X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=Documentation%2Fkernel-parameters.txt;h=b3a6187e53051866004696e4d5718cd85240e1c2;hb=7114b0bb6df7b2db266ba4847e4dd8333fa98a9a;hp=0dc848bf0b56bb59b0c69eacfc3fb4d6a593fb7c;hpb=a61c2d78ce61e67baf27c43f6721db87a27ac762;p=safe%2Fjmp%2Flinux-2.6 diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 0dc848b..b3a6187 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. @@ -49,6 +57,7 @@ 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. @@ -335,6 +344,12 @@ running once the system is up. timesource is not avalible, it defaults to PIT. Format: { pit | tsc | cyclone | pmtmr } + 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 +375,17 @@ 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] @@ -452,6 +472,11 @@ running once the system is up. eata= [HW,SCSI] + ec_intr= [HW,ACPI] ACPI Embedded Controller interrupt mode + Format: + 0: polling mode + non-0: interrupt mode (default) + eda= [HW,PS2] edb= [HW,PS2] @@ -471,14 +496,15 @@ running once the system is up. arch/i386/kernel/cpu/cpufreq/elanfreq.c. elevator= [IOSCHED] - Format: {"as" | "cfq" | "deadline" | "noop"} + Format: {"anticipatory" | "cfq" | "deadline" | "noop"} See Documentation/block/as-iosched.txt and Documentation/block/deadline-iosched.txt for details. - elfcorehdr= [IA-32] + elfcorehdr= [IA-32, X86_64] Specifies physical address of start of kernel core - image elf header. - See Documentation/kdump.txt for details. + image elf header. Generally kexec loader will + pass this option to capture kernel. + See Documentation/kdump/kdump.txt for details. enforcing [SELINUX] Set initial enforcing status. Format: {"0" | "1"} @@ -711,9 +737,17 @@ running once the system is up. load_ramdisk= [RAM] List of ramdisks to load from floppy See Documentation/ramdisk.txt. - lockd.udpport= [NFS] + lockd.nlm_grace_period=P [NFS] Assign grace period. + Format: - lockd.tcpport= [NFS] + lockd.nlm_tcpport=N [NFS] Assign TCP port. + Format: + + lockd.nlm_timeout=T [NFS] Assign timeout value. + Format: + + lockd.nlm_udpport=M [NFS] Assign UDP port. + Format: logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver Format: @@ -832,7 +866,7 @@ running once the system is up. mem=nopentium [BUGS=IA-32] Disable usage of 4MB pages for kernel memory. - memmap=exactmap [KNL,IA-32] Enable setting of an exact + memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact 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 @@ -855,6 +889,49 @@ running once the system is up. mga= [HW,DRM] + migration_cost= + [KNL,SMP] debug: override scheduler migration costs + Format: ,,... + This debugging option can be used to override the + default scheduler migration cost matrix. The numbers + are indexed by 'CPU domain distance'. + E.g. migration_cost=1000,2000,3000 on an SMT NUMA + box will set up an intra-core migration cost of + 1 msec, an inter-core migration cost of 2 msecs, + and an inter-node migration cost of 3 msecs. + + WARNING: using the wrong values here can break + scheduler performance, so it's only for scheduler + development purposes, not production environments. + + migration_debug= + [KNL,SMP] migration cost auto-detect verbosity + Format=<0|1|2> + If a system's migration matrix reported at bootup + seems erroneous then this option can be used to + increase verbosity of the detection process. + We default to 0 (no extra messages), 1 will print + some more information, and 2 will be really + verbose (probably only useful if you also have a + serial console attached to the system). + + migration_factor= + [KNL,SMP] multiply/divide migration costs by a factor + Format= + This debug option can be used to proportionally + increase or decrease the auto-detected migration + costs for all entries of the migration matrix. + E.g. migration_factor=150 will increase migration + costs by 50%. (and thus the scheduler will be less + eager migrating cache-hot tasks) + migration_factor=80 will decrease migration costs + by 20%. (thus the scheduler will be more eager to + migrate tasks) + + WARNING: using the wrong values here can break + scheduler performance, so it's only for scheduler + development purposes, not production environments. + mousedev.tap_time= [MOUSE] Maximum time between finger touching and leaving touchpad surface for touch to be considered @@ -945,7 +1022,9 @@ 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] @@ -975,6 +1054,8 @@ running once the system is up. 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 noresidual [PPC] Don't use residual data on PReP machines. @@ -988,6 +1069,8 @@ 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. @@ -1057,6 +1140,11 @@ running once the system is up. pas16= [HW,SCSI] See header of drivers/scsi/pas16.c. + 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. + pcbit= [HW,ISDN] pcd. [PARIDE] @@ -1076,6 +1164,11 @@ running once the system is up. Mechanism 1. conf2 [IA-32] Force use of PCI Configuration Mechanism 2. + nommconf [IA-32,X86_64] Disable use of MMCONFIG for PCI + Configuration + 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. nosort [IA-32] Don't sort PCI devices according to order given by the PCI BIOS. This sorting is done to get a device order compatible with @@ -1223,6 +1316,19 @@ 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. + + rcu.rsinterval= [KNL,BOOT,SMP] Set the number of additional + RCU callbacks to queued before forcing reschedule + on all cpus. + rdinit= [KNL] Format: Run specified binary instead of /init from the ramdisk, @@ -1579,22 +1685,11 @@ running once the system is up. Format: ,,,,,[,[,[,]]] + norandmaps Don't use address space randomization + Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space -______________________________________________________________________ -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: