [KNL] Should the soft-lockup detector generate 3931 backtraces on all cpus. 3932 Format: <integer> 3933 3934 sonypi.*= [HW] Sony Programmable I/O Control Device driver 3935 See Documentation/laptops/sonypi.txt 3936 --- 293 unchanged lines hidden (view full) --- 4230 disables clocksource verification at runtime, as well 4231 as the stability checks done at bootup. Used to enable 4232 high-resolution timer mode on older hardware, and in 4233 virtualized environment. 4234 [x86] noirqtime: Do not use TSC to do irq accounting. 4235 Used to run time disable IRQ_TIME_ACCOUNTING on any 4236 platforms where RDTSC is slow and this accounting 4237 can add overhead. | 3890 softlockup_all_cpu_backtrace= 3891 [KNL] Should the soft-lockup detector generate 3892 backtraces on all cpus. 3893 Format: <integer> 3894 3895 sonypi.*= [HW] Sony Programmable I/O Control Device driver 3896 See Documentation/laptops/sonypi.txt 3897 --- 293 unchanged lines hidden (view full) --- 4191 disables clocksource verification at runtime, as well 4192 as the stability checks done at bootup. Used to enable 4193 high-resolution timer mode on older hardware, and in 4194 virtualized environment. 4195 [x86] noirqtime: Do not use TSC to do irq accounting. 4196 Used to run time disable IRQ_TIME_ACCOUNTING on any 4197 platforms where RDTSC is slow and this accounting 4198 can add overhead. |
| 4238 [x86] unstable: mark the TSC clocksource as unstable, this 4239 marks the TSC unconditionally unstable at bootup and 4240 avoids any further wobbles once the TSC watchdog notices. | |
| 4241 4242 turbografx.map[2|3]= [HW,JOY] 4243 TurboGraFX parallel port interface 4244 Format: 4245 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> | 4199 4200 turbografx.map[2|3]= [HW,JOY] 4201 TurboGraFX parallel port interface 4202 Format: 4203 <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> |
| 4246 See also Documentation/input/devices/joystick-parport.rst | 4204 See also Documentation/input/joystick-parport.txt |
| 4247 4248 udbg-immortal [PPC] When debugging early kernel crashes that 4249 happen after console_init() and before a proper 4250 console driver takes over, this boot options might 4251 help "seeing" what's going on. 4252 4253 uhash_entries= [KNL,NET] 4254 Set number of hash buckets for UDP/UDP-Lite connections --- 368 unchanged lines hidden --- | 4205 4206 udbg-immortal [PPC] When debugging early kernel crashes that 4207 happen after console_init() and before a proper 4208 console driver takes over, this boot options might 4209 help "seeing" what's going on. 4210 4211 uhash_entries= [KNL,NET] 4212 Set number of hash buckets for UDP/UDP-Lite connections --- 368 unchanged lines hidden --- |