summaryrefslogtreecommitdiffstats
path: root/Documentation/admin-guide/kernel-parameters.txt
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-04 12:34:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-04 12:34:27 -0700
commiteeee3149aaa022145b2659e3b0601dc705d69402 (patch)
tree1b537cccc059cab62d7d2e22b7583b192d9e8c15 /Documentation/admin-guide/kernel-parameters.txt
parentc5e7a7ea22d5677f7c70028908372cff6948ecdc (diff)
parenta49d9c0ae46e149a22aefa8251d07dddd5611851 (diff)
downloadlinux-eeee3149aaa022145b2659e3b0601dc705d69402.tar.gz
linux-eeee3149aaa022145b2659e3b0601dc705d69402.tar.bz2
linux-eeee3149aaa022145b2659e3b0601dc705d69402.zip
Merge tag 'docs-4.18' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet: "There's been a fair amount of work in the docs tree this time around, including: - Extensive RST conversions and organizational work in the memory-management docs thanks to Mike Rapoport. - An update of Documentation/features from Andrea Parri and a script to keep it updated. - Various LICENSES updates from Thomas, along with a script to check SPDX tags. - Work to fix dangling references to documentation files; this involved a fair number of one-liner comment changes outside of Documentation/ ... and the usual list of documentation improvements, typo fixes, etc" * tag 'docs-4.18' of git://git.lwn.net/linux: (103 commits) Documentation: document hung_task_panic kernel parameter docs/admin-guide/mm: add high level concepts overview docs/vm: move ksm and transhuge from "user" to "internals" section. docs: Use the kerneldoc comments for memalloc_no*() doc: document scope NOFS, NOIO APIs docs: update kernel versions and dates in tables docs/vm: transhuge: split userspace bits to admin-guide/mm/transhuge docs/vm: transhuge: minor updates docs/vm: transhuge: change sections order Documentation: arm: clean up Marvell Berlin family info Documentation: gpio: driver: Fix a typo and some odd grammar docs: ranoops.rst: fix location of ramoops.txt scripts/documentation-file-ref-check: rewrite it in perl with auto-fix mode docs: uio-howto.rst: use a code block to solve a warning mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback w1: w1_io.c: fix a kernel-doc warning Documentation/process/posting: wrap text at 80 cols docs: admin-guide: add cgroup-v2 documentation Revert "Documentation/features/vm: Remove arch support status file for 'pte_special'" Documentation: refcount-vs-atomic: Update reference to LKMM doc. ...
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt160
1 files changed, 85 insertions, 75 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index cc0ac035b8fe..b0a42f3564b6 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -106,11 +106,11 @@
use by PCI
Format: <irq>,<irq>...
- acpi_mask_gpe= [HW,ACPI]
+ acpi_mask_gpe= [HW,ACPI]
Due to the existence of _Lxx/_Exx, some GPEs triggered
by unsupported hardware/firmware features can result in
- GPE floodings that cannot be automatically disabled by
- the GPE dispatcher.
+ GPE floodings that cannot be automatically disabled by
+ the GPE dispatcher.
This facility can be used to prevent such uncontrolled
GPE floodings.
Format: <int>
@@ -472,10 +472,10 @@
for platform specific values (SB1, Loongson3 and
others).
- ccw_timeout_log [S390]
+ ccw_timeout_log [S390]
See Documentation/s390/CommonIO for details.
- cgroup_disable= [KNL] Disable a particular controller
+ cgroup_disable= [KNL] Disable a particular controller
Format: {name of the controller(s) to disable}
The effects of cgroup_disable=foo are:
- foo isn't auto-mounted if you mount all cgroups in
@@ -518,7 +518,7 @@
those clocks in any way. This parameter is useful for
debug and development, but should not be needed on a
platform with proper driver support. For more
- information, see Documentation/clk.txt.
