X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=Documentation%2Fkernel-parameters.txt;h=09220a1e22d964b3ad19a235952a77c2bd9d1cef;hb=640b31bf1291d1fb8a3e90abed8f145410122bf8;hp=75205391b335f85c9b8a599d0d3b4c0dd1a8b41b;hpb=312f1f0141627a58bf72c55f0e7bc5d6f118a372;p=safe%2Fjmp%2Flinux-2.6 diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 75205391..09220a1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1,4 +1,4 @@ -February 2003 Kernel Parameters v2.5.59 + Kernel Parameters ~~~~~~~~~~~~~~~~~ The following is a consolidated list of the kernel parameters as implemented @@ -17,9 +17,17 @@ are specified on the kernel command line with the module name plus usbcore.blinkenlights=1 -The text in square brackets at the beginning of the description states the -restrictions on the kernel for the said kernel parameter to be valid. The -restrictions referred to are that the relevant option is valid if: +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}". + +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: ACPI ACPI support is enabled. ALSA ALSA sound support is enabled. @@ -27,7 +35,6 @@ restrictions referred to are that the relevant option is valid if: APM Advanced Power Management support is enabled. AX25 Appropriate AX.25 support is enabled. CD Appropriate CD support is enabled. - DEVFS devfs support is enabled. DRM Direct Rendering Management support is enabled. EDD BIOS Enhanced Disk Drive Services (EDD) is enabled EFI EFI Partitioning (GPT) is enabled @@ -41,6 +48,7 @@ restrictions referred to are that the relevant option is valid if: ISAPNP ISA PnP code is enabled. ISDN Appropriate ISDN support is enabled. JOY Appropriate joystick support is enabled. + LIBATA Libata driver is enabled LP Printer support is enabled. LOOP Loopback device support is enabled. M68k M68k architecture is enabled. @@ -49,11 +57,14 @@ restrictions referred to are that the relevant option is valid if: MCA MCA bus support is enabled. MDA MDA console support is enabled. MOUSE Appropriate mouse support is enabled. + MSI Message Signaled Interrupts (PCI). MTD MTD support is enabled. NET Appropriate network support is enabled. NUMA NUMA support is enabled. + GENERIC_TIME The generic timeofday code is enabled. NFS Appropriate NFS support is enabled. OSS OSS sound support is enabled. + PV_OPS A paravirtualized kernel PARIDE The ParIDE subsystem is enabled. PARISC The PA-RISC architecture is enabled. PCI PCI bus support is enabled. @@ -69,6 +80,7 @@ restrictions referred to are that the relevant option is valid if: Documentation/scsi/. SELINUX SELinux support is enabled. SERIAL Serial support is enabled. + SH SuperH architecture is enabled. SMP The kernel is an SMP kernel. SPARC Sparc architecture is enabled. SWSUSP Software suspend is enabled. @@ -95,17 +107,28 @@ loader, and have no meaning to the kernel directly. Do not modify the syntax of boot loader parameters without extreme need or coordination with . +There are also arch-specific kernel-parameters not documented here. +See for example . + 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. +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. + + 53c7xx= [HW,SCSI] Amiga SCSI controllers See header of drivers/scsi/53c7xx.c. See also Documentation/scsi/ncr53c7xx.txt. - acpi= [HW,ACPI] Advanced Configuration and Power Interface + acpi= [HW,ACPI,X86-64,i386] + Advanced Configuration and Power Interface Format: { force | off | ht | strict | noirq } force -- enable ACPI if default was off off -- disable ACPI if default was on @@ -116,6 +139,12 @@ running once the system is up. See also Documentation/pm.txt, pci=noacpi + acpi_apic_instance= [ACPI, IOAPIC] + Format: + 2: use 2nd APIC table, if available + 1,0: use 1st APIC table + default: 0 + acpi_sleep= [HW,ACPI] Sleep options Format: { s3_bios, s3_mode } See Documentation/power/video.txt @@ -138,6 +167,9 @@ running once the system is up. acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA Format: ,... + 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] empty param disables _OSI acpi_serialize [HW,ACPI] force serialization of AML methods @@ -145,20 +177,46 @@ running once the system is up. acpi_skip_timer_override [HW,ACPI] Recognize and ignore IRQ0/pin2 Interrupt Override. For broken nForce2 BIOS resulting in XT-PIC timer. + 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 - acpi_dbg_layer= [HW,ACPI] + acpi.debug_layer= [HW,ACPI] Format: Each bit of the indicates an ACPI debug layer, 1: enable, 0: disable. It is useful for boot time debugging. After system has booted up, it can be set - via /proc/acpi/debug_layer. - - acpi_dbg_level= [HW,ACPI] + via /sys/module/acpi/parameters/debug_layer. + CONFIG_ACPI_DEBUG must be enabled for this to produce any output. + Available bits (add the numbers together) to enable debug output + for specific parts of the ACPI subsystem: + 0x01 utilities 0x02 hardware 0x04 events 0x08 tables + 0x10 namespace 0x20 parser 0x40 dispatcher + 0x80 executer 0x100 resources 0x200 acpica debugger + 0x400 os services 0x800 acpica disassembler. + The number can be in decimal or prefixed with 0x in hex. + Warning: Many of these options can produce a lot of + output and make your system unusable. Be very careful. + + acpi.debug_level= [HW,ACPI] Format: Each bit of the indicates an ACPI debug level, 1: enable, 0: disable. It is useful for boot time debugging. After system has booted up, it can be set - via /proc/acpi/debug_level. + via /sys/module/acpi/parameters/debug_level. + CONFIG_ACPI_DEBUG must be enabled for this to produce any output. + Available bits (add the numbers together) to enable different + debug output levels of the ACPI subsystem: + 0x01 error 0x02 warn 0x04 init 0x08 debug object + 0x10 info 0x20 init names 0x40 parse 0x80 load + 0x100 dispatch 0x200 execute 0x400 names 0x800 operation region + 0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects + 0x10000 resources 0x20000 user requests 0x40000 package. + The number can be in decimal or prefixed with 0x in hex. + Warning: Many of these options can produce a lot of + output and make your system unusable. Be very careful. + acpi_fake_ecdt [HW,ACPI] Workaround failure due to BIOS lacking ECDT @@ -167,6 +225,11 @@ running once the system is up. override platform specific driver. See also Documentation/acpi-hotkey.txt. + acpi_pm_good [IA-32,X86-64] + Override the pmtimer bug detection: force the kernel + to assume that this machine's pmtimer latches its value + and always returns good values. + enable_timer_pin_1 [i386,x86-64] Enable PIN 1 of APIC timer Can be useful to work around chipset bugs @@ -265,9 +328,6 @@ running once the system is up. autotest [IA64] - awe= [HW,OSS] AWE32/SB32/AWE64 wave table synth - Format: ,, - aztcd= [HW,CD] Aztech CD268 CDROM driver Format: ,0x79 (?) @@ -329,12 +389,24 @@ running once the system is up. Value can be changed at runtime via /selinux/checkreqprot. - clock= [BUGS=IA-32,HW] gettimeofday timesource override. - Forces specified timesource (if avaliable) to be used - when calculating gettimeofday(). If specicified - timesource is not avalible, it defaults to PIT. + clock= [BUGS=IA-32, HW] gettimeofday clocksource override. + [Deprecated] + Forces specified clocksource (if available) to be used + when calculating gettimeofday(). If specified + clocksource is not available, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } + code_bytes [IA32] How many bytes of object code to print in an + oops report. + Range: 0 - 8192 + Default: 64 + + disable_8254_timer + enable_8254_timer + [IA32/X86_64] Disable/Enable interrupt 0 timer routing + over the 8254 in addition to over the IO-APIC. The + kernel tries to set a sensible default. + hpet= [IA-32,HPET] option to disable HPET and use PIT. Format: disable @@ -360,12 +432,17 @@ running once the