This mode requires kvm-amd.avic=1.
(Default when IOMMU HW support is present.)
+ amd_pstate= [X86]
+ disable
+ Do not enable amd_pstate as the default
+ scaling driver for the supported processors
+ passive
+ Use amd_pstate with passive mode as a scaling driver.
+ In this mode autonomous selection is disabled.
+ Driver requests a desired performance level and platform
+ tries to match the same performance level if it is
+ satisfied by guaranteed performance level.
+ active
+ Use amd_pstate_epp driver instance as the scaling driver,
+ driver provides a hint to the hardware if software wants
+ to bias toward performance (0x0) or energy efficiency (0xff)
+ to the CPPC firmware. then CPPC power algorithm will
+ calculate the runtime workload and adjust the realtime cores
+ frequency.
+ guided
+ Activate guided autonomous mode. Driver requests minimum and
+ maximum performance level and the platform autonomously
+ selects a performance level in this range and appropriate
+ to the current workload.
+
amijoy.map= [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT
Format: <a>,<b>
debug_objects [KNL] Enable object debugging
- no_debug_objects
- [KNL] Disable object debugging
-
debug_guardpage_minorder=
[KNL] When CONFIG_DEBUG_PAGEALLOC is set, this
parameter allows control of the order of pages that will
dependencies. This only applies for fw_devlink=on|rpm.
Format: <bool>
+ fw_devlink.sync_state =
+ [KNL] When all devices that could probe have finished
+ probing, this parameter controls what to do with
+ devices that haven't yet received their sync_state()
+ calls.
+ Format: { strict | timeout }
+ strict -- Default. Continue waiting on consumers to
+ probe successfully.
+ timeout -- Give up waiting on consumers and call
+ sync_state() on any devices that haven't yet
+ received their sync_state() calls after
+ deferred_probe_timeout has expired or by
+ late_initcall() if !CONFIG_MODULES.
+
gamecon.map[2|3]=
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
support via parallel port (up to 5 devices per port)
mce [X86-32] Machine Check Exception
- mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst
+ mce=option [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
md= [HW] RAID subsystems devices and level
See Documentation/admin-guide/md.rst.
deep - Suspend-To-RAM or equivalent (if supported)
See Documentation/admin-guide/pm/sleep-states.rst.
- meye.*= [HW] Set MotionEye Camera parameters
- See Documentation/admin-guide/media/meye.rst.
-
mfgpt_irq= [IA-32] Specify the IRQ to use for the
Multi-Function General Purpose Timers on AMD Geode
platforms.
specified, <module>.async_probe takes precedence for
the specific module.
+ module.enable_dups_trace
+ [KNL] When CONFIG_MODULE_DEBUG_AUTOLOAD_DUPS is set,
+ this means that duplicate request_module() calls will
+ trigger a WARN_ON() instead of a pr_warn(). Note that
+ if MODULE_DEBUG_AUTOLOAD_DUPS_TRACE is set, WARN_ON()s
+ will always be issued and this option does nothing.
module.sig_enforce
[KNL] When CONFIG_MODULE_SIG is set, this means that
modules without (valid) signatures will fail to load.
1 to enable accounting
Default value is 0.
- nfsaddrs= [NFS] Deprecated. Use ip= instead.
- See Documentation/admin-guide/nfs/nfsroot.rst.
-
- nfsroot= [NFS] nfs root filesystem for disk-less boxes.
- See Documentation/admin-guide/nfs/nfsroot.rst.
+ nfs.cache_getent=
+ [NFS] sets the pathname to the program which is used
+ to update the NFS client cache entries.
- nfsrootdebug [NFS] enable nfsroot debugging messages.
- See Documentation/admin-guide/nfs/nfsroot.rst.
+ nfs.cache_getent_timeout=
+ [NFS] sets the timeout after which an attempt to
+ update a cache entry is deemed to have failed.
nfs.callback_nr_threads=
[NFSv4] set the total number of threads that the
[NFS] set the TCP port on which the NFSv4 callback
channel should listen.
- nfs.cache_getent=
- [NFS] sets the pathname to the program which is used
- to update the NFS client cache entries.
-
- nfs.cache_getent_timeout=
- [NFS] sets the timeout after which an attempt to
- update a cache entry is deemed to have failed.
-
- nfs.idmap_cache_timeout=
- [NFS] set the maximum lifetime for idmapper cache
- entries.
-
nfs.enable_ino64=
[NFS] enable 64-bit inode numbers.
If zero, the NFS client will fake up a 32-bit inode
of returning the full 64-bit number.
