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Documentation/kernel-parameters.txt
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Kernel Parameters ~~~~~~~~~~~~~~~~~ |
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The following is a consolidated list of the kernel parameters as implemented (mostly) by the __setup() macro and sorted into English Dictionary order (defined as ignoring all punctuation and sorting digits before letters in a case insensitive manner), and with descriptions where known. Module parameters for loadable modules are specified only as the parameter name with optional '=' and value as appropriate, such as: modprobe usbcore blinkenlights=1 Module parameters for modules that are built into the kernel image are specified on the kernel command line with the module name plus '.' plus parameter name, with '=' and value if appropriate, such as: usbcore.blinkenlights=1 |
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Hyphens (dashes) and underscores are equivalent in parameter names, so log_buf_len=1M print-fatal-signals=1 can also be entered as log-buf-len=1M print_fatal_signals=1 |
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This document may not be entirely up to date and comprehensive. The command "modinfo -p ${modulename}" shows a current list of all parameters of a loadable module. Loadable modules, after being loaded into the running kernel, also reveal their parameters in /sys/module/${modulename}/parameters/. Some of these parameters may be changed at runtime by the command "echo -n ${value} > /sys/module/${modulename}/parameters/${parm}". |
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The parameters listed below are only valid if certain kernel build options were enabled and if respective hardware is present. The text in square brackets at the beginning of each description states the restrictions within which a parameter is applicable: |
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ACPI ACPI support is enabled. |
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AGP AGP (Accelerated Graphics Port) is enabled. |
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ALSA ALSA sound support is enabled. APIC APIC support is enabled. APM Advanced Power Management support is enabled. |
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ARM ARM architecture is enabled. |
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AVR32 AVR32 architecture is enabled. |
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AX25 Appropriate AX.25 support is enabled. |
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BLACKFIN Blackfin architecture is enabled. |
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CLK Common clock infrastructure is enabled. |
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CMA Contiguous Memory Area support is enabled. |
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DRM Direct Rendering Management support is enabled. DYNAMIC_DEBUG Build in debug messages and enable them at runtime |
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EDD BIOS Enhanced Disk Drive Services (EDD) is enabled EFI EFI Partitioning (GPT) is enabled EIDE EIDE/ATAPI support is enabled. |
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EVM Extended Verification Module |
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FB The frame buffer device is enabled. |
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FTRACE Function tracing enabled. |
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GCOV GCOV profiling is enabled. |
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HW Appropriate hardware is enabled. |
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IA-64 IA-64 architecture is enabled. |
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IMA Integrity measurement architecture is enabled. |
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IOSCHED More than one I/O scheduler is enabled. |
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IP_PNP IP DHCP, BOOTP, or RARP is enabled. |
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IPV6 IPv6 support is enabled. |
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ISAPNP ISA PnP code is enabled. ISDN Appropriate ISDN support is enabled. JOY Appropriate joystick support is enabled. |
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KGDB Kernel debugger support is enabled. |
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KVM Kernel Virtual Machine support is enabled. |
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LIBATA Libata driver is enabled |
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LP Printer support is enabled. LOOP Loopback device support is enabled. M68k M68k architecture is enabled. These options have more detailed description inside of Documentation/m68k/kernel-options.txt. |
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MDA MDA console support is enabled. |
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MIPS MIPS architecture is enabled. |
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MOUSE Appropriate mouse support is enabled. |
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MSI Message Signaled Interrupts (PCI). |
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MTD MTD (Memory Technology Device) support is enabled. |
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NET Appropriate network support is enabled. NUMA NUMA support is enabled. NFS Appropriate NFS support is enabled. OSS OSS sound support is enabled. |
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PV_OPS A paravirtualized kernel is enabled. PARIDE The ParIDE (parallel port IDE) subsystem is enabled. |
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PARISC The PA-RISC architecture is enabled. PCI PCI bus support is enabled. |
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PCIE PCI Express support is enabled. |
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PCMCIA The PCMCIA subsystem is enabled. PNP Plug & Play support is enabled. PPC PowerPC architecture is enabled. PPT Parallel port support is enabled. PS2 Appropriate PS/2 support is enabled. RAM RAM disk support is enabled. S390 S390 architecture is enabled. SCSI Appropriate SCSI support is enabled. |
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A lot of drivers have their options described inside the Documentation/scsi/ sub-directory. |
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SECURITY Different security models are enabled. |
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SELINUX SELinux support is enabled. |
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APPARMOR AppArmor support is enabled. |
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SERIAL Serial support is enabled. |
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SH SuperH architecture is enabled. |
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SMP The kernel is an SMP kernel. SPARC Sparc architecture is enabled. |
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SWSUSP Software suspend (hibernation) is enabled. SUSPEND System suspend states are enabled. |
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TPM TPM drivers are enabled. |
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TS Appropriate touchscreen support is enabled. |
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UMS USB Mass Storage support is enabled. |
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USB USB support is enabled. USBHID USB Human Interface Device support is enabled. V4L Video For Linux support is enabled. |
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VMMIO Driver for memory mapped virtio devices is enabled. |
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VGA The VGA console has been enabled. VT Virtual terminal support is enabled. WDT Watchdog support is enabled. XT IBM PC/XT MFM hard disk support is enabled. |
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X86-32 X86-32, aka i386 architecture is enabled. |
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X86-64 X86-64 architecture is enabled. More X86-64 boot options can be found in |
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Documentation/x86/x86_64/boot-options.txt . |
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X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64) |
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XEN Xen support is enabled |
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In addition, the following text indicates that the option: BUGS= Relates to possible processor bugs on the said processor. KNL Is a kernel start-up parameter. BOOT Is a boot loader parameter. Parameters denoted with BOOT are actually interpreted by the boot loader, and have no meaning to the kernel directly. Do not modify the syntax of boot loader parameters without extreme |
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need or coordination with <Documentation/x86/boot.txt>. |
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There are also arch-specific kernel-parameters not documented here. |
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See for example <Documentation/x86/x86_64/boot-options.txt>. |
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Note that ALL kernel parameters listed below are CASE SENSITIVE, and that a trailing = on the name of any parameter states that that parameter will be entered as an environment variable, whereas its absence indicates that it will appear as a kernel argument readable via /proc/cmdline by programs running once the system is up. |
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The number of kernel parameters is not limited, but the length of the complete command line (parameters including spaces etc.) is limited to a fixed number of characters. This limit depends on the architecture and is between 256 and 4096 characters. It is defined in the file ./include/asm/setup.h as COMMAND_LINE_SIZE. |
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Finally, the [KMG] suffix is commonly described after a number of kernel parameter values. These 'K', 'M', and 'G' letters represent the _binary_ multipliers 'Kilo', 'Mega', and 'Giga', equalling 2^10, 2^20, and 2^30 bytes respectively. Such letter suffixes can also be entirely omitted. |
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acpi= [HW,ACPI,X86] |
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Advanced Configuration and Power Interface |
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Format: { force | off | strict | noirq | rsdt } |
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force -- enable ACPI if default was off off -- disable ACPI if default was on noirq -- do not use ACPI for IRQ routing |
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strict -- Be less tolerant of platforms that are not |
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strictly ACPI specification compliant. |
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rsdt -- prefer RSDT over (default) XSDT |
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copy_dsdt -- copy DSDT to memory |
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See also Documentation/power/runtime_pm.txt, pci=noacpi |
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acpi_rsdp= [ACPI,EFI,KEXEC] Pass the RSDP address to the kernel, mostly used on machines running EFI runtime service to boot the second kernel for kdump. |
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acpi_apic_instance= [ACPI, IOAPIC] Format: <int> 2: use 2nd APIC table, if available 1,0: use 1st APIC table |
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default: 0 |
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acpi_backlight= [HW,ACPI] acpi_backlight=vendor acpi_backlight=video If set to vendor, prefer vendor specific driver (e.g. thinkpad_acpi, sony_acpi, etc.) instead of the ACPI video.ko driver. |
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acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] acpi.debug_level= [HW,ACPI,ACPI_DEBUG] |
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Format: <int> |
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CONFIG_ACPI_DEBUG must be enabled to produce any ACPI debug output. Bits in debug_layer correspond to a _COMPONENT in an ACPI source file, e.g., #define _COMPONENT ACPI_PCI_COMPONENT Bits in debug_level correspond to a level in ACPI_DEBUG_PRINT statements, e.g., ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... |
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The debug_level mask defaults to "info". See Documentation/acpi/debug.txt for more information about debug layers and levels. |
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Enable processor driver info messages: acpi.debug_layer=0x20000000 Enable PCI/PCI interrupt routing info messages: acpi.debug_layer=0x400000 |
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Enable AML "Debug" output, i.e., stores to the Debug object while interpreting AML: acpi.debug_layer=0xffffffff acpi.debug_level=0x2 |
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Enable all messages related to ACPI hardware: acpi.debug_layer=0x2 acpi.debug_level=0xffffffff Some values produce so much output that the system is unusable. The "log_buf_len" parameter may be useful if you need to capture more output. |
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acpi_irq_balance [HW,ACPI] ACPI will balance active IRQs default in APIC mode acpi_irq_nobalance [HW,ACPI] ACPI will not move active IRQs (default) default in PIC mode acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA Format: <irq>,<irq>... acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for use by PCI Format: <irq>,<irq>... acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS Format: To spoof as Windows 98: ="Microsoft Windows" acpi_osi= [HW,ACPI] Modify list of supported OS interface strings |
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acpi_osi="string1" # add string1 acpi_osi="!string2" # remove string2 |
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acpi_osi=!* # remove all strings |
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acpi_osi=! # disable all built-in OS vendor strings |
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acpi_osi= # disable all strings |
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'acpi_osi=!' can be used in combination with single or multiple 'acpi_osi="string1"' to support specific OS vendor string(s). Note that such command can only affect the default state of the OS vendor strings, thus it cannot affect the default state of the feature group strings and the current state of the OS vendor strings, specifying it multiple times through kernel command line |
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is meaningless. This command is useful when one do not care about the state of the feature group strings which should be controlled by the OSPM. |
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Examples: 1. 'acpi_osi=! acpi_osi="Windows 2000"' is equivalent to 'acpi_osi="Windows 2000" acpi_osi=!', they all can make '_OSI("Windows 2000")' TRUE. 'acpi_osi=' cannot be used in combination with other 'acpi_osi=' command lines, the _OSI method will not exist in the ACPI namespace. NOTE that such command can only affect the _OSI support state, thus specifying it multiple times through kernel command line is also meaningless. Examples: 1. 'acpi_osi=' can make 'CondRefOf(_OSI, Local1)' FALSE. |
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'acpi_osi=!*' can be used in combination with single or multiple 'acpi_osi="string1"' to support specific string(s). Note that such command can affect the current state of both the OS vendor strings and the feature group strings, thus specifying it multiple times through kernel command line is meaningful. But it may still not able to affect the final state of a string if there are quirks related to this string. This command is useful when one want to control the state of the feature group strings to debug BIOS issues related to the OSPM features. Examples: 1. 'acpi_osi="Module Device" acpi_osi=!*' can make '_OSI("Module Device")' FALSE. 2. 'acpi_osi=!* acpi_osi="Module Device"' can make '_OSI("Module Device")' TRUE. 3. 'acpi_osi=! acpi_osi=!* acpi_osi="Windows 2000"' is equivalent to 'acpi_osi=!* acpi_osi=! acpi_osi="Windows 2000"' and 'acpi_osi=!* acpi_osi="Windows 2000" acpi_osi=!', they all will make '_OSI("Windows 2000")' TRUE. |
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acpi_pm_good [X86] |
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Override the pmtimer bug detection: force the kernel to assume that this machine's pmtimer latches its value and always returns good values. |
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acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode Format: { level | edge | high | low } acpi_serialize [HW,ACPI] force serialization of AML methods acpi_skip_timer_override [HW,ACPI] Recognize and ignore IRQ0/pin2 Interrupt Override. For broken nForce2 BIOS resulting in XT-PIC timer. acpi_sleep= [HW,ACPI] Sleep options Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, |
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old_ordering, nonvs, sci_force_enable } |
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See Documentation/power/video.txt for information on s3_bios and s3_mode. s3_beep is for debugging; it makes the PC's speaker beep as soon as the kernel's real-mode entry point is called. s4_nohwsig prevents ACPI hardware signature from being used during resume from hibernation. old_ordering causes the ACPI 1.0 ordering of the _PTS control method, with respect to putting devices into low power states, to be enforced (the ACPI 2.0 ordering of _PTS is used by default). |
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nonvs prevents the kernel from saving/restoring the ACPI NVS memory during suspend/hibernation and resume. |
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sci_force_enable causes the kernel to set SCI_EN directly on resume from S1/S3 (which is against the ACPI spec, but some broken systems don't work without it). |
