diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 150 |
1 files changed, 112 insertions, 38 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index d9c171ce4190..6571fbfdb2a1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -314,7 +314,7 @@ amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: <a>,<b> - See also Documentation/input/joystick.txt + See also Documentation/input/joydev/joystick.rst analog.map= [HW,JOY] Analog joystick and gamepad support Specifies type or capabilities of an analog joystick @@ -439,7 +439,7 @@ bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) bttv.radio= Most important insmod options are available as kernel args too. - bttv.pll= See Documentation/video4linux/bttv/Insmod-options + bttv.pll= See Documentation/media/v4l-drivers/bttv.rst bttv.tuner= bulk_remove=off [PPC] This parameter disables the use of the pSeries @@ -641,8 +641,8 @@ For now, only VisioBraille is supported. consoleblank= [KNL] The console blank (screen saver) timeout in - seconds. Defaults to 10*60 = 10mins. A value of 0 - disables the blank timer. + seconds. A value of 0 disables the blank timer. + Defaults to 0. coredump_filter= [KNL] Change the default value for @@ -709,6 +709,9 @@ It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. + crossrelease_fullstack + [KNL] Allow to record full stack trace in cross-release + cryptomgr.notests [KNL] Disable crypto self-tests @@ -724,7 +727,7 @@ db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port (one device per port) Format: <port#>,<type> - See also Documentation/input/joystick-parport.txt + See also Documentation/input/devices/joystick-parport.rst ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot time. See @@ -854,7 +857,7 @@ The filter can be disabled or changed to another driver later using sysfs. - drm_kms_helper.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>] + drm.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>] Broken monitors, graphic adapters, KVMs and EDIDless panels may send no or incorrect EDID data sets. This parameter allows to specify an EDID data sets @@ -1220,7 +1223,7 @@ [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port) Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5> - See also Documentation/input/joystick-parport.txt + See also Documentation/input/devices/joystick-parport.rst gamma= [HW,DRM] @@ -1713,6 +1716,13 @@ irqaffinity= [SMP] Set the default irq affinity mask The argument is a cpu list, as described above. + irqchip.gicv2_force_probe= + [ARM, ARM64] + Format: <bool> + Force the kernel to look for the second 4kB page + of a GICv2 controller even if the memory range + exposed by the device tree is too small. + irqfixup [HW] When an interrupt is not handled search all handlers for it. Intended to get systems with badly broken @@ -1727,20 +1737,33 @@ isapnp= [ISAPNP] Format: <RDP>,<reset>,<pci_scan>,<verbosity> - isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. - The argument is a cpu list, as described above. + isolcpus= [KNL,SMP] Isolate a given set of CPUs from disturbance. + [Deprecated - use cpusets instead] + Format: [flag-list,]<cpu-list> + + Specify one or more CPUs to isolate from disturbances + specified in the flag list (default: domain): + + nohz + Disable the tick when a single task runs. + domain + Isolate from the general SMP balancing and scheduling + algorithms. Note that performing domain isolation this way + is irreversible: it's not possible to bring back a CPU to + the domains once isolated through isolcpus. It's strongly + advised to use cpusets instead to disable scheduler load + balancing through the "cpuset.sched_load_balance" file. + It offers a much more flexible interface where CPUs can + move in and out of an isolated set anytime. + + You can move a process onto or off an "isolated" CPU via + the CPU affinity syscalls or cpuset. + <cpu number> begins at 0 and the maximum value is + "number of CPUs in system - 1". + + The format of <cpu-list> is described above. - This option can be used to specify one or more CPUs - to isolate from the general SMP balancing and scheduling - algorithms. You can move a process onto or off an - "isolated" CPU via the CPU affinity syscalls or cpuset. - <cpu number> begins at 0 and the maximum value is - "number of CPUs in system - 1". - This option is the preferred way to isolate CPUs. The - alternative -- manually setting the CPU mask of all - tasks in the system -- can cause problems and - suboptimal load balancer performance. iucv= [HW,NET] @@ -1766,7 +1789,7 @@ ivrs_acpihid[00:14.5]=AMD0020:0 js= [HW,JOY] Analog joystick - See Documentation/input/joystick.txt. + See Documentation/input/joydev/joystick.rst. nokaslr [KNL] When CONFIG_RANDOMIZE_BASE is set, this disables @@ -1841,13 +1864,6 @@ Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, the default is off. - kmemcheck= [X86] Boot-time kmemcheck enable/disable/one-shot mode - Valid arguments: 0, 1, 2 - kmemcheck=0 (disabled) - kmemcheck=1 (enabled) - kmemcheck=2 (one-shot mode) - Default: 2 (one-shot mode) - kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. Default is 0 (don't ignore, but inject #GP) @@ -1874,6 +1890,10 @@ [KVM,ARM] Trap guest accesses to GICv3 common system registers + kvm-arm.vgic_v4_enable= + [KVM,ARM] Allow use of GICv4 for direct injection of + LPIs. + kvm-intel.ept= [KVM,Intel] Disable extended page tables (virtualized MMU) support on capable Intel chips. Default is 1 (enabled) @@ -2233,14 +2253,25 @@ memory contents and reserves bad memory regions that are detected. + mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control + Valid arguments: on, off + Default (depends on kernel configuration option): + on (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y) + off (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=n) + mem_encrypt=on: Activate SME + mem_encrypt=off: Do not activate SME + + Refer to Documentation/x86/amd-memory-encryption.txt + for details on when memory encryption can be activated. + mem_sleep_default= [SUSPEND] Default system suspend mode: s2idle - Suspend-To-Idle shallow - Power-On Suspend or equivalent (if supported) deep - Suspend-To-RAM or equivalent (if supported) - See Documentation/power/states.txt. + See Documentation/admin-guide/pm/sleep-states.rst. meye.