+ information, see Documentation/driver-api/clk.rst.
clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
[Deprecated]
@@ -641,8 +641,8 @@
hvc<n> Use the hypervisor console device <n>. This is for
both Xen and PowerPC hypervisors.
- If the device connected to the port is not a TTY but a braille
- device, prepend "brl," before the device type, for instance
+ If the device connected to the port is not a TTY but a braille
+ device, prepend "brl," before the device type, for instance
console=brl,ttyS0
For now, only VisioBraille is supported.
@@ -662,7 +662,7 @@
consoleblank= [KNL] The console blank (screen saver) timeout in
seconds. A value of 0 disables the blank timer.
- Defaults to 0.
+ Defaults to 0.
coredump_filter=
[KNL] Change the default value for
@@ -730,7 +730,7 @@
or memory reserved is below 4G.
cryptomgr.notests
- [KNL] Disable crypto self-tests
+ [KNL] Disable crypto self-tests
cs89x0_dma= [HW,NET]
Format: <dma>
@@ -746,7 +746,7 @@
Format: <port#>,<type>
See also Documentation/input/devices/joystick-parport.rst
- ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
+ ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot
time. See
Documentation/admin-guide/dynamic-debug-howto.rst for
details. Deprecated, see dyndbg.
@@ -833,7 +833,7 @@
causing system reset or hang due to sending
INIT from AP to BSP.
- disable_ddw [PPC/PSERIES]
+ disable_ddw [PPC/PSERIES]
Disable Dynamic DMA Window support. Use this if
to workaround buggy firmware.
@@ -1188,7 +1188,7 @@
parameter will force ia64_sal_cache_flush to call
ia64_pal_cache_flush instead of SAL_CACHE_FLUSH.
- forcepae [X86-32]
+ forcepae [X86-32]
Forcefully enable Physical Address Extension (PAE).
Many Pentium M systems disable PAE but may have a
functionally usable PAE implementation.
@@ -1247,7 +1247,7 @@
gamma= [HW,DRM]
- gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
+ gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
Format: off | on
default: on
@@ -1341,23 +1341,32 @@
x86-64 are 2M (when the CPU supports "pse") and 1G
(when the CPU supports the "pdpe1gb" cpuinfo flag).
- hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
- terminal devices. Valid values: 0..8
- hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
- If specified, z/VM IUCV HVC accepts connections
- from listed z/VM user IDs only.
+ hung_task_panic=
+ [KNL] Should the hung task detector generate panics.
+ Format: <integer>
+ A nonzero value instructs the kernel to panic when a
+ hung task is detected. The default value is controlled
+ by the CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time
+ option. The value selected by this boot parameter can
+ be changed later by the kernel.hung_task_panic sysctl.
+
+ hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC)
+ terminal devices. Valid values: 0..8
+ hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
+ If specified, z/VM IUCV HVC accepts connections
+ from listed z/VM user IDs only.
keep_bootcon [KNL]
Do not unregister boot console at start. This is only
useful for debugging when something happens in the window
between unregistering the boot console and initializing
the real console.
- i2c_bus= [HW] Override the default board specific I2C bus speed
- or register an additional I2C bus that is not
- registered from board initialization code.
- Format:
- <bus_id>,<clkrate>
+ i2c_bus= [HW] Override the default board specific I2C bus speed
+ or register an additional I2C bus that is not
+ registered from board initialization code.
+ Format:
+ <bus_id>,<clkrate>
i8042.debug [HW] Toggle i8042 debug mode
i8042.unmask_kbd_data
@@ -1386,7 +1395,7 @@
Default: only on s2r transitions on x86; most other
architectures force reset to be always executed
i8042.unlock [HW] Unlock (ignore) the keylock
- i8042.kbdreset [HW] Reset device connected to KBD port
+ i8042.kbdreset [HW] Reset device connected to KBD port
i810= [HW,DRM]
@@ -1548,13 +1557,13 @@
programs exec'd, files mmap'd for exec, and all files
opened for read by uid=0.
- ima_template= [IMA]
+ ima_template= [IMA]
Select one of defined IMA measurements template formats.
Formats: { "ima" | "ima-ng" | "ima-sig" }
Default: "ima-ng"
ima_template_fmt=
- [IMA] Define a custom template format.
+ [IMA] Define a custom template format.
Format: { "field1|...|fieldN" }
ima.ahash_minsize= [IMA] Minimum file size for asynchronous hash usage
@@ -1597,7 +1606,7 @@
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
Format: <irq>
- int_pln_enable [x86] Enable power limit notification interrupt
+ int_pln_enable [x86] Enable power limit notification interrupt
integrity_audit=[IMA]
Format: { "0" | "1" }
@@ -1650,39 +1659,39 @@
0 disables intel_idle and fall back on acpi_idle.
1 to 9 specify maximum depth of C-state.
- intel_pstate= [X86]
- disable
- Do not enable intel_pstate as the default
- scaling driver for the supported processors
- passive
- Use intel_pstate as a scaling driver, but configure it
- to work with generic cpufreq governors (instead of
- enabling its internal governor). This mode cannot be
- used along with the hardware-managed P-states (HWP)
- feature.
- force
- Enable intel_pstate on systems that prohibit it by default
- in favor of acpi-cpufreq. Forcing the intel_pstate driver
- instead of acpi-cpufreq may disable platform features, such
- as thermal controls and power capping, that rely on ACPI
- P-States information being indicated to OSPM and therefore
- should be used with caution. This option does not work with
- processors that aren't supported by the intel_pstate driver
- or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
- no_hwp
- Do not enable hardware P state control (HWP)
- if available.
- hwp_only
- Only load intel_pstate on systems which support
- hardware P state control (HWP) if available.
- support_acpi_ppc
- Enforce ACPI _PPC performance limits. If the Fixed ACPI
- Description Table, specifies preferred power management
- profile as "Enterprise Server" or "Performance Server",
- then this feature is turned on by default.
- per_cpu_perf_limits
- Allow per-logical-CPU P-State performance control limits using
- cpufreq sysfs interface
+ intel_pstate= [X86]
+ disable
+ Do not enable intel_pstate as the default
+ scaling driver for the supported processors
+ passive
+ Use intel_pstate as a scaling driver, but configure it
+ to work with generic cpufreq governors (instead of
+ enabling its internal governor). This mode cannot be
+ used along with the hardware-managed P-states (HWP)
+ feature.
+ force
+ Enable intel_pstate on systems that prohibit it by default
+ in favor of acpi-cpufreq. Forcing the intel_pstate driver
+ instead of acpi-cpufreq may disable platform features, such
+ as thermal controls and power capping, that rely on ACPI
+ P-States information being indicated to OSPM and therefore
+ should be used with caution. This option does not work with
+ processors that aren't supported by the intel_pstate driver
+ or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
+ no_hwp
+ Do not enable hardware P state control (HWP)
+ if available.
+ hwp_only
+ Only load intel_pstate on systems which support
+ hardware P state control (HWP) if available.
+ support_acpi_ppc
+ Enforce ACPI _PPC performance limits. If the Fixed ACPI
+ Description Table, specifies preferred power management
+ profile as "Enterprise Server" or "Performance Server",
+ then this feature is turned on by default.
+ per_cpu_perf_limits
+ Allow per-logical-CPU P-State performance control limits using
+ cpufreq sysfs interface
intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
@@ -2026,7 +2035,7 @@
* [no]ncqtrim: Turn off queued DSM TRIM.
* nohrst, nosrst, norst: suppress hard, soft
- and both resets.
+ and both resets.
* rstonce: only attempt one reset during
hot-unplug link recovery
@@ -2214,7 +2223,7 @@
[KNL,SH] Allow user to override the default size for
per-device physically contiguous DMA buffers.