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acpi_use_timer_override [HW,ACPI] Use timer override. For some broken Nvidia NF5 boards that require a timer override, but don't have HPET |
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acpi_enforce_resources= [ACPI] { strict | lax | no } Check for resource conflicts between native drivers and ACPI OperationRegions (SystemIO and SystemMemory only). IO ports and memory declared in ACPI might be used by the ACPI subsystem in arbitrary AML code and can interfere with legacy drivers. strict (default): access to resources claimed by ACPI is denied; legacy drivers trying to access reserved resources will fail to bind to device using them. lax: access to resources claimed by ACPI is allowed; legacy drivers trying to access reserved resources will bind successfully but a warning message is logged. no: ACPI OperationRegions are not marked as reserved, no further checks are performed. |
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add_efi_memmap [EFI; X86] Include EFI memory map in kernel's map of available physical RAM. |
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agp= [AGP] { off | try_unsupported } off: disable AGP support try_unsupported: try to drive unsupported chipsets (may crash computer or cause data corruption) |
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ALSA [HW,ALSA] See Documentation/sound/alsa/alsa-parameters.txt |
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alignment= [KNL,ARM] Allow the default userspace alignment fault handler behaviour to be specified. Bit 0 enables warnings, bit 1 enables fixups, and bit 2 sends a segfault. |
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align_va_addr= [X86-64] Align virtual addresses by clearing slice [14:12] when allocating a VMA at process creation time. This option gives you up to 3% performance improvement on AMD F15h machines (where it is enabled by default) for a CPU-intensive style benchmark, and it can vary highly in a microbenchmark depending on workload and compiler. |
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32: only for 32-bit processes 64: only for 64-bit processes |
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on: enable for both 32- and 64-bit processes off: disable for both 32- and 64-bit processes |
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alloc_snapshot [FTRACE] Allocate the ftrace snapshot buffer on boot up when the main buffer is allocated. This is handy if debugging and you need to use tracing_snapshot() on boot up, and do not want to use tracing_snapshot_alloc() as it needs to be done where GFP_KERNEL allocations are allowed. |
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amd_iommu= [HW,X86-64] |
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Pass parameters to the AMD IOMMU driver in the system. Possible values are: |
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fullflush - enable flushing of IO/TLB entries when they are unmapped. Otherwise they are flushed before they will be reused, which is a lot of faster |
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off - do not initialize any AMD IOMMU found in the system |
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force_isolation - Force device isolation for all devices. The IOMMU driver is not allowed anymore to lift isolation requirements as needed. This option does not override iommu=pt |
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amd_iommu_dump= [HW,X86-64] Enable AMD IOMMU driver option to dump the ACPI table for AMD IOMMU. With this option enabled, AMD IOMMU driver will print ACPI tables for AMD IOMMU during IOMMU initialization. |
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amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: <a>,<b> |
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See also Documentation/input/joystick.txt |
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analog.map= [HW,JOY] Analog joystick and gamepad support Specifies type or capabilities of an analog joystick connected to one of 16 gameports Format: <type1>,<type2>,..<type16> |
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apc= [HW,SPARC] Power management functions (SPARCstation-4/5 + deriv.) |
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Format: noidle Disable APC CPU standby support. SPARCstation-Fox does not play well with APC CPU idle - disable it if you have APC and your system crashes randomly. |
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apic= [APIC,X86-32] Advanced Programmable Interrupt Controller |
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Change the output verbosity whilst booting |
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Format: { quiet (default) | verbose | debug } Change the amount of debugging information output when initialising the APIC and IO-APIC components. |
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autoconf= [IPV6] See Documentation/networking/ipv6.txt. |
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show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller Limit apic dumping. The parameter defines the maximal number of local apics being dumped. Also it is possible to set it to "all" by meaning -- no limit here. Format: { 1 (default) | 2 | ... | all }. The parameter valid if only apic=debug or apic=verbose is specified. Example: apic=debug show_lapic=all |
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apm= [APM] Advanced Power Management |
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See header of arch/x86/kernel/apm_32.c. |
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arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards Format: <io>,<irq>,<nodeID> ataflop= [HW,M68k] atarimouse= [HW,MOUSE] Atari Mouse |
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atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess, EzKey and similar keyboards atkbd.reset= [HW] Reset keyboard during initialization |
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atkbd.set= [HW] Select keyboard code set Format: <int> (2 = AT (default), 3 = PS/2) |
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atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar keyboards atkbd.softraw= [HW] Choose between synthetic and real raw mode Format: <bool> (0 = real, 1 = synthetic (default)) |
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atkbd.softrepeat= [HW] Use software keyboard repeat |
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baycom_epp= [HW,AX25] Format: <io>,<mode> |
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baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem Format: <io>,<mode> See header of drivers/net/hamradio/baycom_par.c. |
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baycom_ser_fdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Full Duplex Mode) |
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Format: <io>,<irq>,<mode>[,<baud>] See header of drivers/net/hamradio/baycom_ser_fdx.c. |
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baycom_ser_hdx= [HW,AX25] BayCom Serial Port AX.25 Modem (Half Duplex Mode) |
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Format: <io>,<irq>,<mode> See header of drivers/net/hamradio/baycom_ser_hdx.c. |
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boot_delay= Milliseconds to delay each printk during boot. Values larger than 10 seconds (10000) are changed to no delay (0). Format: integer |
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bootmem_debug [KNL] Enable bootmem allocator debug messages. |
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bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards) |
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bttv.radio= Most important insmod options are available as kernel args too. |
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bttv.pll= See Documentation/video4linux/bttv/Insmod-options |
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bttv.tuner= |
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bulk_remove=off [PPC] This parameter disables the use of the pSeries firmware feature for flushing multiple hpte entries at a time. |
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c101= [NET] Moxa C101 synchronous serial card |
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cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection. |
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|
467 468 469 470 471 |
Sometimes CPU hardware bugs make them report the cache size incorrectly. The kernel will attempt work arounds to fix known problems, but for some CPUs it is not possible to determine what the correct size should be. This option provides an override for these situations. |
14ff56bbb
|
472 473 |
ccw_timeout_log [S390] See Documentation/s390/CommonIO for details. |
1da177e4c
|
474 |
|
8bab8dded
|
475 476 477 |
cgroup_disable= [KNL] Disable a particular controller Format: {name of the controller(s) to disable} {Currently supported controllers - "memory"} |
1da177e4c
|
478 479 480 |
checkreqprot [SELINUX] Set initial checkreqprot flag value. Format: { "0" | "1" } See security/selinux/Kconfig help text. |
a99130449
|
481 482 |
0 -- check protection applied by kernel (includes any implied execute protection). |
1da177e4c
|
483 484 |
1 -- check protection requested by application. Default value is set via a kernel config option. |
a99130449
|
485 486 |
Value can be changed at runtime via /selinux/checkreqprot. |
661ca0da3
|
487 488 |
cio_ignore= [S390] See Documentation/s390/CommonIO for details. |
1e435256d
|
489 490 491 492 493 494 495 |
clk_ignore_unused [CLK] Keep all clocks already enabled by bootloader on, even if no driver has claimed them. This 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. |
661ca0da3
|
496 |
|
cd4f0ef7c
|
497 |
clock= [BUGS=X86-32, HW] gettimeofday clocksource override. |
734efb467
|
498 |
[Deprecated] |
3f6dee9b2
|
499 |
Forces specified clocksource (if available) to be used |
734efb467
|
500 |
when calculating gettimeofday(). If specified |
3f6dee9b2
|
501 |
clocksource is not available, it defaults to PIT. |
1da177e4c
|
502 |
Format: { pit | tsc | cyclone | pmtmr } |
592913ecb
|
503 |
clocksource= Override the default clocksource |
3d6ac9843
|
504 505 506 507 508 509 510 511 512 513 |
Format: <string> Override the default clocksource and use the clocksource with the name specified. Some clocksource names to choose from, depending on the platform: [all] jiffies (this is the base, fallback clocksource) [ACPI] acpi_pm [ARM] imx_timer1,OSTS,netx_timer,mpu_timer2, pxa_timer,timer3,32k_counter,timer0_1 [AVR32] avr32 |
9863c90f6
|
514 |
[X86-32] pit,hpet,tsc; |
3d6ac9843
|
515 516 517 518 519 520 521 |
scx200_hrt on Geode; cyclone on IBM x440 [MIPS] MIPS [PARISC] cr16 [S390] tod [SH] SuperH [SPARC64] tick [X86-64] hpet,tsc |
ac72e7888
|
522 523 |
clearcpuid=BITNUM [X86] Disable CPUID feature X for the kernel. See |
07983f0e3
|
524 525 |
arch/x86/include/asm/cpufeature.h for the valid bit numbers. Note the Linux specific bits are not necessarily |
ac72e7888
|
526 527 528 529 530 531 532 533 |
stable over kernel options, but the vendor specific ones should be. Also note that user programs calling CPUID directly or using the feature without checking anything will still see it. This just prevents it from being used by the kernel or shown in /proc/cpuinfo. Also note the kernel might malfunction if you disable some critical bits. |
c64be2bb1
|
534 535 536 537 |
cma=nn[MG] [ARM,KNL] Sets the size of kernel global memory area for contiguous memory allocations. For more information, see include/linux/dma-contiguous.h |
14f966e79
|
538 539 540 541 542 543 |
cmo_free_hint= [PPC] Format: { yes | no } Specify whether pages are marked as being inactive when they are freed. This is used in CMO environments to determine OS memory pressure for page stealing by a hypervisor. Default: yes |
c79095092
|
544 545 |
coherent_pool=nn[KMG] [ARM,KNL] Sets the size of memory pool for coherent, atomic dma |
e9da6e990
|
546 |
allocations, by default set to 256K. |
c79095092
|
547 |
|
6cececfce
|
548 |
code_bytes [X86] How many bytes of object code to print |
a25bd9496
|
549 |
in an oops report. |
86c418374
|
550 551 |
Range: 0 - 8192 Default: 64 |
1da177e4c
|
552 |
com20020= [HW,NET] ARCnet - COM20020 chipset |
a99130449
|
553 554 |
Format: <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] |
1da177e4c
|
555 556 557 |
com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) Format: <io>[,<irq>] |
a99130449
|
558 559 |
com90xx= [HW,NET] ARCnet - COM90xx chipset (memory-mapped buffers) |
1da177e4c
|
560 561 562 563 |
Format: <io>[,<irq>[,<memstart>]] condev= [HW,S390] console device conmode= |
a99130449
|
564 |
|
1da177e4c
|
565 566 567 568 569 |
console= [KNL] Output console device and options. tty<n> Use the virtual console device <n>. ttyS<n>[,options] |
f1a1c2dc2
|
570 |
ttyUSB0[,options] |
1da177e4c
|
571 |
Use the specified serial port. The options are of |
f1a1c2dc2
|
572 573 574 575 576 577 578 579 580 |
the form "bbbbpnf", where "bbbb" is the baud rate, "p" is parity ("n", "o", or "e"), "n" is number of bits, and "f" is flow control ("r" for RTS or omit it). Default is "9600n8". See Documentation/serial-console.txt for more information. See Documentation/networking/netconsole.txt for an alternative. |
1da177e4c
|
581 |
|
18a8bd949
|
582 583 |
uart[8250],io,<addr>[,options] uart[8250],mmio,<addr>[,options] |
1da177e4c
|
584 585 586 587 |
Start an early, polled-mode console on the 8250/16550 UART at the specified I/O port or MMIO address, switching to the matching ttyS device later. The options are the same as for ttyS, above. |
a2fd64191
|
588 589 |
hvc<n> Use the hypervisor console device <n>. This is for both Xen and PowerPC hypervisors. |
1da177e4c
|
590 |
|
f7511d5f6
|
591 592 593 594 |
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. |
f324edc85
|
595 596 597 |
consoleblank= [KNL] The console blank (screen saver) timeout in seconds. Defaults to 10*60 = 10mins. A value of 0 disables the blank timer. |
4cb0e11b1
|
598 599 600 601 |
coredump_filter= [KNL] Change the default value for /proc/<pid>/coredump_filter. See also Documentation/filesystems/proc.txt. |
62027aea2
|
602 603 |
cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system |
1da177e4c
|
604 |
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver |
a99130449
|
605 606 |
Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] |
1da177e4c
|
607 |
|
6f21e6463
|
608 609 610 611 612 613 614 |
crashkernel=size[KMG][@offset[KMG]] [KNL] Using kexec, Linux can switch to a 'crash kernel' upon panic. This parameter reserves the physical memory region [offset, offset + size] for that kernel image. If '@offset' is omitted, then a suitable offset is selected automatically. Check Documentation/kdump/kdump.txt for further details. |
dc009d924
|
615 |
|
fb391599f
|
616 617 618 619 620 |
crashkernel=range1:size1[,range2:size2,...][@offset] [KNL] Same as above, but depends on the memory in the running system. The syntax of range is start-[end] where start and end are both a memory unit (amount[KMG]). See also |
6f21e6463
|
621 |
Documentation/kdump/kdump.txt for an example. |
fb391599f
|
622 |
|
adbc742bf
|
623 |
crashkernel=size[KMG],high |
55a20ee78
|
624 625 626 627 628 629 |
[KNL, x86_64] range could be above 4G. Allow kernel to allocate physical memory region from top, so could be above 4G if system have more than 4G ram installed. Otherwise memory region will be allocated below 4G, if available. It will be ignored if crashkernel=X is specified. |
adbc742bf
|
630 631 632 |
crashkernel=size[KMG],low [KNL, x86_64] range under 4G. When crashkernel=X,high is passed, kernel could allocate physical memory region |
c729de8fc
|
633 634 635 636 637 638 639 |
above 4G, that cause second kernel crash on system that require some amount of low memory, e.g. swiotlb requires at least 64M+32K low memory. Kernel would try to allocate 72M below 4G automatically. This one let user to specify own low range under 4G for second kernel instead. 0: to disable low allocation. |
adbc742bf
|
640 |
It will be ignored when crashkernel=X,high is not used |
55a20ee78
|
641 |
or memory reserved is below 4G. |
c729de8fc
|
642 |
|
1da177e4c
|
643 644 645 646 647 |
cs89x0_dma= [HW,NET] Format: <dma> cs89x0_media= [HW,NET] Format: { rj45 | aui | bnc } |
a99130449
|
648 |
|
a99130449
|
649 |
dasd= [HW,NET] |
1da177e4c
|
650 651 652 653 654 655 |
See header of drivers/s390/block/dasd_devmap.c. 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 |
a648ec05b
|
656 657 |
ddebug_query= [KNL,DYNAMIC_DEBUG] Enable debug messages at early boot time. See Documentation/dynamic-debug-howto.txt for |
29e36c9ff
|
658 |
details. Deprecated, see dyndbg. |
a648ec05b
|
659 |
|
1da177e4c
|
660 |
debug [KNL] Enable kernel debugging (events log level). |
cae2ed9aa
|
661 662 663 664 665 666 667 668 |
debug_locks_verbose= [KNL] verbose self-tests Format=<0|1> Print debugging info while doing the locking API self-tests. We default to 0 (no extra messages), setting it to 1 will print _a lot_ more information - normally only useful to kernel developers. |
3ac7fe5a4
|
669 |
debug_objects [KNL] Enable object debugging |
3e8ebb5c4
|
670 671 |
no_debug_objects [KNL] Disable object debugging |
c0a32fc5a
|
672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 |
debug_guardpage_minorder= [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this parameter allows control of the order of pages that will be intentionally kept free (and hence protected) by the buddy allocator. Bigger value increase the probability of catching random memory corruption, but reduce the amount of memory for normal system use. The maximum possible value is MAX_ORDER/2. Setting this parameter to 1 or 2 should be enough to identify most random memory corruption problems caused by bugs in kernel or driver code when a CPU writes to (or reads from) a random memory location. Note that there exists a class of memory corruptions problems caused by buggy H/W or F/W or by drivers badly programing DMA (basically when memory is written at bus level and the CPU MMU is bypassed) which are not detectable by CONFIG_DEBUG_PAGEALLOC, hence this option will not help tracking down these problems. |