The default is to return 64-bit inode numbers.
+ nfs.idmap_cache_timeout=
+ [NFS] set the maximum lifetime for idmapper cache
+ entries.
+
nfs.max_session_cb_slots=
[NFSv4.1] Sets the maximum number of session
slots the client will assign to the callback
will be autodetected by the client, and it will fall
back to using the idmapper.
To turn off this behaviour, set the value to '0'.
+
nfs.nfs4_unique_id=
[NFS4] Specify an additional fixed unique ident-
ification string that NFSv4 clients can insert into
their nfs_client_id4 string. This is typically a
UUID that is generated at system install time.
- nfs.send_implementation_id =
- [NFSv4.1] Send client implementation identification
- information in exchange_id requests.
- If zero, no implementation identification information
- will be sent.
- The default is to send the implementation identification
- information.
-
- nfs.recover_lost_locks =
+ nfs.recover_lost_locks=
[NFSv4] Attempt to recover locks that were lost due
to a lease timeout on the server. Please note that
doing this risks data corruption, since there are
The default parameter value of '0' causes the kernel
not to attempt recovery of lost locks.
- nfs4.layoutstats_timer =
+ nfs.send_implementation_id=
+ [NFSv4.1] Send client implementation identification
+ information in exchange_id requests.
+ If zero, no implementation identification information
+ will be sent.
+ The default is to send the implementation identification
+ information.
+
+ nfs4.layoutstats_timer=
[NFSv4.2] Change the rate at which the kernel sends
layoutstats to the pNFS metadata server.
driver. A non-zero value sets the minimum interval
in seconds between layoutstats transmissions.
- nfsd.inter_copy_offload_enable =
+ nfsd.inter_copy_offload_enable=
[NFSv4.2] When set to 1, the server will support
server-to-server copies for which this server is
the destination of the copy.
- nfsd.nfsd4_ssc_umount_timeout =
+ nfsd.nfs4_disable_idmapping=
+ [NFSv4] When set to the default of '1', the NFSv4
+ server will return only numeric uids and gids to
+ clients using auth_sys, and will accept numeric uids
+ and gids from such clients. This is intended to ease
+ migration from NFSv2/v3.
+
+ nfsd.nfsd4_ssc_umount_timeout=
[NFSv4.2] When used as the destination of a
server-to-server copy, knfsd temporarily mounts
the source server. It caches the mount in case
used for the number of milliseconds specified by
this parameter.
- nfsd.nfs4_disable_idmapping=
- [NFSv4] When set to the default of '1', the NFSv4
- server will return only numeric uids and gids to
- clients using auth_sys, and will accept numeric uids
- and gids from such clients. This is intended to ease
- migration from NFSv2/v3.
+ nfsaddrs= [NFS] Deprecated. Use ip= instead.
+ See Documentation/admin-guide/nfs/nfsroot.rst.
+ nfsroot= [NFS] nfs root filesystem for disk-less boxes.
+ See Documentation/admin-guide/nfs/nfsroot.rst.
+
+ nfsrootdebug [NFS] enable nfsroot debugging messages.
+ See Documentation/admin-guide/nfs/nfsroot.rst.
nmi_backtrace.backtrace_idle [KNL]
Dump stacks even of idle CPUs in response to an
no5lvl [X86-64] Disable 5-level paging mode. Forces
kernel to use 4-level paging instead.
- nofsgsbase [X86] Disables FSGSBASE instructions.
+ noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
+ caches in the slab allocator. Saves per-node memory,
+ but will impact performance.
+
+ 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.
+
+ noautogroup Disable scheduler automatic task group creation.
+
+ nocache [ARM]
no_console_suspend
[HW] Never suspend the console
/sys/module/printk/parameters/console_suspend) to
turn on/off it dynamically.
- novmcoredd [KNL,KDUMP]
- Disable device dump. Device dump allows drivers to
- append dump data to vmcore so you can collect driver
- specified debug info. Drivers can append the data
- without any limit and this data is stored in memory,
- so this may cause significant memory stress. Disabling
- device dump can help save memory but the driver debug
- data will be no longer available. This parameter
- is only available when CONFIG_PROC_VMCORE_DEVICE_DUMP
- is set.
-
- noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
- caches in the slab allocator. Saves per-node memory,
- but will impact performance.
-
- 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.
-
- noautogroup Disable scheduler automatic task group creation.