- memhp_default_state=online/offline
+ memhp_default_state=online/offline
[KNL] Set the initial state for the memory hotplug
onlining policy. If not specified, the default value is
set according to the
@@ -2764,7 +2773,7 @@
[X86,PV_OPS] Disable paravirtualized VMware scheduler
clock and use the default one.
- no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
+ no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting.
steal time is computed, but won't influence scheduler
behaviour
@@ -2825,7 +2834,7 @@
notsc [BUGS=X86-32] Disable Time Stamp Counter
nowatchdog [KNL] Disable both lockup detectors, i.e.
- soft-lockup and NMI watchdog (hard-lockup).
+ soft-lockup and NMI watchdog (hard-lockup).
nowb [ARM]
@@ -2845,7 +2854,7 @@
If the dependencies are under your control, you can
turn on cpu0_hotplug.
- nps_mtm_hs_ctr= [KNL,ARC]
+ 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.
@@ -2986,7 +2995,7 @@
pci=option[,option...] [PCI] various PCI subsystem options:
earlydump [X86] dump PCI config space before the kernel
- changes anything
+ changes anything
off [X86] don't probe for the PCI bus
bios [X86-32] force use of PCI BIOS, don't access
the hardware directly. Use this if your machine
@@ -3074,7 +3083,7 @@
is enabled by default. If you need to use this,
please report a bug.
nocrs [X86] Ignore PCI host bridge windows from ACPI.
- If you need to use this, please report a bug.
+ If you need to use this, please report a bug.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
so this option is a temporary workaround
@@ -3917,7 +3926,7 @@
cache (risks via metadata attacks are mostly
unchanged). Debug options disable merging on their
own.
- For more information see Documentation/vm/slub.txt.
+ For more information see Documentation/vm/slub.rst.
slab_max_order= [MM, SLAB]
Determines the maximum allowed order for slabs.
@@ -3931,7 +3940,7 @@
slub_debug can create guard zones around objects and
may poison objects when not in use. Also tracks the
last alloc / free. For more information see
- Documentation/vm/slub.txt.
+ Documentation/vm/slub.rst.
slub_memcg_sysfs= [MM, SLUB]
Determines whether to enable sysfs directories for
@@ -3945,7 +3954,7 @@
Determines the maximum allowed order for slabs.
A high setting may cause OOMs due to memory
fragmentation. For more information see
- Documentation/vm/slub.txt.
+ Documentation/vm/slub.rst.
slub_min_objects= [MM, SLUB]
The minimum number of objects per slab. SLUB will
@@ -3954,12 +3963,12 @@
the number of objects indicated. The higher the number
of objects the smaller the overhead of tracking slabs
and the less frequently locks need to be acquired.
- For more information see Documentation/vm/slub.txt.
+ For more information see Documentation/vm/slub.rst.
slub_min_order= [MM, SLUB]
Determines the minimum page order for slabs. Must be
lower than slub_max_order.
- For more information see Documentation/vm/slub.txt.
+ For more information see Documentation/vm/slub.rst.
slub_nomerge [MM, SLUB]
Same with slab_nomerge. This is supported for legacy.
@@ -4357,7 +4366,8 @@
Format: [always|madvise|never]
Can be used to control the default behavior of the system
with respect to transparent hugepages.
- See Documentation/vm/transhuge.txt for more details.
+ See Documentation/admin-guide/mm/transhuge.rst
+ for more details.
tsc= Disable clocksource stability checks for TSC.
Format: <string>
@@ -4435,7 +4445,7 @@
usbcore.initial_descriptor_timeout=
[USB] Specifies timeout for the initial 64-byte
- USB_REQ_GET_DESCRIPTOR request in milliseconds
+ USB_REQ_GET_DESCRIPTOR request in milliseconds
(default 5000 = 5.0 seconds).
usbcore.nousb [USB] Disable the USB subsystem