d3af01f18
|
690 |
debugpat [X86] Enable PAT debugging |
2d27a9661
|
691 |
decnet.addr= [HW,NET] |
1da177e4c
|
692 693 |
Format: <area>[,<node>] See also Documentation/networking/decnet.txt. |
0cb55ad2a
|
694 695 696 697 698 699 700 |
default_hugepagesz= [same as hugepagesz=] The size of the default HugeTLB page size. This is the size represented by the legacy /proc/ hugepages APIs, used for SHM, and default size when mounting hugetlbfs filesystems. Defaults to the default architecture's huge page size if not specified. |
55ff9780e
|
701 |
|
1da177e4c
|
702 703 |
dhash_entries= [KNL] Set number of hash buckets for dentry cache. |
a99130449
|
704 |
|
1da177e4c
|
705 706 707 708 709 |
digi= [HW,SERIAL] IO parameters + enable/disable command. digiepca= [HW,SERIAL] See drivers/char/README.epca and |
31c00fc15
|
710 |
Documentation/serial/digiepca.txt. |
1da177e4c
|
711 |
|
b0f83b280
|
712 713 |
disable= [IPV6] See Documentation/networking/ipv6.txt. |
4e8b0cf46
|
714 715 716 |
disable_ddw [PPC/PSERIES] Disable Dynamic DMA Window support. Use this if to workaround buggy firmware. |
b0f83b280
|
717 718 |
disable_ipv6= [IPV6] See Documentation/networking/ipv6.txt. |
95ffa2438
|
719 |
disable_mtrr_cleanup [X86] |
95ffa2438
|
720 721 |
The kernel tries to adjust MTRR layout from continuous to discrete, to make X server driver able to add WB |
0cb55ad2a
|
722 |
entry later. This parameter disables that. |
95ffa2438
|
723 |
|
093af8d7f
|
724 |
disable_mtrr_trim [X86, Intel and AMD only] |
99fc8d424
|
725 726 727 728 |
By default the kernel will trim any uncacheable memory out of your available memory pool based on MTRR settings. This parameter disables that behavior, possibly causing your machine to run very slowly. |
6cececfce
|
729 |
disable_timer_pin_1 [X86] |
0cb55ad2a
|
730 731 |
Disable PIN 1 of APIC timer Can be useful to work around chipset bugs. |
0cb55ad2a
|
732 733 734 735 736 737 738 739 740 |
dma_debug=off If the kernel is compiled with DMA_API_DEBUG support, this option disables the debugging code at boot. dma_debug_entries=<number> This option allows to tune the number of preallocated entries for DMA-API debugging code. One entry is required per DMA-API allocation. Use this if the DMA-API debugging code disables itself because the architectural default is too low. |
1745de5e5
|
741 742 743 744 745 746 |
dma_debug_driver=<driver_name> With this option the DMA-API debugging driver filter feature can be enabled at boot time. Just pass the driver to filter for as the parameter. The filter can be disabled or changed to another driver later using sysfs. |
da0df92b5
|
747 748 749 750 751 752 753 754 755 756 757 758 759 760 |
drm_kms_helper.edid_firmware=[<connector>:]<file> Broken monitors, graphic adapters and KVMs may send no or incorrect EDID data sets. This parameter allows to specify an EDID data set in the /lib/firmware directory that is used instead. Generic built-in EDID data sets are used, if one of edid/1024x768.bin, edid/1280x1024.bin, edid/1680x1050.bin, or edid/1920x1080.bin is given and no file with the same name exists. Details and instructions how to build your own EDID data are available in Documentation/EDID/HOWTO.txt. An EDID data set will only be used for a particular connector, if its name and a colon are prepended to the EDID name. |
1da177e4c
|
761 |
dscc4.setup= [NET] |
29e36c9ff
|
762 763 764 765 |
dyndbg[="val"] [KNL,DYNAMIC_DEBUG] module.dyndbg[="val"] Enable debug messages at boot time. See Documentation/dynamic-debug-howto.txt for details. |
0cb55ad2a
|
766 767 768 |
earlycon= [KNL] Output early console device and options. uart[8250],io,<addr>[,options] uart[8250],mmio,<addr>[,options] |
1917ac76e
|
769 |
uart[8250],mmio32,<addr>[,options] |
0cb55ad2a
|
770 771 |
Start an early, polled-mode console on the 8250/16550 UART at the specified I/O port or MMIO address. |
162902466
|
772 773 |
MMIO inter-register address stride is either 8-bit (mmio) or 32-bit (mmio32). |
0cb55ad2a
|
774 |
The options are the same as for ttyS, above. |
147ea0911
|
775 |
earlyprintk= [X86,SH,BLACKFIN,ARM] |
1da177e4c
|
776 |
earlyprintk=vga |
2482a92e7
|
777 |
earlyprintk=xen |
1da177e4c
|
778 |
earlyprintk=serial[,ttySn[,baudrate]] |
147ea0911
|
779 |
earlyprintk=serial[,0x...[,baudrate]] |
ea3acb199
|
780 |
earlyprintk=ttySn[,baudrate] |
9780bc41d
|
781 |
earlyprintk=dbgp[debugController#] |
1da177e4c
|
782 |
|
147ea0911
|
783 784 785 |
earlyprintk is useful when the kernel crashes before the normal console is initialized. It is not enabled by default because it has some cosmetic problems. |
a99130449
|
786 |
Append ",keep" to not disable it when the real console |
1da177e4c
|
787 |
takes over. |
5c05917e7
|
788 |
Only vga or serial or usb debug port at a time. |
1da177e4c
|
789 |
|
147ea0911
|
790 791 792 793 794 795 796 797 |
Currently only ttyS0 and ttyS1 may be specified by name. Other I/O ports may be explicitly specified on some architectures (x86 and arm at least) by replacing ttySn with an I/O port address, like this: earlyprintk=serial,0x1008,115200 You can find the port for a given device in /proc/tty/driver/serial: 2: uart:ST16650V2 port:00001008 irq:18 ... |
1da177e4c
|
798 799 800 801 802 803 |
Interaction with the standard serial driver is not very good. The VGA output is eventually overwritten by the real console. |
2482a92e7
|
804 |
The xen output can only be used by Xen PV guests. |
9731191f7
|
805 806 |
ekgdboc= [X86,KGDB] Allow early kernel console debugging ekgdboc=kbd |
25985edce
|
807 |
This is designed to be used in conjunction with |
9731191f7
|
808 |
the boot argument: earlyprintk=vga |
1da177e4c
|
809 |
edd= [EDD] |
8c4dd6068
|
810 |
Format: {"off" | "on" | "skip[mbr]"} |
1da177e4c
|
811 |
|
8c58bf3ee
|
812 813 814 815 816 |
efi_no_storage_paranoia [EFI; X86] Using this parameter you can use more than 50% of your efi variable storage. Use this parameter only if you are really sure that your UEFI does sane gc and fulfills the spec otherwise your board may brick. |
1da177e4c
|
817 818 |
eisa_irq_edge= [PARISC,HW] See header of drivers/parisc/eisa.c. |
cd4f0ef7c
|
819 |
elanfreq= [X86-32] |
1da177e4c
|
820 |
See comment before function elanfreq_setup() in |
71f77055d
|
821 |
arch/x86/kernel/cpu/cpufreq/elanfreq.c. |
1da177e4c
|
822 823 |
elevator= [IOSCHED] |
17a9e7bba
|
824 |
Format: {"cfq" | "deadline" | "noop"} |
395cf9691
|
825 |
See Documentation/block/cfq-iosched.txt and |
a99130449
|
826 |
Documentation/block/deadline-iosched.txt for details. |
d3bf37955
|
827 |
elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] |
a99130449
|
828 |
Specifies physical address of start of kernel core |
d3bf37955
|
829 830 |
image elf header and optionally the size. Generally kexec loader will pass this option to capture kernel. |
aac04b32f
|
831 |
See Documentation/kdump/kdump.txt for details. |
1da177e4c
|
832 |
|
0cb55ad2a
|
833 834 835 836 |
enable_mtrr_cleanup [X86] The kernel tries to adjust MTRR layout from continuous to discrete, to make X server driver able to add WB entry later. This parameter enables that. |
ca1eda2d7
|
837 |
enable_timer_pin_1 [X86] |
0cb55ad2a
|
838 839 840 841 |
Enable PIN 1 of APIC timer Can be useful to work around chipset bugs (in particular on some ATI chipsets). The kernel tries to set a reasonable default. |
1da177e4c
|
842 843 844 845 846 847 848 |
enforcing [SELINUX] Set initial enforcing status. Format: {"0" | "1"} See security/selinux/Kconfig help text. 0 -- permissive (log only, no denials). 1 -- enforcing (deny and log). Default value is 0. Value can be changed at runtime via /selinux/enforce. |
a08f82d08
|
849 850 851 |
erst_disable [ACPI] Disable Error Record Serialization Table (ERST) support. |
1da177e4c
|
852 853 854 |
ether= [HW,NET] Ethernet cards parameters This option is obsoleted by the "netdev=" option, which has equivalent usage. See its documentation for details. |
7102ebcd6
|
855 856 857 858 |
evm= [EVM] Format: { "fix" } Permit 'security.evm' to be updated regardless of current integrity status. |
de1ba09b2
|
859 860 861 862 863 |
failslab= fail_page_alloc= fail_make_request=[KNL] General fault injection mechanism. Format: <interval>,<probability>,<space>,<times> |
395cf9691
|
864 |
See also Documentation/fault-injection/. |
de1ba09b2
|
865 |
|
1da177e4c
|
866 |
floppy= [HW] |
31c00fc15
|
867 |
See Documentation/blockdev/floppy.txt. |
1da177e4c
|
868 |
|
f13ae30e1
|
869 870 871 872 873 |
force_pal_cache_flush [IA-64] Avoid check_sal_cache_flush which may hang on buggy SAL_CACHE_FLUSH implementations. Using this parameter will force ia64_sal_cache_flush to call ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. |
d9e540762
|
874 |
ftrace=[tracer] |
2af15d6a4
|
875 |
[FTRACE] will set and start the specified tracer |
d9e540762
|
876 877 |
as early as possible in order to facilitate early boot debugging. |
cecbca96d
|
878 |
ftrace_dump_on_oops[=orig_cpu] |
2af15d6a4
|
879 |
[FTRACE] will dump the trace buffers on oops. |
cecbca96d
|
880 881 882 883 |
If no parameter is passed, ftrace will dump buffers of all CPUs, but if you pass orig_cpu, it will dump only the buffer of the CPU that triggered the oops. |
2af15d6a4
|
884 885 886 887 888 889 |
ftrace_filter=[function-list] [FTRACE] Limit the functions traced by the function tracer at boot up. function-list is a comma separated list of functions. This list can be changed at run time by the set_ftrace_filter file in the debugfs |
162902466
|
890 |
tracing directory. |
2af15d6a4
|
891 892 893 894 895 896 |
ftrace_notrace=[function-list] [FTRACE] Do not trace the functions specified in function-list. This list can be changed at run time by the set_ftrace_notrace file in the debugfs tracing directory. |
d9e540762
|
897 |
|
369bc18f9
|
898 899 900 901 902 903 |
ftrace_graph_filter=[function-list] [FTRACE] Limit the top level callers functions traced by the function graph tracer at boot up. function-list is a comma separated list of functions that can be changed at run time by the set_graph_function file in the debugfs tracing directory. |
1da177e4c
|
904 905 906 907 908 909 910 |
gamecon.map[2|3]= [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 gamma= [HW,DRM] |
aaf230424
|
911 912 913 |
gart_fix_e820= [X86_64] disable the fix e820 for K8 GART Format: off | on default: on |
2521f2c22
|
914 915 916 917 918 |
gcov_persist= [GCOV] When non-zero (default), profiling data for kernel modules is saved and remains accessible via debugfs, even when the module is unloaded/reloaded. When zero, profiling data is discarded and associated debugfs files are removed at module unload time. |
1da177e4c
|
919 920 |
gpt [EFI] Forces disk with valid GPT signature but invalid Protective MBR to be treated as GPT. |
6cec9b07f
|
921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 |
grcan.enable0= [HW] Configuration of physical interface 0. Determines the "Enable 0" bit of the configuration register. Format: 0 | 1 Default: 0 grcan.enable1= [HW] Configuration of physical interface 1. Determines the "Enable 0" bit of the configuration register. Format: 0 | 1 Default: 0 grcan.select= [HW] Select which physical interface to use. Format: 0 | 1 Default: 0 grcan.txsize= [HW] Sets the size of the tx buffer. Format: <unsigned int> such that (txsize & ~0x1fffc0) == 0. Default: 1024 grcan.rxsize= [HW] Sets the size of the rx buffer. Format: <unsigned int> such that (rxsize & ~0x1fffc0) == 0. Default: 1024 |
1da177e4c
|
938 939 |
hashdist= [KNL,NUMA] Large hashes allocated during boot are distributed across NUMA nodes. Defaults on |
162902466
|
940 |
for 64-bit NUMA, off otherwise. |
a99130449
|
941 |
Format: 0 | 1 (for off | on) |
1da177e4c
|
942 943 944 945 946 |
hcl= [IA-64] SGI's Hardware Graph compatibility layer hd= [EIDE] (E)IDE hard drive subsystem geometry Format: <cyl>,<head>,<sect> |
ea8c071ca
|
947 948 949 950 |
hest_disable [ACPI] Disable Hardware Error Source Table (HEST) support; corresponding firmware-first mode error processing logic will be disabled. |
1da177e4c
|
951 952 953 954 |
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact size of <nn>. This works even on boxes that have no highmem otherwise. This also works to reduce highmem size on bigger boxes. |
54cdfdb47
|
955 956 957 |
highres= [KNL] Enable/disable high resolution timer mode. Valid parameters: "on", "off" Default: "on" |
1da177e4c
|
958 959 |
hisax= [HW,ISDN] See Documentation/isdn/README.HiSax. |
0cb55ad2a
|
960 961 962 963 964 965 966 967 968 |
hlt [BUGS=ARM,SH] hpet= [X86-32,HPET] option to control HPET usage Format: { enable (default) | disable | force | verbose } disable: disable HPET and use PIT instead force: allow force enabled of undocumented chips (ICH4, VIA, nVidia) verbose: show contents of HPET registers during setup |
b4718e628
|
969 970 |
hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot. hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages. |
0d9ea7544
|
971 972 973 974 975 |
On x86-64 and powerpc, this option can be specified multiple times interleaved with hugepages= to reserve huge pages of different sizes. Valid pages sizes on x86-64 are 2M (when the CPU supports "pse") and 1G (when the CPU supports the "pdpe1gb" cpuinfo flag) |
b4718e628
|
976 977 |
Note that 1GB pages can only be allocated at boot time using hugepages= and not freed afterwards. |
6902aa84f
|
978 |
|
555d61d65
|
979 980 |
hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC) terminal devices. Valid values: 0..8 |
431429ff7
|
981 982 983 |
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. |
cef7125de
|
984 |
|
fdabf525b
|
985 986 987 |
hwthread_map= [METAG] Comma-separated list of Linux cpu id to hardware thread id mappings. Format: <cpu>:<hwthread> |
7bf693951
|
988 989 990 991 992 |
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. |
3a853fb93
|
993 |
i2c_bus= [HW] Override the default board specific I2C bus speed |
7954763bb
|
994 995 |
or register an additional I2C bus that is not registered from board initialization code. |
3a853fb93
|
996 997 |
Format: <bus_id>,<clkrate> |
36d957392
|
998 |
i8042.debug [HW] Toggle i8042 debug mode |
1da177e4c
|
999 |
i8042.direct [HW] Put keyboard port into non-translated mode |
84eb8d060
|
1000 1001 |
i8042.dumbkbd [HW] Pretend that controller can only read data from keyboard and cannot control its state |
1da177e4c
|
1002 1003 |
(Don't attempt to blink the leds) i8042.noaux [HW] Don't check for auxiliary (== mouse) port |
945ef0d42
|
1004 |
i8042.nokbd [HW] Don't check/create keyboard port |
75d08c789
|
1005 1006 |
i8042.noloop [HW] Disable the AUX Loopback command while probing for the AUX port |
1da177e4c
|
1007 1008 1009 1010 |
i8042.nomux [HW] Don't check presence of an active multiplexing controller i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX controllers |
24775d652
|
1011 |
i8042.notimeout [HW] Ignore timeout condition signalled by controller |
1da177e4c
|
1012 1013 1014 1015 |
i8042.reset [HW] Reset the controller during init and cleanup i8042.unlock [HW] Unlock (ignore) the keylock i810= [HW,DRM] |
e70c9d5e6
|
1016 1017 1018 |
i8k.ignore_dmi [HW] Continue probing hardware even if DMI data indicates that the driver is running on unsupported hardware. |
1da177e4c
|
1019 1020 1021 1022 1023 1024 1025 |
i8k.force [HW] Activate i8k driver even if SMM BIOS signature does not match list of supported models. i8k.power_status [HW] Report power status in /proc/i8k (disabled by default) i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN capability is set. |
4dca20efb
|
1026 |
i915.invert_brightness= |
7bd90909b
|
1027 1028 |
[DRM] Invert the sense of the variable that is used to set the brightness of the panel backlight. Normally a |
4dca20efb
|
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 |
brightness value of 0 indicates backlight switched off, and the maximum of the brightness value sets the backlight to maximum brightness. If this parameter is set to 0 (default) and the machine requires it, or this parameter is set to 1, a brightness value of 0 sets the backlight to maximum brightness, and the maximum of the brightness value switches the backlight off. -1 -- never invert brightness 0 -- machine default 1 -- force brightness inversion |
7bd90909b
|
1039 |
|
1da177e4c
|
1040 1041 |
icn= [HW,ISDN] Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] |
0af80c04e
|
1042 1043 |
ide-core.nodma= [HW] (E)IDE subsystem Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc |
075affcbe
|
1044 1045 |
.vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr .cdrom .chs .ignore_cable are additional options |
1c10e9382
|
1046 |
See Documentation/ide/ide.txt. |
1da177e4c
|
1047 |
|
0cb55ad2a
|
1048 1049 |
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem Claim all unknown PCI IDE storage controllers. |
f039b7547
|
1050 |
idle= [X86] |
69fb3676d
|
1051 |
Format: idle=poll, idle=halt, idle=nomwait |
ada9cfdd1
|
1052 1053 1054 1055 |
Poll forces a polling idle loop that can slightly improve the performance of waking up a idle CPU, but will use a lot of power and make the system run hot. Not recommended. |
ada9cfdd1
|
1056 |
idle=halt: Halt is forced to be used for CPU idle. |
c1e3b377a
|
1057 |
In such case C2/C3 won't be used again. |
ada9cfdd1
|
1058 |
idle=nomwait: Disable mwait for CPU C-states |
a99130449
|
1059 |
|
792908225
|
1060 1061 1062 |
ignore_loglevel [KNL] Ignore loglevel setting - this will print /all/ kernel messages to the console. Useful for debugging. |
0eca6b7c7
|
1063 1064 1065 |
We also add it as printk module parameter, so users could change it dynamically, usually by /sys/module/printk/parameters/ignore_loglevel. |
792908225
|
1066 |
|
1da177e4c
|
1067 1068 |
ihash_entries= [KNL] Set number of hash buckets for inode cache. |
2fe5d6def
|
1069 1070 1071 |
ima_appraise= [IMA] appraise integrity measurements Format: { "off" | "enforce" | "fix" } default: "enforce" |
07f6a7941
|
1072 1073 1074 |
ima_appraise_tcb [IMA] The builtin appraise policy appraises all files owned by uid=0. |
3323eec92
|
1075 |
ima_hash= [IMA] |
a9ed83a58
|
1076 |
Format: { "sha1" | "md5" } |
3323eec92
|
1077 |
default: "sha1" |
5789ba3bd
|
1078 1079 1080 1081 1082 |
ima_tcb [IMA] Load a policy which meets the needs of the Trusted Computing Base. This means IMA will measure all programs exec'd, files mmap'd for exec, and all files opened for read by uid=0. |
