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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt109
1 files changed, 75 insertions, 34 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 05496622b4ef..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)
@@ -2248,10 +2268,10 @@
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
@@ -2548,6 +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.
@@ -3134,7 +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.
@@ -3185,6 +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
@@ -3223,13 +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.
@@ -3539,6 +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.
@@ -3885,6 +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.
@@ -4194,12 +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