-
- nocache [ARM]
+ no_debug_objects
+ [KNL] Disable object debugging
nodsp [SH] Disable hardware DSP at boot time.
noexec [IA-64]
- nosmap [PPC]
- Disable SMAP (Supervisor Mode Access Prevention)
- even if it is supported by processor.
-
- nosmep [PPC64s]
- Disable SMEP (Supervisor Mode Execution Prevention)
- even if it is supported by processor.
-
noexec32 [X86-64]
This affects only 32-bit executables.
noexec32=on: enable non-executable mappings (default)
noexec32=off: disable non-executable mappings
read implies executable mappings
+ no_file_caps Tells the kernel not to honor file capabilities. The
+ only way then for a file to be executed with privilege
+ is to be setuid root or executed by root.
+
nofpu [MIPS,SH] Disable hardware FPU at boot time.
+ nofsgsbase [X86] Disables FSGSBASE instructions.
+
nofxsr [BUGS=X86-32] Disables x86 floating point extended
register save and restore. The kernel will only save
legacy floating-point registers on task switch.
- nohugeiomap [KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
-
- nohugevmalloc [KNL,X86,PPC,ARM64] Disable kernel huge vmalloc mappings.
-
- nosmt [KNL,S390] Disable symmetric multithreading (SMT).
- Equivalent to smt=1.
-
- [KNL,X86] Disable symmetric multithreading (SMT).
- nosmt=force: Force disable SMT, cannot be undone
- via the sysfs control file.
-
- nospectre_v1 [X86,PPC] Disable mitigations for Spectre Variant 1
- (bounds check bypass). With this option data leaks are
- possible in the system.
-
- nospectre_v2 [X86,PPC_E500,ARM64] Disable all mitigations for
- the Spectre variant 2 (indirect branch prediction)
- vulnerability. System may allow data leaks with this
- option.
-
- nospectre_bhb [ARM64] Disable all mitigations for Spectre-BHB (branch
- history injection) vulnerability. System may allow data leaks
- with this option.
-
- nospec_store_bypass_disable
- [HW] Disable all mitigations for the Speculative Store Bypass vulnerability
-
- no_uaccess_flush
- [PPC] Don't flush the L1-D cache after accessing user data.
-
- noxsave [BUGS=X86] Disables x86 extended register state save
- and restore using xsave. The kernel will fallback to
- enabling legacy floating-point and sse state.
-
- noxsaveopt [X86] Disables xsaveopt used in saving x86 extended
- register states. The kernel will fall back to use
- xsave to save the states. By using this parameter,
- performance of saving the states is degraded because
- xsave doesn't support modified optimization while
- xsaveopt supports it on xsaveopt enabled systems.
-
- noxsaves [X86] Disables xsaves and xrstors used in saving and
- restoring x86 extended register state in compacted
- form of xsave area. The kernel will fall back to use
- xsaveopt and xrstor to save and restore the states
- in standard form of xsave area. By using this
- parameter, xsave area per process might occupy more
- memory on xsaves enabled systems.
-
- nohlt [ARM,ARM64,MICROBLAZE,SH] Forces the kernel to busy wait
- in do_idle() and not use the arch_cpu_idle()
- implementation; requires CONFIG_GENERIC_IDLE_POLL_SETUP
- to be effective. This is useful on platforms where the
- sleep(SH) or wfi(ARM,ARM64) instructions do not work
- correctly or when doing power measurements to evaluate
- the impact of the sleep instructions. This is also
- useful when using JTAG debugger.
-
- no_file_caps Tells the kernel not to honor file capabilities. The
- only way then for a file to be executed with privilege
- is to be setuid root or executed by root.
-
nohalt [IA-64] Tells the kernel not to use the power saving
function PAL_HALT_LIGHT when idle. This increases
power-consumption. On the positive side, it reduces
nohibernate [HIBERNATION] Disable hibernation and resume.
+ nohlt [ARM,ARM64,MICROBLAZE,SH] Forces the kernel to busy wait
+ in do_idle() and not use the arch_cpu_idle()
+ implementation; requires CONFIG_GENERIC_IDLE_POLL_SETUP
+ to be effective. This is useful on platforms where the
+ sleep(SH) or wfi(ARM,ARM64) instructions do not work
+ correctly or when doing power measurements to evaluate
+ the impact of the sleep instructions. This is also
+ useful when using JTAG debugger.
+
+ nohugeiomap [KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
+
+ nohugevmalloc [KNL,X86,PPC,ARM64] Disable kernel huge vmalloc mappings.
+
nohz= [KNL] Boottime enable/disable dynamic ticks
Valid arguments: on, off
Default: on
Note that this argument takes precedence over
the CONFIG_RCU_NOCB_CPU_DEFAULT_ALL option.