1da177e4c
|
1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 |
init= [KNL] Format: <full_path> Run specified binary instead of /sbin/init as init process. initcall_debug [KNL] Trace initcalls as they are executed. Useful for working out where the kernel is dying during startup. initrd= [BOOT] Specify the location of the initial ramdisk inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver Format: <irq> |
6bb2ff846
|
1096 |
int_pln_enable [x86] Enable power limit notification interrupt |
d726d8d71
|
1097 1098 1099 1100 |
integrity_audit=[IMA] Format: { "0" | "1" } 0 -- basic integrity auditing messages. (Default) 1 -- additional integrity auditing messages. |
ba3959276
|
1101 |
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option |
0cd5c3c80
|
1102 1103 |
on Enable intel iommu driver. |
ba3959276
|
1104 1105 1106 1107 1108 1109 1110 1111 |
off Disable intel iommu driver. igfx_off [Default Off] By default, gfx is mapped as normal device. If a gfx device has a dedicated DMAR unit, the DMAR unit is bypassed by not enabling DMAR with this option. In this case, gfx device will use physical address for DMA. |
7d3b03ce7
|
1112 1113 |
forcedac [x86_64] With this option iommu will not optimize to look |
162902466
|
1114 |
for io virtual address below 32-bit forcing dual |
7d3b03ce7
|
1115 |
address cycle on pci bus for cards supporting greater |
162902466
|
1116 1117 |
than 32-bit addressing. The default is to look for translation below 32-bit and if not available |
7d3b03ce7
|
1118 |
then look in the higher range. |
5e0d2a6fc
|
1119 1120 1121 1122 |
strict [Default Off] With this option on every unmap_single operation will result in a hardware IOTLB flush operation as opposed to batching them for performance. |
6dd9a7c73
|
1123 1124 1125 1126 |
sp_off [Default Off] By default, super page will be supported if Intel IOMMU has the capability. With this option, super page will not be supported. |
2e92c7ad8
|
1127 1128 1129 1130 |
intel_idle.max_cstate= [KNL,HW,ACPI,X86] 0 disables intel_idle and fall back on acpi_idle. 1 to 6 specify maximum depth of C-state. |
6be264986
|
1131 1132 1133 1134 |
intel_pstate= [X86] disable Do not enable intel_pstate as the default scaling driver for the supported processors |
d1423d567
|
1135 |
intremap= [X86-64, Intel-IOMMU] |
d1423d567
|
1136 1137 1138 |
on enable Interrupt Remapping (default) off disable Interrupt Remapping nosid disable Source ID checking |
41750d31f
|
1139 1140 |
no_x2apic_optout BIOS x2APIC opt-out request will be ignored |
d1423d567
|
1141 |
|
0cb55ad2a
|
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 |
iomem= Disable strict checking of access to MMIO memory strict regions from userspace. relaxed iommu= [x86] off force noforce biomerge panic nopanic merge nomerge forcesac soft |
bcb71abe7
|
1157 |
pt [x86, IA-64] |
bcb71abe7
|
1158 |
|
0cb55ad2a
|
1159 1160 1161 1162 |
io7= [HW] IO7 for Marvel based alpha systems See comment before marvel_specify_io7 in arch/alpha/kernel/core_marvel.c. |
6cececfce
|
1163 |
io_delay= [X86] I/O delay method |
6e7c40259
|
1164 1165 1166 1167 |
0x80 Standard port 0x80 based delay 0xed Alternate port 0xed based delay (needed on some systems) |
b02aae9cf
|
1168 |
udelay |
6e7c40259
|
1169 1170 1171 |
Simple two microseconds delay none No delay |
b02aae9cf
|
1172 |
|
1da177e4c
|
1173 |
ip= [IP_PNP] |
dc7a08166
|
1174 |
See Documentation/filesystems/nfs/nfsroot.txt. |
1da177e4c
|
1175 1176 |
ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards |
c8facbb62
|
1177 1178 |
See comment before ip2_setup() in drivers/char/ip2/ip2base.c. |
1da177e4c
|
1179 |
|
200803dfe
|
1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 |
irqfixup [HW] When an interrupt is not handled search all handlers for it. Intended to get systems with badly broken firmware running. irqpoll [HW] When an interrupt is not handled search all handlers for it. Also check all handlers each timer interrupt. Intended to get systems with badly broken firmware running. |
1da177e4c
|
1190 |
isapnp= [ISAPNP] |
a99130449
|
1191 |
Format: <RDP>,<reset>,<pci_scan>,<verbosity> |
1da177e4c
|
1192 1193 |
isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. |
22f2e2801
|
1194 1195 1196 |
Format: <cpu number>,...,<cpu number> or |
b225d44e2
|
1197 1198 |
<cpu number>-<cpu number> (must be a positive range in ascending order) |
22f2e2801
|
1199 1200 |
or a mixture <cpu number>,...,<cpu number>-<cpu number> |
b225d44e2
|
1201 |
|
1da177e4c
|
1202 1203 |
This option can be used to specify one or more CPUs to isolate from the general SMP balancing and scheduling |
b225d44e2
|
1204 1205 |
algorithms. You can move a process onto or off an "isolated" CPU via the CPU affinity syscalls or cpuset. |
1da177e4c
|
1206 1207 1208 1209 |
<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 |
a99130449
|
1210 1211 1212 |
alternative -- manually setting the CPU mask of all tasks in the system -- can cause problems and suboptimal load balancer performance. |
1da177e4c
|
1213 |
|
a99130449
|
1214 |
iucv= [HW,NET] |
1da177e4c
|
1215 |
|
7d8bfa26f
|
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 |
ivrs_ioapic [HW,X86_64] Provide an override to the IOAPIC-ID<->DEVICE-ID mapping provided in the IVRS ACPI table. For example, to map IOAPIC-ID decimal 10 to PCI device 00:14.0 write the parameter as: ivrs_ioapic[10]=00:14.0 ivrs_hpet [HW,X86_64] Provide an override to the HPET-ID<->DEVICE-ID mapping provided in the IVRS ACPI table. For example, to map HPET-ID decimal 0 to PCI device 00:14.0 write the parameter as: ivrs_hpet[0]=00:14.0 |
1da177e4c
|
1229 1230 |
js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt. |
0cb55ad2a
|
1231 |
keepinitrd [HW,ARM] |
6cececfce
|
1232 |
kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
ed7ed3651
|
1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 |
specifies the amount of memory usable by the kernel for non-movable allocations. The requested amount is spread evenly throughout all nodes in the system. The remaining memory in each node is used for Movable pages. In the event, a node is too small to have both kernelcore and Movable pages, kernelcore pages will take priority and other nodes will have a larger number of kernelcore pages. The Movable zone is used for the allocation of pages that may be reclaimed or moved by the page migration subsystem. This means that HugeTLB pages may not be allocated from this zone. Note that allocations like PTEs-from-HighMem still use the HighMem zone if it exists, and the Normal zone if it does not. |
4fe1da4eb
|
1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 |
kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. Format: <Controller#>[,poll interval] The controller # is the number of the ehci usb debug port as it is probed via PCI. The poll interval is optional and is the number seconds in between each poll cycle to the debug port in case you need the functionality for interrupting the kernel with gdb or control-c on the dbgp connection. When not using this parameter you use sysrq-g to break into the kernel debugger. |
84c08fd61
|
1257 |
kgdboc= [KGDB,HW] kgdb over consoles. |
ada64e4c9
|
1258 1259 |
Requires a tty driver that supports console polling, or a supported polling keyboard driver (non-usb). |
65b5ac147
|
1260 1261 1262 1263 1264 1265 |
Serial only format: <serial_device>[,baud] keyboard only format: kbd keyboard and serial format: kbd,<serial_device>[,baud] Optional Kernel mode setting: kms, kbd format: kms,kbd kms, kbd and serial format: kms,kbd,<ser_dev>[,baud] |
6cdf6e06d
|
1266 |
|
84c08fd61
|
1267 1268 |
kgdbwait [KGDB] Stop kernel execution and enter the kernel debugger at the earliest opportunity. |
9bed90c6a
|
1269 1270 1271 |
kmac= [MIPS] korina ethernet MAC address. Configure the RouterBoard 532 series on-chip Ethernet adapter MAC address. |
04f70336c
|
1272 1273 1274 |
kmemleak= [KNL] Boot-time kmemleak enable/disable Valid arguments: on, off Default: on |
6cececfce
|
1275 |
kstack=N [X86] Print N words from the kernel stack |
0cb55ad2a
|
1276 |
in oops dumps. |
fef07aae9
|
1277 1278 |
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. Default is 0 (don't ignore, but inject #GP) |
a182d8737
|
1279 1280 |
kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit KVM MMU at runtime. |
fef07aae9
|
1281 |
Default is 0 (off) |
fef07aae9
|
1282 |
kvm-amd.nested= [KVM,AMD] Allow nested virtualization in KVM/SVM. |
8475f94ab
|
1283 |
Default is 1 (enabled) |
fef07aae9
|
1284 1285 1286 |
kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) for all guests. |
162902466
|
1287 |
Default is 1 (enabled) if in 64-bit or 32-bit PAE mode. |
fef07aae9
|
1288 |
|
fef07aae9
|
1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 |
kvm-intel.ept= [KVM,Intel] Disable extended page tables (virtualized MMU) support on capable Intel chips. Default is 1 (enabled) kvm-intel.emulate_invalid_guest_state= [KVM,Intel] Enable emulation of invalid guest states Default is 0 (disabled) kvm-intel.flexpriority= [KVM,Intel] Disable FlexPriority feature (TPR shadow). Default is 1 (enabled) |
e1a72ae28
|
1300 1301 1302 |
kvm-intel.nested= [KVM,Intel] Enable VMX nesting (nVMX). Default is 0 (disabled) |
fef07aae9
|
1303 1304 1305 1306 1307 1308 1309 1310 |
kvm-intel.unrestricted_guest= [KVM,Intel] Disable unrestricted guest feature (virtualized real and unpaged mode) on capable Intel chips. Default is 1 (enabled) kvm-intel.vpid= [KVM,Intel] Disable Virtual Processor Identification feature (tagged TLBs) on capable Intel chips. Default is 1 (enabled) |
1da177e4c
|
1311 |
l2cr= [PPC] |
a78bfbfcf
|
1312 |
l3cr= [PPC] |
cd4f0ef7c
|
1313 |
lapic [X86-32,APIC] Enable the local APIC even if BIOS |
a99130449
|
1314 |
disabled it. |
1da177e4c
|
1315 |
|
279f14614
|
1316 1317 1318 |
lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline value for LAPIC timer one-shot implementation. Default back to the programmable timer unit in the LAPIC. |
6cececfce
|
1319 |
lapic_timer_c2_ok [X86,APIC] trust the local apic timer |
ada9cfdd1
|
1320 |
in C2 power state. |
e585bef81
|
1321 |
|
fcb71f6f0
|
1322 1323 1324 1325 |
libata.dma= [LIBATA] DMA control libata.dma=0 Disable all PATA and SATA DMA libata.dma=1 PATA and SATA Disk DMA only libata.dma=2 ATAPI (CDROM) DMA only |
162902466
|
1326 |
libata.dma=4 Compact Flash DMA only |
fcb71f6f0
|
1327 1328 |
Combinations also work, so libata.dma=3 enables DMA for disks and CDROMs, but not CFs. |
162902466
|
1329 |
|
203088715
|
1330 1331 1332 |
libata.ignore_hpa= [LIBATA] Ignore HPA limit libata.ignore_hpa=0 keep BIOS limits (default) libata.ignore_hpa=1 ignore limits, using full disk |
fcb71f6f0
|
1333 |
|
78e70c237
|
1334 1335 1336 |
libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume when set. Format: <int> |
332673257
|
1337 1338 |
libata.force= [LIBATA] Force configurations. The format is comma separated list of "[ID:]VAL" where ID is |
4c44f309c
|
1339 |
PORT[.DEVICE]. PORT and DEVICE are decimal numbers |
332673257
|
1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 |
matching port, link or device. Basically, it matches the ATA ID string printed on console by libata. If the whole ID part is omitted, the last PORT and DEVICE values are used. If ID hasn't been specified yet, the configuration applies to all ports, links and devices. If only DEVICE is omitted, the parameter applies to the port and all links and devices behind it. DEVICE number of 0 either selects the first device or the first fan-out link behind PMP device. It does not select the host link. DEVICE number of 15 selects the host link and device attached to it. The VAL specifies the configuration to force. As long as there's no ambiguity shortcut notation is allowed. For example, both 1.5 and 1.5G would work for 1.5Gbps. The following configurations can be forced. * Cable type: 40c, 80c, short40c, unk, ign or sata. Any ID with matching PORT is used. * SATA link speed limit: 1.5Gbps or 3.0Gbps. * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7]. udma[/][16,25,33,44,66,100,133] notation is also allowed. * [no]ncq: Turn on or off NCQ. |
05944bdf6
|
1368 1369 |
* nohrst, nosrst, norst: suppress hard, soft and both resets. |
ca6d43b05
|
1370 1371 |
* rstonce: only attempt one reset during hot-unplug link recovery |
43c9c5918
|
1372 |
* dump_id: dump IDENTIFY data. |
966fbe193
|
1373 |
* atapi_dmadir: Enable ATAPI DMADIR bridge support |
332673257
|
1374 1375 |
If there are multiple matching configurations changing the same attribute, the last one is used. |
95f72d1ed
|
1376 |
memblock=debug [KNL] Enable memblock debug messages. |
7c4be253d
|
1377 |
|
1da177e4c
|
1378 |
load_ramdisk= [RAM] List of ramdisks to load from floppy |
31c00fc15
|
1379 |
See Documentation/blockdev/ramdisk.txt. |
1da177e4c
|
1380 |
|
a6b25b675
|
1381 1382 |
lockd.nlm_grace_period=P [NFS] Assign grace period. Format: <integer> |
1da177e4c
|
1383 |
|
a6b25b675
|
1384 1385 1386 1387 1388 1389 1390 1391 |
lockd.nlm_tcpport=N [NFS] Assign TCP port. Format: <integer> lockd.nlm_timeout=T [NFS] Assign timeout value. Format: <integer> lockd.nlm_udpport=M [NFS] Assign UDP port. Format: <integer> |
1da177e4c
|
1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 |
logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver Format: <irq> loglevel= All Kernel Messages with a loglevel smaller than the console loglevel will be printed to the console. It can also be changed with klogd or other programs. The loglevels are defined as follows: 0 (KERN_EMERG) system is unusable 1 (KERN_ALERT) action must be taken immediately 2 (KERN_CRIT) critical conditions 3 (KERN_ERR) error conditions 4 (KERN_WARNING) warning conditions 5 (KERN_NOTICE) normal but significant condition 6 (KERN_INFO) informational 7 (KERN_DEBUG) debug-level messages |
c756d08a0
|
1409 1410 1411 |
log_buf_len=n[KMG] Sets the size of the printk ring buffer, in bytes. n must be a power of two. The default size is set in the kernel config file. |
1da177e4c
|
1412 |
|
accaa24c4
|
1413 1414 1415 1416 |
logo.nologo [FB] Disables display of the built-in Linux logo. This may be used to provide more screen space for kernel log messages and is useful when debugging kernel boot problems. |
1da177e4c
|
1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 |
lp=0 [LP] Specify parallel ports to use, e.g, lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses lp=reset first parallel port). 'lp=0' disables the lp=auto printer driver. 'lp=reset' (which can be specified in addition to the ports) causes attached printers to be reset. Using lp=port1,port2,... specifies the parallel ports to associate lp devices with, starting with lp0. A port specification may be 'none' to skip that lp device, or a parport name such as 'parport0'. Specifying 'lp=auto' instead of a port specification list means that device IDs from each port should be examined, to see if an IEEE 1284-compliant printer is attached; if so, the driver will manage that printer. See also header of drivers/char/lp.c. lpj=n [KNL] Sets loops_per_jiffy to given constant, thus avoiding time-consuming boot-time autodetection (up to 250 ms per CPU). 0 enables autodetection (default). To determine the correct value for your kernel, boot with normal autodetection and see what value is printed. Note that on SMP systems the preset will be applied to all CPUs, which is likely to cause problems if your CPUs need significantly divergent settings. An incorrect value will cause delays in the kernel to be wrong, leading to unpredictable I/O errors and other breakage. Although unlikely, in the extreme case this might damage your hardware. ltpc= [NET] Format: <io>,<irq>,<dma> |
162902466
|
1450 |
machvec= [IA-64] Force the use of a particular machine-vector |
a99130449
|
1451 1452 |
(machvec) in a generic kernel. Example: machvec=hpzx1_swiotlb |
1da177e4c
|
1453 |
|
3209e70e5
|
1454 1455 1456 |
machtype= [Loongson] Share the same kernel image file between different yeeloong laptop. Example: machtype=lemote-yeeloong-2f-7inch |
0cb55ad2a
|
1457 1458 |
max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater than or equal to this physical address is ignored. |
1da177e4c
|
1459 1460 |
maxcpus= [SMP] Maximum number of processors that an SMP kernel |
61ec7567d
|
1461 1462 1463 1464 |
should make use of. maxcpus=n : n >= 0 limits the kernel to using 'n' processors. n=0 is a special case, it is equivalent to "nosmp", which also disables the IO APIC. |
1da177e4c
|
1465 |
|
d134b00b9
|
1466 1467 1468 1469 1470 1471 |
max_loop= [LOOP] The number of loop block devices that get (loop.max_loop) unconditionally pre-created at init time. The default number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead of statically allocating a predefined number, loop devices can be requested on-demand with the /dev/loop-control interface. |
2b2c37503
|
1472 |
|
cd4f0ef7c
|
1473 |
mce [X86-32] Machine Check Exception |
1da177e4c
|
1474 |
|
71cced6eb
|
1475 |
mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt |
909dd324f
|
1476 |
|
1da177e4c
|
1477 1478 |
md= [HW] RAID subsystems devices and level See Documentation/md.txt. |
a99130449
|
1479 |
|
1da177e4c
|
1480 1481 1482 |
mdacon= [MDA] Format: <first>,<last> Specifies range of consoles to be captured by the MDA. |
a99130449
|
1483 |
|
1da177e4c
|
1484 1485 1486 |
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory Amount of memory to be used when the kernel is not able to see the whole system memory or for test. |
fbb97d878
|
1487 1488 1489 1490 |
[X86] Work as limiting max address. Use together with memmap= to avoid physical address space collisions. Without memmap= PCI devices could be placed at addresses belonging to unused RAM. |
1da177e4c
|
1491 |
|
cd4f0ef7c
|
1492 |
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel |
1da177e4c
|
1493 |
memory. |
6902aa84f
|
1494 1495 1496 |
memchunk=nn[KMG] [KNL,SH] Allow user to override the default size for per-device physically contiguous DMA buffers. |
6cececfce
|
1497 |
memmap=exactmap [KNL,X86] Enable setting of an exact |
1da177e4c
|
1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 |