system is up. tty Use the virtual console device . ttyS[,options] + ttyUSB0[,options] Use the specified serial port. The options are of - the form "bbbbpn", where "bbbb" is the baud rate, - "p" is parity ("n", "o", or "e"), and "n" is bits. - Default is "9600n8". + 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 also Documentation/serial-console.txt. + See Documentation/serial-console.txt for more + information. See + Documentation/networking/netconsole.txt for an + alternative. uart,io,[,options] uart,mmio,[,options] @@ -406,12 +483,42 @@ running once the system is up. debug [KNL] Enable kernel debugging (events log level). + 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. + decnet= [HW,NET] Format: [,] See also Documentation/networking/decnet.txt. - devfs= [DEVFS] - See Documentation/filesystems/devfs/boot-options. + default_blu= [VT] + Format: ,,,..., + Change the default blue palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + default_grn= [VT] + Format: ,,,..., + Change the default green palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + default_red= [VT] + Format: ,,,..., + Change the default red palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + default_utf8= [VT] + Format=<0|1> + Set system-wide default UTF-8 mode for all tty's. + Default is 0 and by setting to 1, it enables UTF-8 + mode for all newly opened or allocated terminals. dhash_entries= [KNL] Set number of hash buckets for dentry cache. @@ -433,7 +540,7 @@ running once the system is up. dtc3181e= [HW,SCSI] - earlyprintk= [IA-32,X86-64] + earlyprintk= [IA-32,X86-64,SH] earlyprintk=vga earlyprintk=serial[,ttySn[,baudrate]] @@ -494,10 +601,6 @@ running once the system is up. Default value is 0. Value can be changed at runtime via /selinux/enforce. - es1370= [HW,OSS] - Format: [,] - See also header of sound/oss/es1370.c. - es1371= [HW,OSS] Format: ,[,[]] See also header of sound/oss/es1371.c. @@ -509,6 +612,13 @@ running once the system is up. eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog. Format: [,] + failslab= + fail_page_alloc= + fail_make_request=[KNL] + General fault injection mechanism. + Format: ,,, + See also /Documentation/fault-injection/. + fd_mcs= [HW,SCSI] See header of drivers/scsi/fd_mcs.c. @@ -518,9 +628,6 @@ running once the system is up. floppy= [HW] See Documentation/floppy.txt. - ftape= [HW] Floppy Tape subsystem debugging options. - See Documentation/ftape.txt. - gamecon.map[2|3]= [HW,JOY] Multisystem joystick and NES/SNES/PSX pad support via parallel port (up to 5 devices per port) @@ -538,11 +645,6 @@ running once the system is up. gscd= [HW,CD] Format: - gt96100eth= [NET] MIPS GT96100 Advanced Communication Controller - - gus= [HW,OSS] - Format: ,,, - gvp11= [HW,SCSI] hashdist= [KNL,NUMA] Large hashes allocated during boot @@ -563,16 +665,18 @@ running once the system is up. highmem otherwise. This also works to reduce highmem size on bigger boxes. + highres= [KNL] Enable/disable high resolution timer mode. + Valid parameters: "on", "off" + Default: "on" + hisax= [HW,ISDN] See Documentation/isdn/README.HiSax. hugepages= [HW,IA-32,IA-64] Maximal number of HugeTLB pages. - noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing - i8042.direct [HW] Put keyboard port into non-translated mode - i8042.dumbkbd [HW] Pretend that controlled can only read data from - keyboard and can not control its state + i8042.dumbkbd [HW] Pretend that controller can only read data from + keyboard and cannot control its state (Don't attempt to blink the leds) i8042.noaux [HW] Don't check for auxiliary (== mouse) port i8042.nokbd [HW] Don't check/create keyboard port @@ -616,8 +720,19 @@ running once the system is up. idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed See Documentation/ide.txt. - idle= [HW] - Format: idle=poll or idle=halt + idle= [X86] + Format: idle=poll or idle=mwait + Poll forces a polling idle loop