- noiotrap [SH] Disables trapped I/O port accesses.
-
- noirqdebug [X86-32] Disables the code which attempts to detect and
- disable unhandled interrupt sources.
-
- no_timer_check [X86,APIC] Disables the code which tests for
- broken timer IRQ sources.
-
- noisapnp [ISAPNP] Disables ISA PnP code.
-
noinitrd [RAM] Tells the kernel not to load any configured
initial RAM disk.
noinvpcid [X86] Disable the INVPCID cpu feature.
+ noiotrap [SH] Disables trapped I/O port accesses.
+
+ noirqdebug [X86-32] Disables the code which attempts to detect and
+ disable unhandled interrupt sources.
+
+ noisapnp [ISAPNP] Disables ISA PnP code.
+
nojitter [IA-64] Disables jitter checking for ITC timers.
nokaslr [KNL]
kernel and module base offset ASLR (Address Space
Layout Randomization).
- no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
-
no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page
fault handling.
- no-vmw-sched-clock
- [X86,PV_OPS] Disable paravirtualized VMware scheduler
- clock and use the default one.
-
- no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES] Disable paravirtualized
- steal time accounting. steal time is computed, but
- won't influence scheduler behaviour
+ no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
nolapic [X86-32,APIC] Do not enable or use the local APIC.
nomfgpt [X86-32] Disable Multi-Function General Purpose
Timer usage (for AMD Geode machines).
- nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to
- shutdown the other cpus. Instead use the REBOOT_VECTOR
- irq.
-
nomodeset Disable kernel modesetting. Most systems' firmware
sets up a display mode and provides framebuffer memory
for output. With nomodeset, DRM and fbdev drivers will
nomodule Disable module load
+ nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to
+ shutdown the other cpus. Instead use the REBOOT_VECTOR
+ irq.
+
nopat [X86] Disable PAT (page attribute table extension of
pagetables) support.
nopku [X86] Disable Memory Protection Keys CPU feature found
in some Intel CPUs.
+ nopti [X86-64]
+ Equivalent to pti=off
+
nopv= [X86,XEN,KVM,HYPER_V,VMWARE]
Disables the PV optimizations forcing the guest to run
as generic guest with no PV drivers. Currently support
noresume [SWSUSP] Disables resume and restores original swap
space.
+ nosbagart [IA-64]
+
no-scroll [VGA] Disables scrollback.
This is required for the Braillex ib80-piezo Braille
reader made by F.H. Papenmeier (Germany).
- nosbagart [IA-64]
-
nosgx [X86-64,SGX] Disables Intel SGX kernel support.
+ nosmap [PPC]
+ Disable SMAP (Supervisor Mode Access Prevention)
+ even if it is supported by processor.
+
+ nosmep [PPC64s]
+ Disable SMEP (Supervisor Mode Execution Prevention)
+ even if it is supported by processor.
+
nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
and disable the IO APIC. legacy for "maxcpus=0".
+ nosmt [KNL,S390] Disable symmetric multithreading (SMT).
+ Equivalent to smt=1.
+
+ [KNL,X86] Disable symmetric multithreading (SMT).
+ nosmt=force: Force disable SMT, cannot be undone
+ via the sysfs control file.
+
nosoftlockup [KNL] Disable the soft-lockup detector.
+ nospec_store_bypass_disable
+ [HW] Disable all mitigations for the Speculative Store Bypass vulnerability
+
+ nospectre_bhb [ARM64] Disable all mitigations for Spectre-BHB (branch
+ history injection) vulnerability. System may allow data leaks
+ with this option.
+
+ nospectre_v1 [X86,PPC] Disable mitigations for Spectre Variant 1
+ (bounds check bypass). With this option data leaks are
+ possible in the system.
+
+ nospectre_v2 [X86,PPC_E500,ARM64] Disable all mitigations for
+ the Spectre variant 2 (indirect branch prediction)
+ vulnerability. System may allow data leaks with this
+ option.
+
+ no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES] Disable paravirtualized
+ steal time accounting. steal time is computed, but
+ won't influence scheduler behaviour
+
nosync [HW,M68K] Disables sync negotiation for all devices.
+ no_timer_check [X86,APIC] Disables the code which tests for
+ broken timer IRQ sources.
+
+ no_uaccess_flush
+ [PPC] Don't flush the L1-D cache after accessing user data.