*= [HW] Set MotionEye Camera parameters - See Documentation/video4linux/meye.txt. + See Documentation/media/v4l-drivers/meye.rst. mfgpt_irq= [IA-32] Specify the IRQ to use for the Multi-Function General Purpose Timers on AMD Geode @@ -2537,6 +2568,9 @@ noalign [KNL,ARM] + noaltinstr [S390] Disables alternative instructions patching + (CPU alternatives feature). + noapic [SMP,APIC] Tells the kernel to not make use of any IOAPICs that may be present in the system. @@ -2633,9 +2667,10 @@ In kernels built with CONFIG_NO_HZ_FULL=y, set the specified list of CPUs whose tick will be stopped whenever possible. The boot CPU will be forced outside - the range to maintain the timekeeping. - The CPUs in this range must also be included in the - rcu_nocbs= set. + the range to maintain the timekeeping. Any CPUs + in this list will have their RCU callbacks offloaded, + just as if they had also been called out in the + rcu_nocbs= boot parameter. noiotrap [SH] Disables trapped I/O port accesses. @@ -2696,6 +2731,8 @@ nopat [X86] Disable PAT (page attribute table extension of pagetables) support. + nopcid [X86-64] Disable the PCID cpu feature. + norandmaps Don't use address space randomization. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space @@ -2750,6 +2787,15 @@ If the dependencies are under your control, you can turn on cpu0_hotplug. + nps_mtm_hs_ctr= [KNL,ARC] + This parameter sets the maximum duration, in + cycles, each HW thread of the CTOP can run + without interruptions, before HW switches it. + The actual maximum duration is 16 times this + parameter's value. + Format: integer between 1 and 255 + Default: 255 + nptcg= [IA-64] Override max number of concurrent global TLB purges which is reported from either PAL_VM_SUMMARY or SAL PALO. @@ -2769,7 +2815,7 @@ Allowed values are enable and disable numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. - one of ['zone', 'node', 'default'] can be specified + 'node', 'default' can be specified This can be set from sysctl after boot. See Documentation/sysctl/vm.txt for details. @@ -3111,7 +3157,7 @@ plip= [PPT,NET] Parallel port network link Format: { parport<nr> | timid | 0 } - See also Documentation/parport.txt. + See also Documentation/admin-guide/parport.rst. pmtmr= [X86] Manual setup of pmtmr I/O Port. Override pmtimer IOPort with a hex value. @@ -3162,6 +3208,10 @@ allowed (eg kernel_enable_fpu()/kernel_disable_fpu()). There is some performance impact when enabling this. + ppc_tm= [PPC] + Format: {"off"} + Disable Hardware Transactional Memory + print-fatal-signals= [KNL] debug: print fatal signals @@ -3200,13 +3250,15 @@ instead using the legacy FADT method profile= [KNL] Enable kernel profiling via /proc/profile - Format: [schedule,]<number> + Format: [<profiletype>,]<number> + Param: <profiletype>: "schedule", "sleep", or "kvm" + [defaults to kernel profiling] Param: "schedule" - profile schedule points. - Param: <number> - step/bucket size as a power of 2 for - statistical time based profiling. Param: "sleep" - profile D-state sleeping (millisecs). Requires CONFIG_SCHEDSTATS Param: "kvm" - profile VM exits. + Param: <number> - step/bucket size as a power of 2 for + statistical time based profiling. prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk before loading. @@ -3516,6 +3568,9 @@ rcutorture.stall_cpu_holdoff= [KNL] Time to wait (s) after boot before inducing stall. + rcutorture.stall_cpu_irqsoff= [KNL] + Disable interrupts while stalling if set. + rcutorture.stat_interval= [KNL] Time (s) between statistics printk()s. @@ -3598,6 +3653,12 @@ Run specified binary instead of /init from the ramdisk, used for early userspace startup. See initrd. + rdt= [HW,X86,RDT] + Turn on/off individual RDT features. List is: + cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, mba. + E.g. to turn on cmt and turn off mba use: + rdt=cmt,!mba + reboot= [KNL] Format (x86 or x86_64): [w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \ @@ -3856,6 +3917,12 @@ [KNL] Should the soft-lockup detector generate panics. Format: <integer> + A nonzero value instructs the soft-lockup detector + to panic the machine when a soft-lockup occurs. This + is also controlled by CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC + which is the respective build-time switch to that + functionality. + softlockup_all_cpu_backtrace= [KNL] Should the soft-lockup detector generate backtraces on all cpus. @@ -4165,12 +4232,15 @@ Used to run time disable IRQ_TIME_ACCOUNTING on any platforms where RDTSC is slow and this accounting can add overhead. + [x86] unstable: mark the TSC clocksource as unstable, this + marks the TSC unconditionally unstable at bootup and + avoids any further wobbles once the TSC watchdog notices. turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface Format: <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> - See also Documentation/input/joystick-parport.txt + See also Documentation/input/devices/joystick-parport.rst udbg-immortal [PPC] When debugging early kernel crashes that happen after console_init() and before a proper @@ -4375,6 +4445,10 @@ decrease the size and leave more room for directly mapped kernel RAM. + vmcp_cma=nn[MG] [KNL,S390] + Sets the memory size reserved for contiguous memory + allocations for the vmcp device driver. + vmhalt= [KNL,S390] Perform z/VM CP command after system halt. Format: <command> |