that can slightly improves the performance + of waking up a idle CPU, but will use a lot of power and make the system + run hot. Not recommended. + idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose + to not use it because it doesn't save as much power as a normal idle + loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same + as idle=poll. + + ignore_loglevel [KNL] + Ignore loglevel setting - this will print /all/ + kernel messages to the console. Useful for debugging. ihash_entries= [KNL] Set number of hash buckets for inode cache. @@ -639,14 +754,6 @@ running once the system is up. inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver Format: - combined_mode= [HW] control which driver uses IDE ports in combined - mode: legacy IDE driver, libata, or both - (in the libata case, libata.atapi_enabled=1 may be - useful as well). Note that using the ide or libata - options may affect your device naming (e.g. by - changing hdc to sdb). - Format: combined (default), ide, or libata - inttest= [IA64] io7= [HW] IO7 for Marvel based alpha systems @@ -662,6 +769,12 @@ running once the system is up. ips= [HW,SCSI] Adaptec / IBM ServeRAID controller See header of drivers/scsi/ips.c. + ports= [IP_VS_FTP] IPVS ftp helper module + Default is 21. + Up to 8 (IP_VS_APP_MAX_PORTS) ports + may be specified. + Format: ,.... + irqfixup [HW] When an interrupt is not handled search all handlers for it. Intended to get systems with badly broken @@ -677,7 +790,12 @@ running once the system is up. Format: ,,, isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler. - Format: ,..., + Format: + ,..., + or + - (must be a positive range in ascending order) + or a mixture + ,...,- This option can be used to specify one or more CPUs to isolate from the general SMP balancing and scheduling algorithms. The only way to move a process onto or off @@ -708,9 +826,17 @@ running once the system is up. lapic [IA-32,APIC] Enable the local APIC even if BIOS disabled it. + lapic_timer_c2_ok [IA-32,x86-64,APIC] trust the local apic timer in + C2 power state. + lasi= [HW,SCSI] PARISC LASI driver for the 53c700 chip Format: addr:,irq: + legacy_serial.force [HW,IA-32,X86-64] + Probe for COM ports at legacy addresses even + if PNPBIOS or ACPI should describe them. This + is for working around firmware defects. + llsc*= [IA64] See function print_params() in arch/ia64/sn/kernel/llsc4.c. @@ -795,18 +921,19 @@ running once the system is up. (machvec) in a generic kernel. Example: machvec=hpzx1_swiotlb - mad16= [HW,OSS] Format: - ,,,,,, - - maui= [HW,OSS] - Format: , - max_loop= [LOOP] Maximum number of loopback devices that can be mounted Format: <1-256> maxcpus= [SMP] Maximum number of processors that an SMP kernel - should make use of + should make use of. + Using "nosmp" or "maxcpus=0" will disable SMP + entirely (the MPS table probe still happens, though). + A command-line option of "maxcpus=", where + is an integer greater than 0, limits the maximum number + of CPUs activated in SMP mode to . + Using "maxcpus=1" on an SMP kernel is the trivial + case of an SMP kernel with only one CPU. max_addr=[KMG] [KNL,BOOT,ia64] All physical memory greater than or equal to this physical address is ignored. @@ -981,6 +1108,14 @@ running once the system is up. emulation library even if a 387 maths coprocessor is present. + noacpi [LIBATA] Disables use of ACPI in libata suspend/resume + when set. + Format: + + noaliencache [MM, NUMA] Disables the allcoation of alien caches in + the slab allocator. Saves per-node memory, but will + impact performance on real NUMA hardware. + noalign [KNL,ARM] noapic [SMP,APIC] Tells the kernel to not make use of any @@ -994,6 +1129,8 @@ running once the system is up. nocache [ARM] + nodelayacct [KNL] Disable per-task delay accounting + nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. noexec [IA-64] @@ -1002,7 +1139,9 @@ running once the