+
+ novmcoredd [KNL,KDUMP]
+ Disable device dump. Device dump allows drivers to
+ append dump data to vmcore so you can collect driver
+ specified debug info. Drivers can append the data
+ without any limit and this data is stored in memory,
+ so this may cause significant memory stress. Disabling
+ device dump can help save memory but the driver debug
+ data will be no longer available. This parameter
+ is only available when CONFIG_PROC_VMCORE_DEVICE_DUMP
+ is set.
+
+ no-vmw-sched-clock
+ [X86,PV_OPS] Disable paravirtualized VMware scheduler
+ clock and use the default one.
+
nowatchdog [KNL] Disable both lockup detectors, i.e.
soft-lockup and NMI watchdog (hard-lockup).
LEGACY_XAPIC_DISABLED bit set in the
IA32_XAPIC_DISABLE_STATUS MSR.
+ noxsave [BUGS=X86] Disables x86 extended register state save
+ and restore using xsave. The kernel will fallback to
+ enabling legacy floating-point and sse state.
+
+ noxsaveopt [X86] Disables xsaveopt used in saving x86 extended
+ register states. The kernel will fall back to use
+ xsave to save the states. By using this parameter,
+ performance of saving the states is degraded because
+ xsave doesn't support modified optimization while
+ xsaveopt supports it on xsaveopt enabled systems.
+
+ noxsaves [X86] Disables xsaves and xrstors used in saving and
+ restoring x86 extended register state in compacted
+ form of xsave area. The kernel will fall back to use
+ xsaveopt and xrstor to save and restore the states
+ in standard form of xsave area. By using this
+ parameter, xsave area per process might occupy more
+ memory on xsaves enabled systems.
+
nps_mtm_hs_ctr= [KNL,ARC]
This parameter sets the maximum duration, in
cycles, each HW thread of the CTOP can run
and performance comparison.
pirq= [SMP,APIC] Manual mp-table setup
- See Documentation/x86/i386/IO-APIC.rst.
+ See Documentation/arch/x86/i386/IO-APIC.rst.
plip= [PPT,NET] Parallel port network link
Format: { parport<nr> | timid | 0 }
Not specifying this option is equivalent to pti=auto.
- nopti [X86-64]
- Equivalent to pti=off
-
pty.legacy_count=
[KNL] Number of legacy pty's. Overwrites compiled-in
default number.
serialnumber [BUGS=X86-32]
- sev=option[,option...] [X86-64] See Documentation/x86/x86_64/boot-options.rst
+ sev=option[,option...] [X86-64] See Documentation/arch/x86/x86_64/boot-options.rst
shapers= [NET]
Maximal number of shapers.
later by a loaded module cannot be set this way.
Example: sysctl.vm.swappiness=40
- sysfs.deprecated=0|1 [KNL]
- Enable/disable old style sysfs layout for old udev
- on older distributions. When this option is enabled
- very new udev will not work anymore. When this option
- is disabled (or CONFIG_SYSFS_DEPRECATED not compiled)
- in older udev will not work anymore.
- Default depends on CONFIG_SYSFS_DEPRECATED_V2 set in
- the kernel configuration.
-
sysrq_always_enabled
[KNL]
Ignore sysrq setting - this boot parameter will
Can be used multiple times for multiple devices.
vga= [BOOT,X86-32] Select a particular video mode
- See Documentation/x86/boot.rst and
+ See Documentation/arch/x86/boot.rst and
Documentation/admin-guide/svga.rst.
Use vga=ask for menu.
This is actually a boot loader parameter; the value is
When enabled, memory and cache locality will be
impacted.
+ writecombine= [LOONGARCH] Control the MAT (Memory Access Type) of
+ ioremap_wc().
+
+ on - Enable writecombine, use WUC for ioremap_wc()
+ off - Disable writecombine, use SUC for ioremap_wc()
+
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
default x2apic cluster mode on platforms
supporting x2apic.
xmon commands.
off xmon is disabled.
- amd_pstate= [X86]
- disable
- Do not enable amd_pstate as the default
- scaling driver for the supported processors
- passive
- Use amd_pstate as a scaling driver, driver requests a
- desired performance on this abstract scale and the power
- management firmware translates the requests into actual
- hardware states (core frequency, data fabric and memory
- clocks etc.)
- active
- Use amd_pstate_epp driver instance as the scaling driver,
- driver provides a hint to the hardware if software wants
- to bias toward performance (0x0) or energy efficiency (0xff)
- to the CPPC firmware. then CPPC power algorithm will
- calculate the runtime workload and adjust the realtime cores
- frequency.
projects / linux-block.git / blobdiff