E820 memory map, as specified by the user. Such memmap=exactmap lines can be constructed based on BIOS output or other requirements. See the memmap=nn@ss option description. memmap=nn[KMG]@ss[KMG] [KNL] Force usage of a specific region of memory Region of memory to be used, from ss to ss+nn. memmap=nn[KMG]#ss[KMG] [KNL,ACPI] Mark specific memory as ACPI data. Region of memory to be used, from ss to ss+nn. memmap=nn[KMG]$ss[KMG] [KNL,ACPI] Mark specific memory as reserved. Region of memory to be used, from ss to ss+nn. |
1312848e9
|
1514 1515 1516 1517 |
Example: Exclude memory from 0x18690000-0x1869ffff memmap=64K$0x18690000 or memmap=0x10000$0x18690000 |
1da177e4c
|
1518 |
|
9f077871c
|
1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 |
memory_corruption_check=0/1 [X86] Some BIOSes seem to corrupt the first 64k of memory when doing things like suspend/resume. Setting this option will scan the memory looking for corruption. Enabling this will both detect corruption and prevent the kernel from using the memory being corrupted. However, its intended as a diagnostic tool; if repeatable BIOS-originated corruption always affects the same memory, you can use memmap= to prevent the kernel from using that memory. memory_corruption_check_size=size [X86] By default it checks for corruption in the low 64k, making this memory unavailable for normal use. Use this parameter to scan for corruption in more or less memory. memory_corruption_check_period=seconds [X86] By default it checks for corruption every 60 seconds. Use this parameter to check at some other rate. 0 disables periodic checking. |
caadbdce2
|
1541 |
memtest= [KNL,X86] Enable memtest |
c64df7079
|
1542 |
Format: <integer> |
c64df7079
|
1543 |
default : 0 <disable> |
9e5f6cf5f
|
1544 1545 1546 1547 1548 1549 |
Specifies the number of memtest passes to be performed. Each pass selects another test pattern from a given set of patterns. Memtest fills the memory with this pattern, validates memory contents and reserves bad memory regions that are detected. |
c64df7079
|
1550 |
|
1da177e4c
|
1551 1552 |
meye.*= [HW] Set MotionEye Camera parameters See Documentation/video4linux/meye.txt. |
8f36881b3
|
1553 1554 1555 |
mfgpt_irq= [IA-32] Specify the IRQ to use for the Multi-Function General Purpose Timers on AMD Geode platforms. |
e6c4dc6c3
|
1556 1557 1558 1559 |
mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when the BIOS has incorrectly applied a workaround. TinyBIOS version 0.98 is known to be affected, 0.99 fixes the problem by letting the user disable the workaround. |
1da177e4c
|
1560 |
mga= [HW,DRM] |
1c207f952
|
1561 1562 |
min_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory below this physical address is ignored. |
39f45d7bc
|
1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 |
mini2440= [ARM,HW,KNL] Format:[0..2][b][c][t] Default: "0tb" MINI2440 configuration specification: 0 - The attached screen is the 3.5" TFT 1 - The attached screen is the 7" TFT 2 - The VGA Shield is attached (1024x768) Leaving out the screen size parameter will not load the TFT driver, and the framebuffer will be left unconfigured. b - Enable backlight. The TFT backlight pin will be linked to the kernel VESA blanking code and a GPIO LED. This parameter is not necessary when using the VGA shield. c - Enable the s3c camera interface. t - Reserved for enabling touchscreen support. The touchscreen support is not enabled in the mainstream kernel as of 2.6.30, a preliminary port can be found in the "bleeding edge" mini2440 support kernel at http://repo.or.cz/w/linux-2.6/mini2440.git |
6b74ab97b
|
1583 1584 1585 1586 1587 1588 1589 |
mminit_loglevel= [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this parameter allows control of the logging verbosity for the additional memory initialisation checks. A value of 0 disables mminit logging and a level of 4 will log everything. Information is printed at KERN_DEBUG so loglevel=8 may also need to be specified. |
106a4ee25
|
1590 1591 1592 |
module.sig_enforce [KNL] When CONFIG_MODULE_SIG is set, this means that modules without (valid) signatures will fail to load. |
2a039be7f
|
1593 |
Note that if CONFIG_MODULE_SIG_FORCE is set, that |
106a4ee25
|
1594 |
is always true, so this option does nothing. |
1da177e4c
|
1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 |
mousedev.tap_time= [MOUSE] Maximum time between finger touching and leaving touchpad surface for touch to be considered a tap and be reported as a left button click (for touchpads working in absolute mode only). Format: <msecs> mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices reporting absolute coordinates, such as tablets mousedev.yres= [MOUSE] Vertical screen resolution, used for devices reporting absolute coordinates, such as tablets |
6cececfce
|
1605 |
movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter |
0cb55ad2a
|
1606 1607 1608 1609 1610 1611 1612 1613 |
is similar to kernelcore except it specifies the amount of memory used for migratable allocations. If both kernelcore and movablecore is specified, then kernelcore will be at *least* the specified value but may be more. If movablecore on its own is specified, the administrator must be careful that the amount of memory usable for all allocations is not too small. |
1da177e4c
|
1614 1615 |
MTD_Partition= [MTD] Format: <name>,<region-number>,<size>,<offset> |
a99130449
|
1616 1617 |
MTD_Region= [MTD] Format: <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>] |
1da177e4c
|
1618 1619 |
mtdparts= [MTD] |
c8facbb62
|
1620 |
See drivers/mtd/cmdlinepart.c. |
1da177e4c
|
1621 |
|
4e89a2d8e
|
1622 1623 1624 |
multitce=off [PPC] This parameter disables the use of the pSeries firmware feature for updating multiple TCE entries at a time. |
5988af231
|
1625 1626 1627 1628 1629 1630 1631 1632 1633 |
onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration Format: [die0_boundary][,die0_lock][,die1_boundary][,die1_lock] boundary - index of last SLC block on Flex-OneNAND. The remaining blocks are configured as MLC blocks. lock - Configure if Flex-OneNAND boundary should be locked. Once locked, the boundary cannot be changed. 1 indicates lock status, 0 indicates unlock status. |
9db829f48
|
1634 1635 1636 1637 |
mtdset= [ARM] ARM/S3C2412 JIVE boot control See arch/arm/mach-s3c2412/mach-jive.c |
1da177e4c
|
1638 |
mtouchusb.raw_coordinates= |
a99130449
|
1639 1640 |
[HW] Make the MicroTouch USB driver use raw coordinates ('y', default) or cooked coordinates ('n') |
1da177e4c
|
1641 |
|
0cb55ad2a
|
1642 |
mtrr_chunk_size=nn[KMG] [X86] |
19f594600
|
1643 |
used for mtrr cleanup. It is largest continuous chunk |
0cb55ad2a
|
1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 |
that could hold holes aka. UC entries. mtrr_gran_size=nn[KMG] [X86] Used for mtrr cleanup. It is granularity of mtrr block. Default is 1. Large value could prevent small alignment from using up MTRRs. mtrr_spare_reg_nr=n [X86] Format: <integer> Range: 0,7 : spare reg number Default : 1 Used for mtrr cleanup. It is spare mtrr entries number. Set to 2 or more if your graphical card needs more. |
1da177e4c
|
1658 |
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card |
1da177e4c
|
1659 1660 1661 1662 |
netdev= [NET] Network devices parameters Format: <irq>,<io>,<mem_start>,<mem_end>,<name> Note that mem_start is often overloaded to mean something different and driver-specific. |
a99130449
|
1663 1664 |
This usage is only documented in each driver source file if at all. |
584015727
|
1665 1666 1667 1668 |
nf_conntrack.acct= [NETFILTER] Enable connection tracking flow accounting 0 to disable accounting 1 to enable accounting |
d70a011db
|
1669 |
Default value is 0. |
584015727
|
1670 |
|
306a07536
|
1671 |
nfsaddrs= [NFS] Deprecated. Use ip= instead. |
dc7a08166
|
1672 |
See Documentation/filesystems/nfs/nfsroot.txt. |
1da177e4c
|
1673 1674 |
nfsroot= [NFS] nfs root filesystem for disk-less boxes. |
dc7a08166
|
1675 |
See Documentation/filesystems/nfs/nfsroot.txt. |
1da177e4c
|
1676 |
|
306a07536
|
1677 1678 |
nfsrootdebug [NFS] enable nfsroot debugging messages. See Documentation/filesystems/nfs/nfsroot.txt. |
a72b44222
|
1679 1680 1681 |
nfs.callback_tcpport= [NFS] set the TCP port on which the NFSv4 callback channel should listen. |
e571cbf1a
|
1682 1683 1684 1685 1686 1687 1688 |
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. |
58df095b7
|
1689 1690 1691 |
nfs.idmap_cache_timeout= [NFS] set the maximum lifetime for idmapper cache entries. |
f43bf0beb
|
1692 1693 1694 1695 1696 1697 |
nfs.enable_ino64= [NFS] enable 64-bit inode numbers. If zero, the NFS client will fake up a 32-bit inode number for the readdir() and stat() syscalls instead of returning the full 64-bit number. The default is to return 64-bit inode numbers. |
ef159e917
|
1698 1699 1700 1701 1702 1703 1704 |
nfs.max_session_slots= [NFSv4.1] Sets the maximum number of session slots the client will attempt to negotiate with the server. This limits the number of simultaneous RPC requests that the client can send to the NFSv4.1 server. Note that there is little point in setting this value higher than the max_tcp_slot_table_limit. |
b064eca2c
|
1705 |
nfs.nfs4_disable_idmapping= |
074b1d12f
|
1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 |
[NFSv4] When set to the default of '1', this option ensures that both the RPC level authentication scheme and the NFS level operations agree to use numeric uids/gids if the mount is using the 'sec=sys' security flavour. In effect it is disabling idmapping, which can make migration from legacy NFSv2/v3 systems to NFSv4 easier. Servers that do not support this mode of operation 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'. |
6f2ea7f2a
|
1717 1718 1719 1720 1721 |
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. |
b064eca2c
|
1722 |
|
db8ac8ba8
|
1723 1724 1725 1726 1727 1728 1729 |
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. |
f6de7a39c
|
1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 |
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 no guarantees that the file will remain unchanged after the locks are lost. If you want to enable the kernel legacy behaviour of attempting to recover these locks, then set this parameter to '1'. The default parameter value of '0' causes the kernel not to attempt recovery of lost locks. |
db8ac8ba8
|
1742 |
|
e9541ce8e
|
1743 1744 1745 1746 1747 1748 |
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. |
db8ac8ba8
|
1749 |
|
18d98f6c0
|
1750 1751 1752 1753 1754 |
objlayoutdriver.osd_login_prog= [NFS] [OBJLAYOUT] sets the pathname to the program which is used to automatically discover and login into new osd-targets. Please see: Documentation/filesystems/pnfs.txt for more explanations |
1e1030dcc
|
1755 |
nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take |
e7ba176b4
|
1756 1757 |
when a NMI is triggered. Format: [state][,regs][,debounce][,die] |
6cececfce
|
1758 |
nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels |
fef2c9bc1
|
1759 |
Format: [panic,][nopanic,][num] |
5dc305587
|
1760 |
Valid num: 0 |
5b9a0e14e
|
1761 |
0 - turn nmi_watchdog off |
0cb55ad2a
|
1762 |
When panic is specified, panic when an NMI watchdog |
fef2c9bc1
|
1763 1764 |
timeout occurs (or 'nopanic' to override the opposite default). |
0cb55ad2a
|
1765 1766 |
This is useful when you use a panic=... timeout and need the box quickly up again. |
1da177e4c
|
1767 |
|
bff38771e
|
1768 1769 1770 1771 |
netpoll.carrier_timeout= [NET] Specifies amount of time (in seconds) that netpoll should wait for a carrier. By default netpoll waits 4 seconds. |
cd4f0ef7c
|
1772 |
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths |
1da177e4c
|
1773 1774 |
emulation library even if a 387 maths coprocessor is present. |
0cb55ad2a
|
1775 1776 1777 1778 1779 1780 1781 1782 1783 |
no_console_suspend [HW] Never suspend the console Disable suspending of consoles during suspend and hibernate operations. Once disabled, debugging messages can reach various consoles while the rest of the system is being put to sleep (ie, while debugging driver suspend/resume hooks). This may not work reliably with all consoles, but is known to work with serial and VGA consoles. |
134620f7a
|
1784 1785 1786 1787 1788 |
To facilitate more flexible debugging, we also add console_suspend, a printk module parameter to control it. Users could use console_suspend (usually /sys/module/printk/parameters/console_suspend) to turn on/off it dynamically. |
0cb55ad2a
|
1789 |
|
c1aee215d
|
1790 1791 1792 |
noaliencache [MM, NUMA, SLAB] Disables the allocation of alien caches in the slab allocator. Saves per-node memory, but will impact performance. |
3395ee058
|
1793 |
|
a99130449
|
1794 |
noalign [KNL,ARM] |
1da177e4c
|
1795 1796 |
noapic [SMP,APIC] Tells the kernel to not make use of any IOAPICs that may be present in the system. |
5091faa44
|
1797 |
noautogroup Disable scheduler automatic task group creation. |
1da177e4c
|
1798 1799 1800 1801 |
nobats [PPC] Do not use BATs for mapping kernel lowmem on "Classic" PPC cores. nocache [ARM] |
a99130449
|
1802 |
|
0cb55ad2a
|
1803 |
noclflush [BUGS=X86] Don't use the CLFLUSH instruction |
163ecdff0
|
1804 |
nodelayacct [KNL] Disable per-task delay accounting |
1da177e4c
|
1805 |
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. |
6902aa84f
|
1806 |
nodsp [SH] Disable hardware DSP at boot time. |
6cececfce
|
1807 |
noefi [X86] Disable EFI runtime services support. |
8b2cb7a8f
|
1808 |
|
1da177e4c
|
1809 |
noexec [IA-64] |
6cececfce
|
1810 |
noexec [X86] |
f5a1b191b
|
1811 |
On X86-32 available only on PAE configured kernels. |
1da177e4c
|
1812 |
noexec=on: enable non-executable mappings (default) |
f5a1b191b
|
1813 |
noexec=off: disable non-executable mappings |
52b6179ac
|
1814 1815 1816 |
nosmap [X86] Disable SMAP (Supervisor Mode Access Prevention) even if it is supported by processor. |
de5397ad5
|
1817 |
nosmep [X86] |
52b6179ac
|
1818 |
Disable SMEP (Supervisor Mode Execution Prevention) |
de5397ad5
|
1819 |
even if it is supported by processor. |
f5a1b191b
|
1820 1821 1822 1823 1824 1825 |
noexec32 [X86-64] This affects only 32-bit executables. noexec32=on: enable non-executable mappings (default) read doesn't imply executable mappings noexec32=off: disable non-executable mappings read implies executable mappings |
1da177e4c
|
1826 |
|
6902aa84f
|
1827 |
nofpu [SH] Disable hardware FPU at boot time. |
cd4f0ef7c
|
1828 |
nofxsr [BUGS=X86-32] Disables x86 floating point extended |
4f8865112
|
1829 1830 |
register save and restore. The kernel will only save legacy floating-point registers on task switch. |
1da177e4c
|
1831 |
|
0c752a933
|
1832 1833 1834 |
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. |
5d2bd7009
|
1835 |
eagerfpu= [X86] |
e00229819
|
1836 |
on enable eager fpu restore |
5d2bd7009
|
1837 |
off disable eager fpu restore |
e00229819
|
1838 1839 |
auto selects the default scheme, which automatically enables eagerfpu restore for xsaveopt. |
5d2bd7009
|
1840 |
|
01a24d2b9
|
1841 1842 1843 |
nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or wfi(ARM) instruction doesn't work correctly and not to use it. This is also useful when using JTAG debugger. |
a99130449
|
1844 |
|
1f29fae29
|
1845 1846 1847 |
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. |
1da177e4c
|
1848 1849 1850 1851 1852 1853 |
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 interrupt wake-up latency, which may improve performance in certain environments such as networked servers or real-time systems. |
79bf2bb33
|
1854 1855 1856 |
nohz= [KNL] Boottime enable/disable dynamic ticks Valid arguments: on, off Default: on |
c5bfece2d
|
1857 1858 |
nohz_full= [KNL,BOOT] In kernels built with CONFIG_NO_HZ_FULL=y, set |
a831881be
|
1859 |
the specified list of CPUs whose tick will be stopped |
0453b435d
|
1860 1861 |
whenever possible. The boot CPU will be forced outside the range to maintain the timekeeping. |
d1e43fa5f
|
1862 1863 |
The CPUs in this range must also be included in the rcu_nocbs= set. |
a831881be
|
1864 |
|
eeee7853c
|
1865 |
noiotrap [SH] Disables trapped I/O port accesses. |
cd4f0ef7c
|
1866 |
noirqdebug [X86-32] Disables the code which attempts to detect and |
1da177e4c
|
1867 |
disable unhandled interrupt sources. |
6cececfce
|
1868 |
no_timer_check [X86,APIC] Disables the code which tests for |
8542b200c
|
1869 |
broken timer IRQ sources. |
1da177e4c
|
1870 1871 1872 1873 |
noisapnp [ISAPNP] Disables ISA PnP code. noinitrd [RAM] Tells the kernel not to load any configured initial RAM disk. |
03ea81550
|
1874 1875 |
nointremap [X86-64, Intel-IOMMU] Do not enable interrupt remapping. |
d1423d567
|
1876 |
[Deprecated - use intremap=off] |
03ea81550
|
1877 |
|
1da177e4c
|
1878 |
nointroute [IA-64] |
162902466
|
1879 |
nojitter [IA-64] Disables jitter checking for ITC timers. |
0aa366f35
|
1880 |
|
9cf4c4fcb
|
1881 |
no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver |
fd10cde92
|
1882 1883 |
no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page fault handling. |
d910f5c10
|
1884 1885 1886 |
no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. steal time is computed, but won't influence scheduler behaviour |
cd4f0ef7c
|
1887 |
nolapic [X86-32,APIC] Do not enable or use the local APIC. |
1da177e4c
|
1888 |
|
cd4f0ef7c
|
1889 |
nolapic_timer [X86-32,APIC] Do not use the local APIC timer. |
ad62ca2bd
|
1890 |
|
1da177e4c
|
1891 1892 |
noltlbs [PPC] Do not use large page/tlb entries for kernel lowmem mapping on PPC40x. |
312f1f014
|
1893 |
nomca [IA-64] Disable machine check abort handling |
cd4f0ef7c
|
1894 |
nomce [X86-32] Machine Check Exception |
abe37e5a1
|
1895 |
|
83d7384f8
|
1896 1897 |
nomfgpt [X86-32] Disable Multi-Function General Purpose Timer usage (for AMD Geode machines). |
bda626339
|
1898 1899 1900 |
nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to shutdown the other cpus. Instead use the REBOOT_VECTOR irq. |
02608bef8
|
1901 |
nomodule Disable module load |
016ddd9b5
|
1902 1903 |
nopat [X86] Disable PAT (page attribute table extension of pagetables) support. |
0cb55ad2a
|
1904 1905 |
norandmaps Don't use address space randomization. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space |
bbff2168c
|
1906 |
noreplace-paravirt [X86,IA-64,PV_OPS] Don't patch paravirt_ops |
959b4fdfe
|
1907 |
|
cd4f0ef7c
|
1908 |
noreplace-smp [X86-32,SMP] Don't replace SMP instructions |
b7fb4af06
|
1909 |
with UP alternatives |
49d859d78
|
1910 1911 1912 1913 |
nordrand [X86] Disable the direct use of the RDRAND instruction even if it is supported by the processor. RDRAND is still available to user space applications. |
a99130449
|
1914 1915 |
noresume [SWSUSP] Disables resume and restores original swap space. |
1da177e4c
|
1916 1917 1918 1919 1920 |
no-scroll [VGA] Disables scrollback. This is required for the Braillex ib80-piezo Braille reader made by F.H. Papenmeier (Germany). nosbagart [IA-64] |
cd4f0ef7c
|
1921 |
nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support. |
4f8865112
|
1922 |
|
61ec7567d
|
1923 1924 |
nosmp [SMP] Tells an SMP kernel to act as a UP kernel, and disable the IO APIC. legacy for "maxcpus=0". |
1da177e4c
|
1925 |
|
97842216b
|
1926 |
nosoftlockup [KNL] Disable the soft-lockup detector. |
1da177e4c
|
1927 |
nosync [HW,M68K] Disables sync negotiation for all devices. |
cd4f0ef7c
|
1928 |
notsc [BUGS=X86-32] Disable Time Stamp Counter |
1da177e4c
|
1929 1930 |
nousb [USB] Disable the USB subsystem |
551423748
|
1931 |
nowatchdog [KNL] Disable the lockup detector (NMI watchdog). |
58687acba
|
1932 |
|
1da177e4c
|
1933 |
nowb [ARM] |
a99130449
|
1934 |
|
2b2fd87a6
|
1935 |
nox2apic [X86-64,APIC] Do not enable x2APIC mode. |
f78cff48c
|
1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 |
cpu0_hotplug [X86] Turn on CPU0 hotplug feature when CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off. Some features depend on CPU0. Known dependencies are: 1. Resume from suspend/hibernate depends on CPU0. Suspend/hibernate will fail if CPU0 is offline and you need to online CPU0 before suspend/hibernate. 2. PIC interrupts also depend on CPU0. CPU0 can't be removed if a PIC interrupt is detected. It's said poweroff/reboot may depend on CPU0 on some machines although I haven't seen such issues so far after CPU0 is offline on a few tested machines. If the dependencies are under your control, you can turn on cpu0_hotplug. |
162902466
|
1949 |
nptcg= [IA-64] Override max number of concurrent global TLB |
a6c75b86c
|
1950 1951 |
purges which is reported from either PAL_VM_SUMMARY or SAL PALO. |
2b633e3fa
|
1952 1953 1954 1955 1956 |
nr_cpus= [SMP] Maximum number of processors that an SMP kernel could support. nr_cpus=n : n >= 1 limits the kernel to supporting 'n' processors. Later in runtime you can not use hotplug cpu feature to put more cpu back to online. just like you compile the kernel NR_CPUS=n |
0cb55ad2a
|
1957 |
nr_uarts= [SERIAL] maximum number of UARTs to be registered. |
1a687c2e9
|
1958 1959 |
numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing. Allowed values are enable and disable |
f0c0b2b80
|
1960 1961 1962 1963 |
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. one of ['zone', 'node', 'default'] can be specified This can be set from sysctl after boot. See Documentation/sysctl/vm.txt for details. |
7c4be253d
|
1964 1965 1966 |
ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. See Documentation/debugging-via-ohci1394.txt for more info. |
3ef0e1f8c
|
1967 1968 1969 1970 1971 1972 |
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands Rather than timing out after 20 ms if an EC command is not properly ACKed, override the length of the timeout. We have interrupts disabled while waiting for the ACK, so if this is set too high interrupts *may* be lost! |
15ac7afe5
|
1973 1974 1975 1976 |
omap_mux= [OMAP] Override bootloader pin multiplexing. Format: <mux_mode0.mode_name=value>... For example, to override I2C bus2: omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100 |
1da177e4c
|
1977 1978 |
oprofile.timer= [HW] Use timer interrupt instead of performance counters |
7e4e0bd50
|
1979 1980 1981 |
oprofile.cpu_type= Force an oprofile cpu type This might be useful if you have an older oprofile userland or if you want common events. |
8d7ff4f2a
|
1982 1983 |
Format: { arch_perfmon } arch_perfmon: [X86] Force use of architectural |
7e4e0bd50
|
1984 1985 |
perfmon on Intel CPUs instead of the CPU specific event set. |
159a80b21
|
1986 1987 1988 |
timer: [X86] Force use of architectural NMI timer mode (see also oprofile.timer for generic hr timer mode) |
dd3c4670d
|
1989 1990 |
[s390] Force legacy basic mode sampling (report cpu_type "timer") |
1dcdb5a9e
|
1991 |
|
44a4dcf75
|
1992 1993 1994 |
oops=panic Always panic on oopses. Default is to just kill the process, but there is a small probability of deadlocking the machine. |
d404ab0a1
|
1995 1996 |
This will also cause panics on machine check exceptions. Useful together with panic=30 to trigger a reboot. |
bcfde3347
|
1997 1998 |
OSS [HW,OSS] See Documentation/sound/oss/oss-parameters.txt |
44a4dcf75
|
1999 |
panic= [KNL] Kernel behaviour on panic: delay <timeout> |
4302fbc8e
|
2000 2001 2002 |
timeout > 0: seconds before rebooting timeout = 0: wait forever timeout < 0: reboot immediately |
1da177e4c
|
2003 2004 2005 2006 2007 2008 2009 |
Format: <timeout> parkbd.port= [HW] Parallel port number the keyboard adapter is connected to, default is 0. Format: <parport#> parkbd.mode= [HW] Parallel port keyboard adapter mode of operation, 0 for XT, 1 for AT (default is AT). |
a99130449
|
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 |
Format: <mode> parport= [HW,PPT] Specify parallel ports. 0 disables. Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] } Use 'auto' to force the driver to use any IRQ/DMA settings detected (the default is to ignore detected IRQ/DMA settings because of possible conflicts). You can specify the base address, IRQ, and DMA settings; IRQ and DMA should be numbers, or 'auto' (for using detected settings on that particular port), or 'nofifo' (to avoid using a FIFO even if it is detected). Parallel ports are assigned in the order they are specified on the command line, starting with parport0. parport_init_mode= [HW,PPT] Configure VIA parallel port to operate in a specific mode. This is necessary on Pegasos computer where firmware has no options for setting up parallel port mode and sets it to spp. Currently this function knows 686a and 8231 chips. |
1da177e4c
|
2032 |
Format: [spp|ps2|epp|ecp|ecpepp] |
dd287796d
|
2033 2034 2035 2036 |
pause_on_oops= Halt all CPUs after the first oops has been printed for the specified number of seconds. This is to be used if your oopses keep scrolling off the screen. |
1da177e4c
|
2037 2038 2039 2040 |
pcbit= [HW,ISDN] pcd. [PARIDE] See header of drivers/block/paride/pcd.c. |
31c00fc15
|
2041 |
See also Documentation/blockdev/paride.txt. |
1da177e4c
|
2042 |
|
a99130449
|
2043 |
pci=option[,option...] [PCI] various PCI subsystem options: |
1cc0ca26c
|
2044 2045 |
earlydump [X86] dump PCI config space before the kernel changes anything |
c01156061
|
2046 |
off [X86] don't probe for the PCI bus |
cd4f0ef7c
|
2047 |
bios [X86-32] force use of PCI BIOS, don't access |
a99130449
|
2048 2049 |
the hardware directly. Use this if your machine has a non-standard PCI host bridge. |
cd4f0ef7c
|
2050 |
nobios [X86-32] disallow use of PCI BIOS, only direct |
a99130449
|
2051 2052 2053 |
hardware access methods are allowed. Use this if you experience crashes upon bootup and you suspect they are caused by the BIOS. |
c01156061
|
2054 |
conf1 [X86] Force use of PCI Configuration |
a99130449
|
2055 |
Mechanism 1. |
c01156061
|
2056 |
conf2 [X86] Force use of PCI Configuration |
a99130449
|
2057 |
Mechanism 2. |
7f7857636
|
2058 2059 2060 |
noaer [PCIE] If the PCIEAER kernel config parameter is enabled, this kernel boot option can be used to disable the use of PCIE advanced error reporting. |
32a2eea79
|
2061 2062 |
nodomains [PCI] Disable support for multiple PCI root domains (aka PCI segments, in ACPI-speak). |
6cececfce
|
2063 |
nommconf [X86] Disable use of MMCONFIG for PCI |
61be6d660
|
2064 |
Configuration |
129830773
|
2065 2066 2067 |
check_enable_amd_mmconf [X86] check for and enable properly configured MMIO access to PCI config space on AMD family 10h CPU |
309e57df7
|
2068 2069 2070 |
nomsi [MSI] If the PCI_MSI kernel config parameter is enabled, this kernel boot option can be used to disable the use of MSI interrupts system-wide. |
a9322f648
|
2071 2072 2073 |
noioapicquirk [APIC] Disable all boot interrupt quirks. Safety option to keep boot IRQs enabled. This should never be necessary. |
9197979b5
|
2074 2075 2076 2077 |
ioapicreroute [APIC] Enable rerouting of boot IRQs to the primary IO-APIC for bridges that cannot disable boot IRQs. This fixes a source of spurious IRQs when the system masks IRQs. |
41b9eb264
|
2078 2079 2080 2081 |
noioapicreroute [APIC] Disable workaround that uses the boot IRQ equivalent of an IRQ that connects to a chipset where boot IRQs cannot be disabled. The opposite of ioapicreroute. |
cd4f0ef7c
|
2082 |
biosirq [X86-32] Use PCI BIOS calls to get the interrupt |
a99130449
|
2083 2084 2085 2086 2087 2088 2089 |
routing table. These calls are known to be buggy on several machines and they hang the machine when used, but on other computers it's the only way to get the interrupt routing table. Try this option if the kernel is unable to allocate IRQs or discover secondary PCI buses on your motherboard. |
c01156061
|
2090 |
rom [X86] Assign address space to expansion ROMs. |
a99130449
|
2091 2092 2093 |
Use with caution as certain devices share address decoders between ROMs and other resources. |
c01156061
|
2094 |
norom [X86] Do not assign address space to |
bb71ad880
|
2095 2096 |
expansion ROMs that do not already have BIOS assigned address ranges. |
7bd1c365f
|
2097 2098 |
nobar [X86] Do not assign address space to the BARs that weren't assigned by the BIOS. |
c01156061
|
2099 |
irqmask=0xMMMM [X86] Set a bit mask of IRQs allowed to be |
a99130449
|
2100 2101 2102 |
assigned automatically to PCI devices. You can make the kernel exclude IRQs of your ISA cards this way. |
c01156061
|
2103 |
pirqaddr=0xAAAAA [X86] Specify the physical address |
a99130449
|
2104 2105 2106 |
of the PIRQ table (normally generated by the BIOS) if it is outside the F0000h-100000h range. |
c01156061
|
2107 |
lastbus=N [X86] Scan all buses thru bus #N. Can be |
a99130449
|
2108 2109 2110 |
useful if the kernel is unable to find your secondary buses and you want to tell it explicitly which ones they are. |
c01156061
|
2111 |
assign-busses [X86] Always assign all PCI bus |
a99130449
|
2112 2113 |
numbers ourselves, overriding whatever the firmware may have done. |
c01156061
|
2114 |
usepirqmask [X86] Honor the possible IRQ mask stored |
a99130449
|
2115 2116 2117 2118 2119 |
in the BIOS $PIR table. This is needed on some systems with broken BIOSes, notably some HP Pavilion N5400 and Omnibook XE3 notebooks. This will have no effect if ACPI IRQ routing is enabled. |
c01156061
|
2120 |
noacpi [X86] Do not use ACPI for IRQ routing |
a99130449
|
2121 |
or for PCI scanning. |
7bc5e3f2b
|
2122 2123 2124 2125 2126 2127 |
use_crs [X86] Use PCI host bridge window information from ACPI. On BIOSes from 2008 or later, this 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. |
a99130449
|
2128 2129 2130 2131 |
routeirq Do IRQ routing for all PCI devices. This is normally done in pci_enable_device(), so this option is a temporary workaround for broken drivers that don't call it. |
13a6ddb08
|
2132 2133 |
skip_isa_align [X86] do not align io start addr, so can handle more pci cards |
a99130449
|
2134 2135 2136 2137 2138 |
firmware [ARM] Do not re-enumerate the bus but instead just use the configuration from the bootloader. This is currently used on IXP2000 systems where the bus has to be configured a certain way for adjunct CPUs. |
0637a70a5
|
2139 2140 2141 2142 2143 |
noearly [X86] Don't do any early type 1 scanning. This might help on some broken boards which machine check when some devices' config space is read. But various workarounds are disabled and some IOMMU drivers will not work. |
6b4b78fed
|
2144 2145 2146 2147 |
bfsort Sort PCI devices into breadth-first order. This sorting is done to get a device order compatible with older (<= 2.4) kernels. nobfsort Don't sort PCI devices into breadth-first order. |
fa2387124
|
2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 |
pcie_bus_tune_off Disable PCIe MPS (Max Payload Size) tuning and use the BIOS-configured MPS defaults. pcie_bus_safe Set every device's MPS to the largest value supported by all devices below the root complex. pcie_bus_perf Set device MPS to the largest allowable MPS based on its parent bus. Also set MRRS (Max Read Request Size) to the largest supported value (no larger than the MPS that the device or bus can support) for best performance. pcie_bus_peer2peer Set every device's MPS to 128B, which every device is guaranteed to support. This configuration allows peer-to-peer DMA between any pair of devices, possibly at the cost of reduced performance. This also guarantees that hot-added devices will work. |
4516a618a
|
2163 2164 2165 2166 2167 2168 |
cbiosize=nn[KMG] The fixed amount of bus space which is reserved for the CardBus bridge's IO window. The default value is 256 bytes. cbmemsize=nn[KMG] The fixed amount of bus space which is reserved for the CardBus bridge's memory window. The default value is 64 megabytes. |
32a9a682b
|
2169 2170 2171 2172 2173 2174 2175 2176 2177 |
resource_alignment= Format: [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...] Specifies alignment and device to reassign aligned memory resources. If <order of align> is not specified, PAGE_SIZE is used as alignment. PCI-PCI bridge can be specified, if resource windows need to be expanded. |
43c164088
|
2178 2179 2180 2181 2182 2183 |
ecrc= Enable/disable PCIe ECRC (transaction layer end-to-end CRC checking). bios: Use BIOS/firmware settings. This is the the default. off: Turn ECRC off on: Turn ECRC on. |
8c8803c59
|
2184 2185 2186 2187 2188 2189 |
hpiosize=nn[KMG] The fixed amount of bus space which is reserved for hotplug bridge's IO window. Default size is 256 bytes. hpmemsize=nn[KMG] The fixed amount of bus space which is reserved for hotplug bridge's memory window. Default size is 2 megabytes. |
b55438fdd
|
2190 2191 2192 2193 2194 2195 2196 |
realloc= Enable/disable reallocating PCI bridge resources if allocations done by BIOS are too small to accommodate resources required by all child devices. off: Turn realloc off on: Turn realloc on realloc same as realloc=on |
6748dcc26
|
2197 |
noari do not use PCIe ARI. |
284f5f9db
|
2198 2199 2200 |
pcie_scan_all Scan all possible PCIe devices. Otherwise we only look for one device below a PCIe downstream port. |
6b4b78fed
|
2201 |
|
e5665a45f
|
2202 2203 2204 2205 2206 |
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. off Disable ASPM. force Enable ASPM even on devices that claim not to support it. WARNING: Forcing ASPM on may cause system lockups. |
7570a333d
|
2207 2208 2209 |
pcie_hp= [PCIE] PCI Express Hotplug driver options: nomsi Do not use MSI for PCI Express Native Hotplug (this makes all PCIe ports use INTx for hotplug services). |
79dd9182d
|
2210 |
pcie_ports= [PCIE] PCIe ports handling: |
28eb5f274
|
2211 2212 2213 2214 2215 |
auto Ask the BIOS whether or not to use native PCIe services associated with PCIe ports (PME, hot-plug, AER). Use them only if that is allowed by the BIOS. native Use native PCIe services associated with PCIe ports unconditionally. |
79dd9182d
|
2216 2217 |
compat Treat PCIe ports as PCI-to-PCI bridges, disable the PCIe ports driver. |
c7f486567
|
2218 |
pcie_pme= [PCIE,PM] Native PCIe PME signaling options: |
c39fae141
|
2219 |
nomsi Do not use MSI for native PCIe PME signaling (this makes |
28eb5f274
|
2220 |
all PCIe root ports use INTx for all services). |
c7f486567
|
2221 |
|
1da177e4c
|
2222 2223 2224 |
pcmv= [HW,PCMCIA] BadgePAD 4 pd. [PARIDE] |
31c00fc15
|
2225 |
See Documentation/blockdev/paride.txt. |
1da177e4c
|
2226 2227 2228 2229 2230 |
pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at boot time. Format: { 0 | 1 } See arch/parisc/kernel/pdc_chassis.c |
f58dc01ba
|
2231 |
percpu_alloc= Select which percpu first chunk allocator to use. |
e933a73f4
|
2232 2233 2234 2235 2236 |
Currently supported values are "embed" and "page". Archs may support subset or none of the selections. See comments in mm/percpu.c for details on each allocator. This parameter is primarily for debugging and performance comparison. |
fa8a7094b
|
2237 |
|
1da177e4c
|
2238 |
pf. [PARIDE] |
31c00fc15
|
2239 |
See Documentation/blockdev/paride.txt. |
1da177e4c
|
2240 2241 |
pg. [PARIDE] |
31c00fc15
|
2242 |
See Documentation/blockdev/paride.txt. |
1da177e4c
|
2243 2244 |
pirq= [SMP,APIC] Manual mp-table setup |
71cced6eb
|
2245 |
See Documentation/x86/i386/IO-APIC.txt. |
1da177e4c
|
2246 2247 2248 2249 |
plip= [PPT,NET] Parallel port network link Format: { parport<nr> | timid | 0 } See also Documentation/parport.txt. |
162902466
|
2250 |
pmtmr= [X86] Manual setup of pmtmr I/O Port. |
de32a2434
|
2251 2252 |
Override pmtimer IOPort with a hex value. e.g. pmtmr=0x508 |
96242116d
|
2253 2254 2255 2256 2257 2258 |
pnp.debug=1 [PNP] Enable PNP debug messages (depends on the CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time via /sys/module/pnp/parameters/debug. We always show current resource usage; turning this on also shows possible settings and some assignment information. |
97ef062bb
|
2259 |
|
1da177e4c
|
2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 |
pnpacpi= [ACPI] { off } pnpbios= [ISAPNP] { on | off | curr | res | no-curr | no-res } pnp_reserve_irq= [ISAPNP] Exclude IRQs for the autoconfiguration pnp_reserve_dma= [ISAPNP] Exclude DMAs for the autoconfiguration pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration |
a99130449
|
2273 |
Ranges are in pairs (I/O port base and size). |
1da177e4c
|
2274 2275 |
pnp_reserve_mem= |
a99130449
|
2276 2277 |
[ISAPNP] Exclude memory regions for the autoconfiguration. |
1da177e4c
|
2278 |
Ranges are in pairs (memory base and size). |
4af94f390
|
2279 2280 2281 2282 2283 |
ports= [IP_VS_FTP] IPVS ftp helper module Default is 21. Up to 8 (IP_VS_APP_MAX_PORTS) ports may be specified. Format: <port>,<port>.... |
45807a1df
|
2284 2285 |
print-fatal-signals= [KNL] debug: print fatal signals |
f84d49b21
|
2286 2287 2288 2289 2290 2291 2292 2293 |
If enabled, warn about various signal handling related application anomalies: too many signals, too many POSIX.1 timers, fatal signals causing a coredump - etc. If you hit the warning due to signal overflow, you might want to try "ulimit -i unlimited". |
45807a1df
|
2294 |
default: off. |
c22ab3329
|
2295 2296 2297 2298 2299 |
printk.always_kmsg_dump= Trigger kmsg_dump for cases other than kernel oops or panics Format: <bool> (1/Y/y=enable, 0/N/n=disable) default: disabled |
e84845c4b
|
2300 2301 |
printk.time= Show timing data prefixed to each printk message line Format: <bool> (1/Y/y=enable, 0/N/n=disable) |
0cb55ad2a
|
2302 2303 2304 2305 2306 2307 2308 |
processor.max_cstate= [HW,ACPI] Limit processor to maximum C-state max_cstate=9 overrides any DMI blacklist limit. processor.nocst [HW,ACPI] Ignore the _CST method to determine C-states, instead using the legacy FADT method |
1da177e4c
|
2309 |
profile= [KNL] Enable kernel profiling via /proc/profile |
a99130449
|
2310 2311 2312 2313 |
Format: [schedule,]<number> Param: "schedule" - profile schedule points. Param: <number> - step/bucket size as a power of 2 for statistical time based profiling. |
b3da2a73f
|
2314 2315 |
Param: "sleep" - profile D-state sleeping (millisecs). Requires CONFIG_SCHEDSTATS |
c0fe2e696
|
2316 |
Param: "kvm" - profile VM exits. |
1da177e4c
|
2317 |
|
1da177e4c
|
2318 2319 |
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk before loading. |
31c00fc15
|
2320 |
See Documentation/blockdev/ramdisk.txt. |
1da177e4c
|
2321 |
|
a99130449
|
2322 2323 |
psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to probe for; one of (bare|imps|exps|lifebook|any). |
1da177e4c
|
2324 2325 |
psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports per second. |
a99130449
|
2326 2327 |
psmouse.resetafter= [HW,MOUSE] Try to reset the device after so many bad packets |
1da177e4c
|
2328 2329 2330 2331 |
(0 = never). psmouse.resolution= [HW,MOUSE] Set desired mouse resolution, in dpi. psmouse.smartscroll= |
a99130449
|
2332 |
[HW,MOUSE] Controls Logitech smartscroll autorepeat. |
1da177e4c
|
2333 |
0 = disabled, 1 = enabled (default). |
dee28e72b
|
2334 |
pstore.backend= Specify the name of the pstore backend to use |
1da177e4c
|
2335 |
pt. [PARIDE] |
31c00fc15
|
2336 |
See Documentation/blockdev/paride.txt. |
1da177e4c
|
2337 |
|
dc8c85871
|
2338 2339 2340 |
pty.legacy_count= [KNL] Number of legacy pty's. Overwrites compiled-in default number. |
7d2c502f1
|
2341 |
quiet [KNL] Disable most log messages |
a99130449
|
2342 |
|
1da177e4c
|
2343 2344 2345 2346 |
r128= [HW,DRM] raid= [HW,RAID] See Documentation/md.txt. |
a99130449
|
2347 |
ramdisk_blocksize= [RAM] |
31c00fc15
|
2348 |
See Documentation/blockdev/ramdisk.txt. |
a99130449
|
2349 |
|
1da177e4c
|
2350 |
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
31c00fc15
|
2351 |
See Documentation/blockdev/ramdisk.txt. |
1da177e4c
|
2352 |
|
3fbfbf7a3
|
2353 2354 2355 2356 |
rcu_nocbs= [KNL,BOOT] In kernels built with CONFIG_RCU_NOCB_CPU=y, set the specified list of CPUs to be no-callback CPUs. Invocation of these CPUs' RCU callbacks will |
a48898585
|
2357 2358 2359 2360 |
be offloaded to "rcuox/N" kthreads created for that purpose, where "x" is "b" for RCU-bh, "p" for RCU-preempt, and "s" for RCU-sched, and "N" is the CPU number. This reduces OS jitter on the |
3fbfbf7a3
|
2361 |
offloaded CPUs, which can be useful for HPC and |
a48898585
|
2362 |
|
3fbfbf7a3
|
2363 2364 |
real-time workloads. It can also improve energy efficiency for asymmetric multiprocessors. |
1b0048a44
|
2365 |
rcu_nocb_poll [KNL,BOOT] |
3fbfbf7a3
|
2366 2367 2368 2369 2370 2371 2372 2373 2374 |
Rather than requiring that offloaded CPUs (specified by rcu_nocbs= above) explicitly awaken the corresponding "rcuoN" kthreads, make these kthreads poll for callbacks. This improves the real-time response for the offloaded CPUs by relieving them of the need to wake up the corresponding kthread, but degrades energy efficiency by requiring that the kthreads periodically wake up to do the polling. |
dabb8aa96
|
2375 |
rcutree.blimit= [KNL,BOOT] |
24aaef8d7
|
2376 2377 |
Set maximum number of finished RCU callbacks to process in one batch. |
21a1ea9eb
|
2378 |
|
f885b7f2b
|
2379 2380 2381 2382 |
rcutree.fanout_leaf= [KNL,BOOT] Increase the number of CPUs assigned to each leaf rcu_node structure. Useful for very large systems. |
c0f4dfd4f
|
2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 |
rcutree.jiffies_till_first_fqs= [KNL,BOOT] Set delay from grace-period initialization to first attempt to force quiescent states. Units are jiffies, minimum value is zero, and maximum value is HZ. rcutree.jiffies_till_next_fqs= [KNL,BOOT] Set delay between subsequent attempts to force quiescent states. Units are jiffies, minimum value is one, and maximum value is HZ. |
dabb8aa96
|
2393 |
rcutree.qhimark= [KNL,BOOT] |
24aaef8d7
|
2394 |
Set threshold of queued |
21a1ea9eb
|
2395 |
RCU callbacks over which batch limiting is disabled. |
dabb8aa96
|
2396 |
rcutree.qlowmark= [KNL,BOOT] |
24aaef8d7
|
2397 2398 |
Set threshold of queued RCU callbacks below which batch limiting is re-enabled. |
21a1ea9eb
|
2399 |
|
dabb8aa96
|
2400 2401 2402 2403 2404 |
rcutree.rcu_cpu_stall_suppress= [KNL,BOOT] Suppress RCU CPU stall warning messages. rcutree.rcu_cpu_stall_timeout= [KNL,BOOT] Set timeout for RCU CPU stall warning messages. |
c0f4dfd4f
|
2405 2406 2407 |
rcutree.rcu_idle_gp_delay= [KNL,BOOT] Set wakeup interval for idle CPUs that have RCU callbacks (RCU_FAST_NO_HZ=y). |
d40011f60
|
2408 |
|
c0f4dfd4f
|
2409 2410 2411 2412 2413 |
rcutree.rcu_idle_lazy_gp_delay= [KNL,BOOT] Set wakeup interval for idle CPUs that have only "lazy" RCU callbacks (RCU_FAST_NO_HZ=y). Lazy RCU callbacks are those which RCU can prove do nothing more than free memory. |
d40011f60
|
2414 |
|
dabb8aa96
|
2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 |
rcutorture.fqs_duration= [KNL,BOOT] Set duration of force_quiescent_state bursts. rcutorture.fqs_holdoff= [KNL,BOOT] Set holdoff time within force_quiescent_state bursts. rcutorture.fqs_stutter= [KNL,BOOT] Set wait time between force_quiescent_state bursts. rcutorture.irqreader= [KNL,BOOT] Test RCU readers from irq handlers. rcutorture.n_barrier_cbs= [KNL,BOOT] Set callbacks/threads for rcu_barrier() testing. rcutorture.nfakewriters= [KNL,BOOT] Set number of concurrent RCU writers. These just stress RCU, they don't participate in the actual test, hence the "fake". rcutorture.nreaders= [KNL,BOOT] Set number of RCU readers. rcutorture.onoff_holdoff= [KNL,BOOT] Set time (s) after boot for CPU-hotplug testing. rcutorture.onoff_interval= [KNL,BOOT] Set time (s) between CPU-hotplug operations, or zero to disable CPU-hotplug testing. rcutorture.shuffle_interval= [KNL,BOOT] Set task-shuffle interval (s). Shuffling tasks allows some CPUs to go into dyntick-idle mode during the rcutorture test. rcutorture.shutdown_secs= [KNL,BOOT] Set time (s) after boot system shutdown. This is useful for hands-off automated testing. rcutorture.stall_cpu= [KNL,BOOT] Duration of CPU stall (s) to test RCU CPU stall warnings, zero to disable. rcutorture.stall_cpu_holdoff= [KNL,BOOT] Time to wait (s) after boot before inducing stall. rcutorture.stat_interval= [KNL,BOOT] Time (s) between statistics printk()s. rcutorture.stutter= [KNL,BOOT] Time (s) to stutter testing, for example, specifying five seconds causes the test to run for five seconds, wait for five seconds, and so on. This tests RCU's ability to transition abruptly to and from idle. rcutorture.test_boost= [KNL,BOOT] Test RCU priority boosting? 0=no, 1=maybe, 2=yes. "Maybe" means test if the RCU implementation under test support RCU priority boosting. rcutorture.test_boost_duration= [KNL,BOOT] Duration (s) of each individual boost test. rcutorture.test_boost_interval= [KNL,BOOT] Interval (s) between each boost test. rcutorture.test_no_idle_hz= [KNL,BOOT] Test RCU's dyntick-idle handling. See also the rcutorture.shuffle_interval parameter. rcutorture.torture_type= [KNL,BOOT] Specify the RCU implementation to test. rcutorture.verbose= [KNL,BOOT] Enable additional printk() statements. |
ffdfc4097
|
2490 2491 2492 2493 |
rdinit= [KNL] Format: <full_path> Run specified binary instead of /init from the ramdisk, used for early userspace startup. See initrd. |
1b3a5d02e
|
2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 |
reboot= [KNL] Format (x86 or x86_64): [w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \ [[,]s[mp]#### \ [[,]b[ios] | a[cpi] | k[bd] | t[riple] | e[fi] | p[ci]] \ [[,]f[orce] Where reboot_mode is one of warm (soft) or cold (hard) or gpio, reboot_type is one of bios, acpi, kbd, triple, efi, or pci, reboot_force is either force or not specified, reboot_cpu is s[mp]#### with #### being the processor to be used for rebooting. |
1da177e4c
|
2505 |
|
46b6d94eb
|
2506 2507 |
relax_domain_level= [KNL, SMP] Set scheduler's default relax_domain_level. |
21acb9caa
|
2508 |
See Documentation/cgroups/cpusets.txt. |
46b6d94eb
|
2509 |
|
1da177e4c
|
2510 |
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area |
cd4f0ef7c
|
2511 |
reservetop= [X86-32] |
461a9afff
|
2512 2513 2514 |
Format: nn[KMG] Reserves a hole at the top of the kernel virtual address space. |
9ea77bdb3
|
2515 2516 2517 2518 |
reservelow= [X86] Format: nn[K] Set the amount of memory to reserve for BIOS at the bottom of the address space. |
7e96287dd
|
2519 2520 |
reset_devices [KNL] Force drivers to reset the underlying device during initialization. |
a99130449
|
2521 2522 |
resume= [SWSUSP] Specify the partition device for software suspend |
2df83fa4b
|
2523 2524 |
Format: {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>} |
1da177e4c
|
2525 |
|
ecbd0da1e
|
2526 2527 2528 2529 2530 |
resume_offset= [SWSUSP] Specify the offset from the beginning of the partition given by "resume=" at which the swap header is located, in <PAGE_SIZE> units (needed only for swap files). See Documentation/power/swsusp-and-swap-files.txt |
f126f7334
|
2531 2532 |
resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to read the resume files |
6f8d7022a
|
2533 2534 2535 |
resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up. Useful for devices that are detected asynchronously (e.g. USB and MMC devices). |
f996fc967
|
2536 2537 2538 2539 |
hibernate= [HIBERNATION] noresume Don't check if there's a hibernation image present during boot. nocompress Don't compress/decompress hibernation images. |
0a7b35cb1
|
2540 |
retain_initrd [RAM] Keep initrd memory after extraction |
1da177e4c
|
2541 2542 2543 2544 2545 2546 2547 2548 2549 |
rhash_entries= [KNL,NET] Set number of hash buckets for route cache riscom8= [HW,SERIAL] Format: <io_board1>[,<io_board2>[,...<io_boardN>]] ro [KNL] Mount root device read-only on boot root= [KNL] Root filesystem |
f2d34fd94
|
2550 |
See name_to_dev_t comment in init/do_mounts.c. |
1da177e4c
|
2551 2552 2553 2554 2555 2556 2557 |
rootdelay= [KNL] Delay (in seconds) to pause before attempting to mount the root filesystem rootflags= [KNL] Set root filesystem mount option string rootfstype= [KNL] Set root filesystem type |
cc1ed7542
|
2558 2559 2560 |
rootwait [KNL] Wait (indefinitely) for root device to show up. Useful for devices that are detected asynchronously (e.g. USB and MMC devices). |
5c71d6181
|
2561 2562 2563 2564 |
rproc_mem=nn[KMG][@address] [KNL,ARM,CMA] Remoteproc physical memory block. Memory area to be used by remote processor image, managed by CMA. |
1da177e4c
|
2565 2566 2567 2568 2569 2570 |
rw [KNL] Mount root device read-write on boot S [KNL] Run init in single mode sa1100ir [NET] See drivers/net/irda/sa1100_ir.c. |
1da177e4c
|
2571 |
sbni= [NET] Granch SBNI12 leased line adapter |
a99130449
|
2572 |
|
f6630114d
|
2573 |
sched_debug [KNL] Enables verbose scheduler debug messages. |
5307c9556
|
2574 2575 2576 2577 2578 2579 2580 2581 |
skew_tick= [KNL] Offset the periodic timer tick per cpu to mitigate xtime_lock contention on larger systems, and/or RCU lock contention on all systems with CONFIG_MAXSMP set. Format: { "0" | "1" } 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1" 1 -- enable. Note: increases power consumption, thus should only be enabled if running jitter sensitive (HPC/RT) workloads. |
0cb55ad2a
|
2582 2583 2584 2585 2586 2587 2588 |
security= [SECURITY] Choose a security module to enable at boot. If this boot parameter is not specified, only the first security module asking for security registration will be loaded. An invalid security module name will be treated as if no module has been chosen. selinux= [SELINUX] Disable or enable SELinux at boot time. |
1da177e4c
|
2589 2590 2591 2592 2593 2594 2595 |
Format: { "0" | "1" } See security/selinux/Kconfig help text. 0 -- disable. 1 -- enable. Default value is set via kernel config option. If enabled at boot time, /selinux/disable can be used later to disable prior to initial policy load. |
c1c124e91
|
2596 2597 2598 2599 2600 2601 |
apparmor= [APPARMOR] Disable or enable AppArmor at boot time Format: { "0" | "1" } See security/apparmor/Kconfig help text 0 -- disable. 1 -- enable. Default value is set via kernel config option. |
cd4f0ef7c
|
2602 |
serialnumber [BUGS=X86-32] |
1da177e4c
|
2603 |
|
1da177e4c
|
2604 2605 |
shapers= [NET] Maximal number of shapers. |
a99130449
|
2606 |
|
b05f78f5c
|
2607 2608 2609 2610 2611 |
show_msr= [x86] show boot-time MSR settings Format: { <integer> } Show boot-time (BIOS-initialized) MSR settings. The parameter means the number of CPUs to show, for example 1 means boot CPU only. |
1da177e4c
|
2612 2613 |
simeth= [IA-64] simscsi= |
a99130449
|
2614 |
|
1da177e4c
|
2615 |
slram= [HW,MTD] |
3df1cccdf
|
2616 2617 2618 2619 2620 |
slab_max_order= [MM, SLAB] Determines the maximum allowed order for slabs. A high setting may cause OOMs due to memory fragmentation. Defaults to 1 for systems with more than 32MB of RAM, 0 otherwise. |
f0630fff5
|
2621 2622 2623 2624 2625 2626 2627 |
slub_debug[=options[,slabs]] [MM, SLUB] Enabling slub_debug allows one to determine the culprit if slab objects become corrupted. Enabling 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. |
c1aee215d
|
2628 2629 |
slub_max_order= [MM, SLUB] |
f0630fff5
|
2630 2631 2632 2633 |
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. |
c1aee215d
|
2634 2635 |
slub_min_objects= [MM, SLUB] |
f0630fff5
|
2636 2637 2638 2639 2640 2641 |
The minimum number of objects per slab. SLUB will increase the slab order up to slub_max_order to generate a sufficiently large slab able to contain 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. |
c1aee215d
|
2642 2643 2644 |
For more information see Documentation/vm/slub.txt. slub_min_order= [MM, SLUB] |
24775d652
|
2645 |
Determines the minimum page order for slabs. Must be |
f0630fff5
|
2646 |
lower than slub_max_order. |
c1aee215d
|
2647 2648 2649 |
For more information see Documentation/vm/slub.txt. slub_nomerge [MM, SLUB] |
f0630fff5
|
2650 |
Disable merging of slabs with similar size. May be |
c1aee215d
|
2651 |
necessary if there is some reason to distinguish |
f0630fff5
|
2652 2653 |
allocs to different slabs. Debug options disable merging on their own. |
c1aee215d
|
2654 |
For more information see Documentation/vm/slub.txt. |
1da177e4c
|
2655 2656 |
smart2= [HW] Format: <io1>[,<io2>[,...,<io8>]] |
d0d4f69bb
|
2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 |
smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port smsc-ircc2.ircc_sir= [HW] SIR base I/O port smsc-ircc2.ircc_fir= [HW] FIR base I/O port smsc-ircc2.ircc_irq= [HW] IRQ line smsc-ircc2.ircc_dma= [HW] DMA channel smsc-ircc2.ircc_transceiver= [HW] Transceiver type: 0: Toshiba Satellite 1800 (GP data pin select) 1: Fast pin select (default) 2: ATC IRMode |
9c44bc03f
|
2667 2668 |
softlockup_panic= [KNL] Should the soft-lockup detector generate panics. |
44a4dcf75
|
2669 |
Format: <integer> |
9c44bc03f
|
2670 |
|
1da177e4c
|
2671 |
sonypi.*= [HW] Sony Programmable I/O Control Device driver |
395cf9691
|
2672 |
See Documentation/laptops/sonypi.txt |
1da177e4c
|
2673 2674 |
specialix= [HW,SERIAL] Specialix multi-serial port adapter |
31c00fc15
|
2675 |
See Documentation/serial/specialix.txt. |
1da177e4c
|
2676 2677 2678 2679 2680 |
spia_io_base= [HW,MTD] spia_fio_base= spia_pedr= spia_peddr= |
f38f1d2aa
|
2681 2682 |
stacktrace [FTRACE] Enabled the stack tracer on boot up. |
762e12078
|
2683 2684 2685 2686 2687 2688 2689 |
stacktrace_filter=[function-list] [FTRACE] Limit the functions that the stack tracer will trace at boot up. function-list is a comma separated list of functions. This list can be changed at run time by the stack_trace_filter file in the debugfs tracing directory. Note, this enables stack tracing and the stacktrace above is not needed. |
1da177e4c
|
2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 |
sti= [PARISC,HW] Format: <num> Set the STI (builtin display/keyboard on the HP-PARISC machines) console (graphic card) which should be used as the initial boot-console. See also comment in drivers/video/console/sticore.c. sti_font= [HW] See comment in drivers/video/console/sticore.c. stifb= [HW] Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] |
cbf110712
|
2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 |
sunrpc.min_resvport= sunrpc.max_resvport= [NFS,SUNRPC] SunRPC servers often require that client requests originate from a privileged port (i.e. a port in the range 0 < portnr < 1024). An administrator who wishes to reserve some of these ports for other uses may adjust the range that the kernel's sunrpc client considers to be privileged using these two parameters to set the minimum and maximum port values. |
42a7fc4a6
|
2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 |
sunrpc.pool_mode= [NFS] Control how the NFS server code allocates CPUs to service thread pools. Depending on how many NICs you have and where their interrupts are bound, this option will affect which CPUs will do NFS serving. Note: this parameter cannot be changed while the NFS server is running. auto the server chooses an appropriate mode automatically using heuristics global a single global pool contains all CPUs percpu one pool for each CPU pernode one pool for each NUMA node (equivalent to global on non-NUMA machines) |
cbf110712
|
2728 2729 2730 2731 2732 2733 2734 2735 |