system is up. noexec=on: enable non-executable mappings (default) noexec=off: disable nn-executable mappings - nofxsr [BUGS=IA-32] + nofxsr [BUGS=IA-32] Disables x86 floating point extended + register save and restore. The kernel will only save + legacy floating-point registers on task switch. nohlt [BUGS=ARM] @@ -1017,9 +1156,18 @@ running once the system is up. in certain environments such as networked servers or real-time systems. + nohz= [KNL] Boottime enable/disable dynamic ticks + Valid arguments: on, off + Default: on + + noirqbalance [IA-32,SMP,KNL] Disable kernel irq balancing + noirqdebug [IA-32] Disables the code which attempts to detect and disable unhandled interrupt sources. + no_timer_check [IA-32,X86_64,APIC] Disables the code which tests for + broken timer IRQ sources. + noisapnp [ISAPNP] Disables ISA PnP code. noinitrd [RAM] Tells the kernel not to load any configured @@ -1029,12 +1177,19 @@ running once the system is up. nolapic [IA-32,APIC] Do not enable or use the local APIC. + nolapic_timer [IA-32,APIC] Do not use the local APIC timer. + noltlbs [PPC] Do not use large page/tlb entries for kernel lowmem mapping on PPC40x. + nomca [IA-64] Disable machine check abort handling + nomce [IA-32] Machine Check Exception - nomca [IA-64] Disable machine check abort handling + noreplace-paravirt [IA-32,PV_OPS] Don't patch paravirt_ops + + noreplace-smp [IA-32,SMP] Don't replace SMP instructions + with UP alternatives noresidual [PPC] Don't use residual data on PReP machines. @@ -1047,6 +1202,8 @@ running once the system is up. nosbagart [IA-64] + nosep [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support. + nosmp [SMP] Tells an SMP kernel to act as a UP kernel. nosync [HW,M68K] Disables sync negotiation for all devices. @@ -1062,9 +1219,6 @@ running once the system is up. opl3= [HW,OSS] Format: - opl3sa= [HW,OSS] - Format: ,,,,, - opl3sa2= [HW,OSS] Format: ,,,,,,,[,, - step/bucket size as a power of 2 for statistical time based profiling. + Param: "sleep" - profile D-state sleeping (millisecs) processor.max_cstate= [HW,ACPI] Limit processor to maximum C-state @@ -1267,7 +1445,7 @@ running once the system is up. pt. [PARIDE] See Documentation/paride.txt. - quiet= [KNL] Disable log messages + quiet [KNL] Disable most log messages r128= [HW,DRM] @@ -1284,6 +1462,15 @@ running once the system is up. New name for the ramdisk parameter. See Documentation/ramdisk.txt. + rcu.blimit= [KNL,BOOT] Set maximum number of finished + RCU callbacks to process in one batch. + + rcu.qhimark= [KNL,BOOT] Set threshold of queued + RCU callbacks over which batch limiting is disabled. + + rcu.qlowmark= [KNL,BOOT] Set threshold of queued + RCU callbacks below which batch limiting is re-enabled. + rdinit= [KNL] Format: Run specified binary instead of /init from the ramdisk, @@ -1291,13 +1478,29 @@ running once the system is up. reboot= [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode Format: [,[,...]] - See arch/*/kernel/reboot.c. + See arch/*/kernel/reboot.c or arch/*/kernel/process.c reserve= [KNL,BUGS] Force the kernel to ignore some iomem area + reservetop= [IA-32] + Format: nn[KMG] + Reserves a hole at the top of the kernel virtual + address space. + + reset_devices [KNL] Force drivers to reset the underlying device + during initialization. + resume= [SWSUSP] Specify the partition device for software suspend + resume_offset= [SWSUSP] + Specify the offset from the beginning of the partition + given by "resume=" at which the swap header is located, + in units (needed only for swap files). + See Documentation/power/swsusp-and-swap-files.txt + + retain_initrd [RAM] Keep initrd memory after extraction + rhash_entries= [KNL,NET] Set number of hash buckets for route cache @@ -1348,6 +1551,11 @@ running once the system is up. scsi_logging= [SCSI] + scsi_mod.scan= [SCSI] sync (default) scans SCSI busses as they are + discovered. async scans them in kernel threads, + allowing boot to proceed. none ignores them, expecting + user space to do the scan. + selinux [SELINUX] Disable or enable SELinux at boot time. Format: { "0" | "1" } See security/selinux/Kconfig help text. @@ -1357,13 +1565,19 @@ running once the system is up. If enabled at boot time, /selinux/disable can be used later to disable prior to initial policy load. + selinux_compat_net = + [SELINUX] Set initial selinux_compat_net flag value. + Format: { "0" | "1" } + 0 -- use new secmark-based packet controls + 1 -- use legacy packet controls + Default value is 0 (preferred). + Value can be changed at runtime via + /selinux/compat_net. + serialnumber [BUGS=IA-32] sg_def_reserved_size= [SCSI] - sgalaxy= [HW,OSS] - Format: ,,,, - shapers= [NET] Maximal number of shapers. @@ -1382,6 +1596,20 @@ running once the system is up. smart2= [HW] Format: [,[,...,]] + smp-alt-once [IA-32,SMP] On a hotplug CPU system, only + attempt to substitute SMP alternatives once at boot. + + 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 + snd-ad1816a= [HW,ALSA] snd-ad1848= [HW,ALSA] @@ -1504,9 +1732,6 @@ running once the system is up. snd-ymfpci= [HW,ALSA] - sonicvibes= [HW,OSS] - Format: - sonycd535= [HW,CD] Format: [,] @@ -1543,6 +1768,22 @@ running once the system is up. stifb= [HW] Format: bpp:[:[:...]] + 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) + swiotlb= [IA-64] Number of I/O TLB slabs switches= [HW,M68k] @@ -1550,6 +1791,12 @@ running once the system is up. sym53c416= [HW,SCSI] See header of drivers/scsi/sym53c416.c. + sysrq_always_enabled + [KNL] + Ignore sysrq setting - this boot parameter will + neutralize any effect of /proc/sys/kernel/sysrq. + Useful for debugging. + t128= [HW,SCSI] See header of drivers/scsi/t128.c. @@ -1560,6 +1807,10 @@ running once the system is up. time Show timing data prefixed to each printk message line + clocksource= [GENERIC_TIME] Override the default clocksource + Override the default clocksource and use the clocksource + with the name specified. + tipar.timeout= [HW,PPT] Set communications timeout in tenths of a second (default 15). @@ -1598,9 +1849,29 @@ running once the system is up. uart6850= [HW,OSS] Format: , + 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. + + 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 + to a negative value won't be autosuspended at all. + usbhid.mousepoll= [USBHID] The interval which mice are to be polled at. + vdso= [IA-32,SH] + vdso=2: enable compat VDSO (default with COMPAT_VDSO) + vdso=1: enable VDSO (default) + vdso=0: disable VDSO mapping + video= [FB] Frame buffer configuration See Documentation/fb/modedb.txt. @@ -1617,9 +1888,14 @@ running once the system is up. decrease the size and leave more room for directly mapped kernel RAM. - vmhalt= [KNL,S390] + vmhalt= [KNL,S390] Perform z/VM CP command after system halt. + Format: - vmpoff= [KNL,S390] + vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic. + Format: + + vmpoff= [KNL,S390] Perform z/VM CP command after power off. + Format: waveartist= [HW,OSS] Format: ,,, @@ -1643,22 +1919,11 @@ running once the system is up. norandmaps Don't use address space randomization Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space + unwind_debug=N N > 0 will enable dwarf2 unwinder debugging + This is useful to get more information why + you got a "dwarf2 unwinder stuck" ______________________________________________________________________ -Changelog: - -2000-06-?? Mr. Unknown - The last known update (for 2.4.0) - the changelog was not kept before. - -2002-11-24 Petr Baudis - Randy Dunlap - Update for 2.5.49, description for most of the options introduced, - references to other documentation (C files, READMEs, ..), added S390, - PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and - reformatting. - -2005-10-19 Randy Dunlap - Lots of typos, whitespace, some reformatting. TODO: