aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/kernel-parameters.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r--Documentation/kernel-parameters.txt71
1 files changed, 58 insertions, 13 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 60b98cea06fc..1205505798cc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -49,6 +49,7 @@ parameter is applicable:
49 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled 49 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
50 EFI EFI Partitioning (GPT) is enabled 50 EFI EFI Partitioning (GPT) is enabled
51 EIDE EIDE/ATAPI support is enabled. 51 EIDE EIDE/ATAPI support is enabled.
52 EVM Extended Verification Module
52 FB The frame buffer device is enabled. 53 FB The frame buffer device is enabled.
53 FTRACE Function tracing enabled. 54 FTRACE Function tracing enabled.
54 GCOV GCOV profiling is enabled. 55 GCOV GCOV profiling is enabled.
@@ -163,7 +164,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
163 rsdt -- prefer RSDT over (default) XSDT 164 rsdt -- prefer RSDT over (default) XSDT
164 copy_dsdt -- copy DSDT to memory 165 copy_dsdt -- copy DSDT to memory
165 166
166 See also Documentation/power/pm.txt, pci=noacpi 167 See also Documentation/power/runtime_pm.txt, pci=noacpi
167 168
168 acpi_rsdp= [ACPI,EFI,KEXEC] 169 acpi_rsdp= [ACPI,EFI,KEXEC]
169 Pass the RSDP address to the kernel, mostly used 170 Pass the RSDP address to the kernel, mostly used
@@ -306,6 +307,19 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
306 behaviour to be specified. Bit 0 enables warnings, 307 behaviour to be specified. Bit 0 enables warnings,
307 bit 1 enables fixups, and bit 2 sends a segfault. 308 bit 1 enables fixups, and bit 2 sends a segfault.
308 309
310 align_va_addr= [X86-64]
311 Align virtual addresses by clearing slice [14:12] when
312 allocating a VMA at process creation time. This option
313 gives you up to 3% performance improvement on AMD F15h
314 machines (where it is enabled by default) for a
315 CPU-intensive style benchmark, and it can vary highly in
316 a microbenchmark depending on workload and compiler.
317
318 1: only for 32-bit processes
319 2: only for 64-bit processes
320 on: enable for both 32- and 64-bit processes
321 off: disable for both 32- and 64-bit processes
322
309 amd_iommu= [HW,X86-84] 323 amd_iommu= [HW,X86-84]
310 Pass parameters to the AMD IOMMU driver in the system. 324 Pass parameters to the AMD IOMMU driver in the system.
311 Possible values are: 325 Possible values are:
@@ -319,7 +333,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
319 amijoy.map= [HW,JOY] Amiga joystick support 333 amijoy.map= [HW,JOY] Amiga joystick support
320 Map of devices attached to JOY0DAT and JOY1DAT 334 Map of devices attached to JOY0DAT and JOY1DAT
321 Format: <a>,<b> 335 Format: <a>,<b>
322 See also Documentation/kernel/input/joystick.txt 336 See also Documentation/input/joystick.txt
323 337
324 analog.map= [HW,JOY] Analog joystick and gamepad support 338 analog.map= [HW,JOY] Analog joystick and gamepad support
325 Specifies type or capabilities of an analog joystick 339 Specifies type or capabilities of an analog joystick
@@ -408,7 +422,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
408 bttv.radio= Most important insmod options are available as 422 bttv.radio= Most important insmod options are available as
409 kernel args too. 423 kernel args too.
410 bttv.pll= See Documentation/video4linux/bttv/Insmod-options 424 bttv.pll= See Documentation/video4linux/bttv/Insmod-options
411 bttv.tuner= and Documentation/video4linux/bttv/CARDLIST 425 bttv.tuner=
412 426
413 bulk_remove=off [PPC] This parameter disables the use of the pSeries 427 bulk_remove=off [PPC] This parameter disables the use of the pSeries
414 firmware feature for flushing multiple hpte entries 428 firmware feature for flushing multiple hpte entries
@@ -724,13 +738,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
724 738
725 elevator= [IOSCHED] 739 elevator= [IOSCHED]
726 Format: {"cfq" | "deadline" | "noop"} 740 Format: {"cfq" | "deadline" | "noop"}
727 See Documentation/block/as-iosched.txt and 741 See Documentation/block/cfq-iosched.txt and
728 Documentation/block/deadline-iosched.txt for details. 742 Documentation/block/deadline-iosched.txt for details.
729 743
730 elfcorehdr= [IA-64,PPC,SH,X86] 744 elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390]
731 Specifies physical address of start of kernel core 745 Specifies physical address of start of kernel core
732 image elf header. Generally kexec loader will 746 image elf header and optionally the size. Generally
733 pass this option to capture kernel. 747 kexec loader will pass this option to capture kernel.
734 See Documentation/kdump/kdump.txt for details. 748 See Documentation/kdump/kdump.txt for details.
735 749
736 enable_mtrr_cleanup [X86] 750 enable_mtrr_cleanup [X86]
@@ -760,12 +774,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
760 This option is obsoleted by the "netdev=" option, which 774 This option is obsoleted by the "netdev=" option, which
761 has equivalent usage. See its documentation for details. 775 has equivalent usage. See its documentation for details.
762 776
777 evm= [EVM]
778 Format: { "fix" }
779 Permit 'security.evm' to be updated regardless of
780 current integrity status.
781
763 failslab= 782 failslab=
764 fail_page_alloc= 783 fail_page_alloc=
765 fail_make_request=[KNL] 784 fail_make_request=[KNL]
766 General fault injection mechanism. 785 General fault injection mechanism.
767 Format: <interval>,<probability>,<space>,<times> 786 Format: <interval>,<probability>,<space>,<times>
768 See also /Documentation/fault-injection/. 787 See also Documentation/fault-injection/.
769 788
770 floppy= [HW] 789 floppy= [HW]
771 See Documentation/blockdev/floppy.txt. 790 See Documentation/blockdev/floppy.txt.
@@ -954,6 +973,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
954 ignore_loglevel [KNL] 973 ignore_loglevel [KNL]
955 Ignore loglevel setting - this will print /all/ 974 Ignore loglevel setting - this will print /all/
956 kernel messages to the console. Useful for debugging. 975 kernel messages to the console. Useful for debugging.
976 We also add it as printk module parameter, so users
977 could change it dynamically, usually by
978 /sys/module/printk/parameters/ignore_loglevel.
957 979
958 ihash_entries= [KNL] 980 ihash_entries= [KNL]
959 Set number of hash buckets for inode cache. 981 Set number of hash buckets for inode cache.
@@ -1014,10 +1036,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1014 has the capability. With this option, super page will 1036 has the capability. With this option, super page will
1015 not be supported. 1037 not be supported.
1016 intremap= [X86-64, Intel-IOMMU] 1038 intremap= [X86-64, Intel-IOMMU]
1017 Format: { on (default) | off | nosid }
1018 on enable Interrupt Remapping (default) 1039 on enable Interrupt Remapping (default)
1019 off disable Interrupt Remapping 1040 off disable Interrupt Remapping
1020 nosid disable Source ID checking 1041 nosid disable Source ID checking
1042 no_x2apic_optout
1043 BIOS x2APIC opt-out request will be ignored
1021 1044
1022 inttest= [IA-64] 1045 inttest= [IA-64]
1023 1046
@@ -1181,6 +1204,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1181 [KVM,Intel] Disable FlexPriority feature (TPR shadow). 1204 [KVM,Intel] Disable FlexPriority feature (TPR shadow).
1182 Default is 1 (enabled) 1205 Default is 1 (enabled)
1183 1206
1207 kvm-intel.nested=
1208 [KVM,Intel] Enable VMX nesting (nVMX).
1209 Default is 0 (disabled)
1210
1184 kvm-intel.unrestricted_guest= 1211 kvm-intel.unrestricted_guest=
1185 [KVM,Intel] Disable unrestricted guest feature 1212 [KVM,Intel] Disable unrestricted guest feature
1186 (virtualized real and unpaged mode) on capable 1213 (virtualized real and unpaged mode) on capable
@@ -1642,6 +1669,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1642 debugging driver suspend/resume hooks). This may 1669 debugging driver suspend/resume hooks). This may
1643 not work reliably with all consoles, but is known 1670 not work reliably with all consoles, but is known
1644 to work with serial and VGA consoles. 1671 to work with serial and VGA consoles.
1672 To facilitate more flexible debugging, we also add
1673 console_suspend, a printk module parameter to control
1674 it. Users could use console_suspend (usually
1675 /sys/module/printk/parameters/console_suspend) to
1676 turn on/off it dynamically.
1645 1677
1646 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien 1678 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
1647 caches in the slab allocator. Saves per-node memory, 1679 caches in the slab allocator. Saves per-node memory,
@@ -1777,6 +1809,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1777 1809
1778 noresidual [PPC] Don't use residual data on PReP machines. 1810 noresidual [PPC] Don't use residual data on PReP machines.
1779 1811
1812 nordrand [X86] Disable the direct use of the RDRAND
1813 instruction even if it is supported by the
1814 processor. RDRAND is still available to user
1815 space applications.
1816
1780 noresume [SWSUSP] Disables resume and restores original swap 1817 noresume [SWSUSP] Disables resume and restores original swap
1781 space. 1818 space.
1782 1819
@@ -2245,6 +2282,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2245 in <PAGE_SIZE> units (needed only for swap files). 2282 in <PAGE_SIZE> units (needed only for swap files).
2246 See Documentation/power/swsusp-and-swap-files.txt 2283 See Documentation/power/swsusp-and-swap-files.txt
2247 2284
2285 resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to
2286 read the resume files
2287
2288 resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up.
2289 Useful for devices that are detected asynchronously
2290 (e.g. USB and MMC devices).
2291
2248 hibernate= [HIBERNATION] 2292 hibernate= [HIBERNATION]
2249 noresume Don't check if there's a hibernation image 2293 noresume Don't check if there's a hibernation image
2250 present during boot. 2294 present during boot.
@@ -2380,7 +2424,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2380 Format: <integer> 2424 Format: <integer>
2381 2425
2382 sonypi.*= [HW] Sony Programmable I/O Control Device driver 2426 sonypi.*= [HW] Sony Programmable I/O Control Device driver
2383 See Documentation/sonypi.txt 2427 See Documentation/laptops/sonypi.txt
2384 2428
2385 specialix= [HW,SERIAL] Specialix multi-serial port adapter 2429 specialix= [HW,SERIAL] Specialix multi-serial port adapter
2386 See Documentation/serial/specialix.txt. 2430 See Documentation/serial/specialix.txt.
@@ -2711,10 +2755,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2711 functions are at fixed addresses, they make nice 2755 functions are at fixed addresses, they make nice
2712 targets for exploits that can control RIP. 2756 targets for exploits that can control RIP.
2713 2757
2714 emulate [default] Vsyscalls turn into traps and are 2758 emulate Vsyscalls turn into traps and are emulated
2715 emulated reasonably safely. 2759 reasonably safely.
2716 2760
2717 native Vsyscalls are native syscall instructions. 2761 native [default] Vsyscalls are native syscall
2762 instructions.
2718 This is a little bit faster than trapping 2763 This is a little bit faster than trapping
2719 and makes a few dynamic recompilers work 2764 and makes a few dynamic recompilers work
2720 better than they would in emulation mode. 2765 better than they would in emulation mode.