sunrpc.tcp_slot_table_entries= sunrpc.udp_slot_table_entries= [NFS,SUNRPC] Sets the upper limit on the number of simultaneous RPC calls that can be sent from the client to a server. Increasing these values may allow you to improve throughput, but will also increase the amount of memory reserved for use by the client. |
07555ac14
|
2736 |
swapaccount=[0|1] |
a42c390cf
|
2737 2738 2739 |
[KNL] Enable accounting of swap in memory resource controller if no parameter or 1 is given or disable it if 0 is given (See Documentation/cgroups/memory.txt) |
1da177e4c
|
2740 |
swiotlb= [IA-64] Number of I/O TLB slabs |
a99130449
|
2741 |
|
1da177e4c
|
2742 |
switches= [HW,M68k] |
e52eec13c
|
2743 2744 2745 2746 2747 2748 2749 2750 |
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. |
5d6f647fc
|
2751 2752 2753 2754 2755 |
sysrq_always_enabled [KNL] Ignore sysrq setting - this boot parameter will neutralize any effect of /proc/sys/kernel/sysrq. Useful for debugging. |
1da177e4c
|
2756 |
tdfx= [HW,DRM] |
77437fd4e
|
2757 2758 2759 2760 2761 |
test_suspend= [SUSPEND] Specify "mem" (for Suspend-to-RAM) or "standby" (for standby suspend) as the system sleep state to briefly enter during system startup. The system is woken from this state using a wakeup-capable RTC alarm. |
1da177e4c
|
2762 2763 |
thash_entries= [KNL,NET] Set number of hash buckets for TCP connection |
f8707ec96
|
2764 2765 2766 |
thermal.act= [HW,ACPI] -1: disable all active trip points in all thermal zones <degrees C>: override all lowest active trip points |
c52a7419a
|
2767 2768 |
thermal.crt= [HW,ACPI] -1: disable all critical trip points in all thermal zones |
22a94d79a
|
2769 |
<degrees C>: override all critical trip points |
c52a7419a
|
2770 |
|
f54871456
|
2771 2772 2773 |
thermal.nocrt= [HW,ACPI] Set to disable actions on ACPI thermal zone critical and hot trip points. |
72b33ef8b
|
2774 2775 |
thermal.off= [HW,ACPI] 1: disable ACPI thermal control |
a70cdc520
|
2776 2777 |
thermal.psv= [HW,ACPI] -1: disable all passive trip points |
ada9cfdd1
|
2778 2779 |
<degrees C>: override all passive trip points to this value |
a70cdc520
|
2780 |
|
730ff34de
|
2781 2782 2783 2784 |
thermal.tzp= [HW,ACPI] Specify global default ACPI thermal zone polling rate <deci-seconds>: poll all this frequency 0: no polling (default) |
8d32a307e
|
2785 2786 |
threadirqs [KNL] Force threading of all interrupt handlers except those |
24775d652
|
2787 |
marked explicitly IRQF_NO_THREAD. |
8d32a307e
|
2788 |
|
2ca62b044
|
2789 2790 2791 2792 2793 2794 2795 2796 2797 |
tmem [KNL,XEN] Enable the Transcendent memory driver if built-in. tmem.cleancache=0|1 [KNL, XEN] Default is on (1). Disable the usage of the cleancache API to send anonymous pages to the hypervisor. tmem.frontswap=0|1 [KNL, XEN] Default is on (1). Disable the usage of the frontswap |
37d46e152
|
2798 2799 |
API to send swap pages to the hypervisor. If disabled the selfballooning and selfshrinking are force disabled. |
2ca62b044
|
2800 2801 2802 2803 2804 2805 2806 2807 2808 |
tmem.selfballooning=0|1 [KNL, XEN] Default is on (1). Disable the driving of swap pages to the hypervisor. tmem.selfshrinking=0|1 [KNL, XEN] Default is on (1). Partial swapoff that immediately transfers pages from Xen hypervisor back to the kernel based on different criteria. |
2b1a61f0a
|
2809 2810 2811 |
topology= [S390] Format: {off | on} Specify if the kernel should make use of the cpu |
f65e51d74
|
2812 2813 |
topology information if the hardware supports this. The scheduler will make use of this information and |
2b1a61f0a
|
2814 |
e.g. base its process migration decisions on it. |
c9af3fa9e
|
2815 |
Default is on. |
2b1a61f0a
|
2816 |
|
1da177e4c
|
2817 |
tp720= [HW,PS2] |
225a9be24
|
2818 2819 2820 2821 2822 2823 2824 2825 |
tpm_suspend_pcr=[HW,TPM] Format: integer pcr id Specify that at suspend time, the tpm driver should extend the specified pcr with zeros, as a workaround for some chips which fail to flush the last written pcr on TPM_SaveState. This will guarantee that all the other pcrs are saved. |
9d612beff
|
2826 2827 |
trace_buf_size=nn[KMG] [FTRACE] will set tracing buffer size. |
631595fbf
|
2828 |
|
020e5f85c
|
2829 2830 2831 2832 |
trace_event=[event-list] [FTRACE] Set and start specified trace events in order to facilitate early boot debugging. See also Documentation/trace/events.txt |
7bcfaf54f
|
2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 |
trace_options=[option-list] [FTRACE] Enable or disable tracer options at boot. The option-list is a comma delimited list of options that can be enabled or disabled just as if you were to echo the option name into /sys/kernel/debug/tracing/trace_options For example, to enable stacktrace option (to dump the stack trace of each event), add to the command line: trace_options=stacktrace See also Documentation/trace/ftrace.txt "trace options" section. |
de7edd314
|
2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 |
traceoff_on_warning [FTRACE] enable this option to disable tracing when a warning is hit. This turns off "tracing_on". Tracing can be enabled again by echoing '1' into the "tracing_on" file located in /sys/kernel/debug/tracing/ This option is useful, as it disables the trace before the WARNING dump is called, which prevents the trace to be filled with content caused by the warning output. This option can also be set at run time via the sysctl option: kernel/traceoff_on_warning |
fcf4d8212
|
2860 2861 2862 2863 2864 2865 |
transparent_hugepage= [KNL] 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. |
d3b8f889a
|
2866 |
tsc= Disable clocksource stability checks for TSC. |
395628ef4
|
2867 2868 |
Format: <string> [x86] reliable: mark tsc clocksource as reliable, this |
d3b8f889a
|
2869 2870 2871 2872 |
disables clocksource verification at runtime, as well as the stability checks done at bootup. Used to enable high-resolution timer mode on older hardware, and in virtualized environment. |
e82b8e4ea
|
2873 2874 2875 2876 |
[x86] noirqtime: Do not use TSC to do irq accounting. Used to run time disable IRQ_TIME_ACCOUNTING on any platforms where RDTSC is slow and this accounting can add overhead. |
395628ef4
|
2877 |
|
a99130449
|
2878 2879 2880 2881 |
turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface Format: <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> |
1da177e4c
|
2882 |
See also Documentation/input/joystick-parport.txt |
b6935f8cd
|
2883 2884 2885 2886 |
udbg-immortal [PPC] When debugging early kernel crashes that happen after console_init() and before a proper console driver takes over, this boot options might help "seeing" what's going on. |
f86dcc5aa
|
2887 2888 |
uhash_entries= [KNL,NET] Set number of hash buckets for UDP/UDP-Lite connections |
5f8364b7d
|
2889 2890 2891 2892 2893 2894 2895 |
uhci-hcd.ignore_oc= [USB] Ignore overcurrent events (default N). Some badly-designed motherboards generate lots of bogus events, for ports that aren't wired to anything. Set this parameter to avoid log spamming. Note that genuine overcurrent events won't be reported either. |
e3a61b0a8
|
2896 |
unknown_nmi_panic |
44a4dcf75
|
2897 |
[X86] Cause panic on unknown NMI. |
e3a61b0a8
|
2898 |
|
c4fc2342c
|
2899 2900 2901 2902 |
usbcore.authorized_default= [USB] Default USB device authorization: (default -1 = authorized except for wireless USB, 0 = not authorized, 1 = authorized) |
b5e795f8d
|
2903 2904 2905 2906 2907 |
usbcore.autosuspend= [USB] The autosuspend time delay (in seconds) used for newly-detected USB devices (default 2). This is the time required before an idle device will be autosuspended. Devices for which the delay is set |
eaafbc3a8
|
2908 |
to a negative value won't be autosuspended at all. |
b5e795f8d
|
2909 |
|
fd7c519dd
|
2910 2911 2912 2913 2914 2915 2916 2917 2918 |
usbcore.usbfs_snoop= [USB] Set to log all usbfs traffic (default 0 = off). usbcore.blinkenlights= [USB] Set to cycle leds on hubs (default 0 = off). usbcore.old_scheme_first= [USB] Start with the old device initialization scheme (default 0 = off). |
3f5eb8d56
|
2919 2920 2921 |
usbcore.usbfs_memory_mb= [USB] Memory limit (in MB) for buffers allocated by usbfs (default = 16, 0 = max = 2047). |
fd7c519dd
|
2922 2923 2924 2925 2926 2927 2928 2929 |
usbcore.use_both_schemes= [USB] Try the other device initialization scheme if the first one fails (default 1 = enabled). usbcore.initial_descriptor_timeout= [USB] Specifies timeout for the initial 64-byte USB_REQ_GET_DESCRIPTOR request in milliseconds (default 5000 = 5.0 seconds). |
1da177e4c
|
2930 2931 |
usbhid.mousepoll= [USBHID] The interval which mice are to be polled at. |
a99130449
|
2932 |
|
d4f373e57
|
2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 |
usb-storage.delay_use= [UMS] The delay in seconds before a new device is scanned for Logical Units (default 5). usb-storage.quirks= [UMS] A list of quirks entries to supplement or override the built-in unusual_devs list. List entries are separated by commas. Each entry has the form VID:PID:Flags where VID and PID are Vendor and Product ID values (4-digit hex numbers) and Flags is a set of characters, each corresponding to a common usb-storage quirk flag as follows: |
c838ea462
|
2945 2946 |
a = SANE_SENSE (collect more than 18 bytes of sense data); |
a0bb10811
|
2947 2948 |
b = BAD_SENSE (don't collect more than 18 bytes of sense data); |
d4f373e57
|
2949 2950 |
c = FIX_CAPACITY (decrease the reported device capacity by one sector); |
5116901d8
|
2951 2952 2953 2954 |
d = NO_READ_DISC_INFO (don't use READ_DISC_INFO command); e = NO_READ_CAPACITY_16 (don't use READ_CAPACITY_16 command); |
c838ea462
|
2955 2956 2957 |
h = CAPACITY_HEURISTICS (decrease the reported device capacity by one sector if the number is odd); |
d4f373e57
|
2958 2959 2960 2961 2962 2963 |
i = IGNORE_DEVICE (don't bind to this device); l = NOT_LOCKABLE (don't try to lock and unlock ejectable media); m = MAX_SECTORS_64 (don't transfer more than 64 sectors = 32 KB at a time); |
21c13a4f7
|
2964 2965 |
n = INITIAL_READ10 (force a retry of the initial READ(10) command); |
c838ea462
|
2966 2967 |
o = CAPACITY_OK (accept the capacity reported by the device); |
eaa05dfcd
|
2968 2969 |
p = WRITE_CACHE (the device cache is ON by default); |
d4f373e57
|
2970 2971 2972 2973 2974 2975 2976 |
r = IGNORE_RESIDUE (the device reports bogus residue values); s = SINGLE_LUN (the device has only one Logical Unit); w = NO_WP_DETECT (don't test whether the medium is write-protected). Example: quirks=0419:aaf5:rl,0421:0433:rc |
ac1667db0
|
2977 2978 2979 2980 2981 2982 2983 2984 2985 |
user_debug= [KNL,ARM] Format: <int> See arch/arm/Kconfig.debug help text. 1 - undefined instruction events 2 - system calls 4 - invalid data aborts 8 - SIGSEGV faults 16 - SIGBUS faults Example: user_debug=31 |
143155920
|
2986 2987 2988 2989 2990 2991 |
userpte= [X86] Flags controlling user PTE allocations. nohigh = do not allocate PTE pages in HIGHMEM regardless of setting of CONFIG_HIGHPTE. |
6cececfce
|
2992 |
vdso= [X86,SH] |
1dbf527c5
|
2993 |
vdso=2: enable compat VDSO (default with COMPAT_VDSO) |
e6e5494cb
|
2994 2995 |
vdso=1: enable VDSO (default) vdso=0: disable VDSO mapping |
6cececfce
|
2996 |
vdso32= [X86] |
af65d6484
|
2997 2998 2999 |
vdso32=2: enable compat VDSO (default with COMPAT_VDSO) vdso32=1: enable 32-bit VDSO (default) vdso32=0: disable 32-bit VDSO mapping |
d080d397f
|
3000 3001 |
vector= [IA-64,SMP] vector=percpu: enable percpu vector domain |
1da177e4c
|
3002 3003 |
video= [FB] Frame buffer configuration See Documentation/fb/modedb.txt. |
3afe6dab8
|
3004 3005 3006 3007 3008 3009 3010 3011 |
video.brightness_switch_enabled= [0,1] If set to 1, on receiving an ACPI notify event generated by hotkey, video driver will adjust brightness level and then send out the event to user space through the allocated input device; If set to 0, video driver will only send out the event without touching backlight brightness level. default: 1 |
81a054ce0
|
3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 |
virtio_mmio.device= [VMMIO] Memory mapped virtio (platform) device. <size>@<baseaddr>:<irq>[:<id>] where: <size> := size (can use standard suffixes like K, M and G) <baseaddr> := physical base address <irq> := interrupt number (as passed to request_irq()) <id> := (optional) platform device id example: virtio_mmio.device=1K@0x100b0000:48:7 Can be used multiple times for multiple devices. |
cd4f0ef7c
|
3027 |
vga= [BOOT,X86-32] Select a particular video mode |
954a8b816
|
3028 |
See Documentation/x86/boot.txt and |
a99130449
|
3029 |
Documentation/svga.txt. |
1da177e4c
|
3030 3031 3032 |
Use vga=ask for menu. This is actually a boot loader parameter; the value is passed to the kernel using a special protocol. |
a99130449
|
3033 |
vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact |
1da177e4c
|
3034 3035 3036 3037 |
size of <nn>. This can be used to increase the minimum size (128MB on x86). It can also be used to decrease the size and leave more room for directly mapped kernel RAM. |
585c3047a
|
3038 3039 |
vmhalt= [KNL,S390] Perform z/VM CP command after system halt. Format: <command> |
1da177e4c
|
3040 |
|
585c3047a
|
3041 3042 3043 3044 3045 |
vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. Format: <command> vmpoff= [KNL,S390] Perform z/VM CP command after power off. Format: <command> |
a99130449
|
3046 |
|
3ae36655b
|
3047 3048 3049 3050 3051 3052 3053 |
vsyscall= [X86-64] Controls the behavior of vsyscalls (i.e. calls to fixed addresses of 0xffffffffff600x00 from legacy code). Most statically-linked binaries and older versions of glibc use these calls. Because these functions are at fixed addresses, they make nice targets for exploits that can control RIP. |
2e57ae051
|
3054 3055 |
emulate [default] Vsyscalls turn into traps and are emulated reasonably safely. |
3ae36655b
|
3056 |
|
2e57ae051
|
3057 |
native Vsyscalls are native syscall instructions. |
3ae36655b
|
3058 3059 3060 3061 3062 3063 3064 3065 |
This is a little bit faster than trapping and makes a few dynamic recompilers work better than they would in emulation mode. It also makes exploits much easier to write. none Vsyscalls don't work at all. This makes them quite hard to use for exploits but might break your system. |
3855ae1c4
|
3066 3067 3068 |
vt.color= [VT] Default text color. Format: 0xYX, X = foreground, Y = background. Default: 0x07 = light gray on black. |
9ea9a886b
|
3069 3070 3071 3072 |
vt.cur_default= [VT] Default cursor shape. Format: 0xCCBBAA, where AA, BB, and CC are the same as the parameters of the <Esc>[?A;B;Cc escape sequence; see VGA-softcursor.txt. Default: 2 = underline. |
0cb55ad2a
|
3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 |
vt.default_blu= [VT] Format: <blue0>,<blue1>,<blue2>,...,<blue15> Change the default blue palette of the console. This is a 16-member array composed of values ranging from 0-255. vt.default_grn= [VT] Format: <green0>,<green1>,<green2>,...,<green15> Change the default green palette of the console. This is a 16-member array composed of values ranging from 0-255. vt.default_red= [VT] Format: <red0>,<red1>,<red2>,...,<red15> Change the default red palette of the console. This is a 16-member array composed of values ranging from 0-255. vt.default_utf8= [VT] Format=<0|1> Set system-wide default UTF-8 mode for all tty's. Default is 1, i.e. UTF-8 mode is enabled for all newly opened terminals. |
f6c06b680
|
3097 3098 3099 3100 3101 3102 3103 3104 |
vt.global_cursor_default= [VT] Format=<-1|0|1> Set system-wide default for whether a cursor is shown on new VTs. Default is -1, i.e. cursors will be created by default unless overridden by individual drivers. 0 will hide cursors, 1 will display them. |
3855ae1c4
|
3105 3106 3107 3108 3109 |
vt.italic= [VT] Default color for italic text; 0-15. Default: 2 = green. vt.underline= [VT] Default color for underlined text; 0-15. Default: 3 = cyan. |
4724ba575
|
3110 3111 3112 3113 |
watchdog timers [HW,WDT] For information on watchdog timers, see Documentation/watchdog/watchdog-parameters.txt or other driver-specific files in the Documentation/watchdog/ directory. |
1da177e4c
|
3114 |
|
d55262c4d
|
3115 3116 3117 3118 3119 3120 3121 3122 |
workqueue.disable_numa By default, all work items queued to unbound workqueues are affine to the NUMA nodes they're issued on, which results in better behavior in general. If NUMA affinity needs to be disabled for whatever reason, this option can be used. Note that this also can be controlled per-workqueue for workqueues visible under /sys/bus/workqueue/. |
cee22a150
|
3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 |
workqueue.power_efficient Per-cpu workqueues are generally preferred because they show better performance thanks to cache locality; unfortunately, per-cpu workqueues tend to be more power hungry than unbound workqueues. Enabling this makes the per-cpu workqueues which were observed to contribute significantly to power consumption unbound, leading to measurably lower power usage at the cost of small performance overhead. The default value of this parameter is determined by the config option CONFIG_WQ_POWER_EFFICIENT_DEFAULT. |
0cb55ad2a
|
3137 3138 3139 |
x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of default x2apic cluster mode on platforms supporting x2apic. |
bb24c4716
|
3140 3141 3142 3143 3144 |
x86_mrst_timer= [X86-32,APBT] Choose timer option for x86 Moorestown MID platform. Two valid options are apbt timer only and lapic timer plus one apbt timer for broadcast timer. x86_mrst_timer=apbt_only | lapic_and_apbt |
c1c5413ad
|
3145 3146 3147 3148 3149 3150 3151 |
xen_emul_unplug= [HW,X86,XEN] Unplug Xen emulated devices Format: [unplug0,][unplug1] ide-disks -- unplug primary master IDE devices aux-ide-disks -- unplug non-primary-master IDE devices nics -- unplug network devices all -- unplug all emulated devices (NICs and IDE disks) |
1dc7ce99b
|
3152 3153 3154 |
unnecessary -- unplugging emulated devices is unnecessary even if the host did not respond to the unplug protocol |
c93a4dfb3
|
3155 |
never -- do not unplug even if version check succeeds |
c1c5413ad
|
3156 |
|
1da177e4c
|
3157 |
xirc2ps_cs= [NET,PCMCIA] |
a99130449
|
3158 3159 |
Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] |
1da177e4c
|
3160 |
|
a99130449
|
3161 |
______________________________________________________________________ |
1da177e4c
|
3162 3163 |
TODO: |
1da177e4c
|
3164 |
Add more DRM drivers. |