diff options
Diffstat (limited to 'Documentation/kernel-parameters.txt')
-rw-r--r-- | Documentation/kernel-parameters.txt | 93 |
1 files changed, 76 insertions, 17 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a0c5c5f4fce6..033d4e69b43b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt | |||
@@ -315,12 +315,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
315 | CPU-intensive style benchmark, and it can vary highly in | 315 | CPU-intensive style benchmark, and it can vary highly in |
316 | a microbenchmark depending on workload and compiler. | 316 | a microbenchmark depending on workload and compiler. |
317 | 317 | ||
318 | 1: only for 32-bit processes | 318 | 32: only for 32-bit processes |
319 | 2: only for 64-bit processes | 319 | 64: only for 64-bit processes |
320 | on: enable for both 32- and 64-bit processes | 320 | on: enable for both 32- and 64-bit processes |
321 | off: disable for both 32- and 64-bit processes | 321 | off: disable for both 32- and 64-bit processes |
322 | 322 | ||
323 | amd_iommu= [HW,X86-84] | 323 | amd_iommu= [HW,X86-64] |
324 | Pass parameters to the AMD IOMMU driver in the system. | 324 | Pass parameters to the AMD IOMMU driver in the system. |
325 | Possible values are: | 325 | Possible values are: |
326 | fullflush - enable flushing of IO/TLB entries when | 326 | fullflush - enable flushing of IO/TLB entries when |
@@ -329,6 +329,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
329 | is a lot of faster | 329 | is a lot of faster |
330 | off - do not initialize any AMD IOMMU found in | 330 | off - do not initialize any AMD IOMMU found in |
331 | the system | 331 | the system |
332 | force_isolation - Force device isolation for all | ||
333 | devices. The IOMMU driver is not | ||
334 | allowed anymore to lift isolation | ||
335 | requirements as needed. This option | ||
336 | does not override iommu=pt | ||
332 | 337 | ||
333 | amijoy.map= [HW,JOY] Amiga joystick support | 338 | amijoy.map= [HW,JOY] Amiga joystick support |
334 | Map of devices attached to JOY0DAT and JOY1DAT | 339 | Map of devices attached to JOY0DAT and JOY1DAT |
@@ -623,6 +628,25 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
623 | no_debug_objects | 628 | no_debug_objects |
624 | [KNL] Disable object debugging | 629 | [KNL] Disable object debugging |
625 | 630 | ||
631 | debug_guardpage_minorder= | ||
632 | [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this | ||
633 | parameter allows control of the order of pages that will | ||
634 | be intentionally kept free (and hence protected) by the | ||
635 | buddy allocator. Bigger value increase the probability | ||
636 | of catching random memory corruption, but reduce the | ||
637 | amount of memory for normal system use. The maximum | ||
638 | possible value is MAX_ORDER/2. Setting this parameter | ||
639 | to 1 or 2 should be enough to identify most random | ||
640 | memory corruption problems caused by bugs in kernel or | ||
641 | driver code when a CPU writes to (or reads from) a | ||
642 | random memory location. Note that there exists a class | ||
643 | of memory corruptions problems caused by buggy H/W or | ||
644 | F/W or by drivers badly programing DMA (basically when | ||
645 | memory is written at bus level and the CPU MMU is | ||
646 | bypassed) which are not detectable by | ||
647 | CONFIG_DEBUG_PAGEALLOC, hence this option will not help | ||
648 | tracking down these problems. | ||
649 | |||
626 | debugpat [X86] Enable PAT debugging | 650 | debugpat [X86] Enable PAT debugging |
627 | 651 | ||
628 | decnet.addr= [HW,NET] | 652 | decnet.addr= [HW,NET] |
@@ -1035,6 +1059,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
1035 | By default, super page will be supported if Intel IOMMU | 1059 | By default, super page will be supported if Intel IOMMU |
1036 | has the capability. With this option, super page will | 1060 | has the capability. With this option, super page will |
1037 | not be supported. | 1061 | not be supported. |
1062 | |||
1063 | intel_idle.max_cstate= [KNL,HW,ACPI,X86] | ||
1064 | 0 disables intel_idle and fall back on acpi_idle. | ||
1065 | 1 to 6 specify maximum depth of C-state. | ||
1066 | |||
1038 | intremap= [X86-64, Intel-IOMMU] | 1067 | intremap= [X86-64, Intel-IOMMU] |
1039 | on enable Interrupt Remapping (default) | 1068 | on enable Interrupt Remapping (default) |
1040 | off disable Interrupt Remapping | 1069 | off disable Interrupt Remapping |
@@ -1059,7 +1088,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
1059 | nomerge | 1088 | nomerge |
1060 | forcesac | 1089 | forcesac |
1061 | soft | 1090 | soft |
1062 | pt [x86, IA-64] | 1091 | pt [x86, IA-64] |
1092 | group_mf [x86, IA-64] | ||
1093 | |||
1063 | 1094 | ||
1064 | io7= [HW] IO7 for Marvel based alpha systems | 1095 | io7= [HW] IO7 for Marvel based alpha systems |
1065 | See comment before marvel_specify_io7 in | 1096 | See comment before marvel_specify_io7 in |
@@ -1178,9 +1209,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
1178 | kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. | 1209 | kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. |
1179 | Default is 0 (don't ignore, but inject #GP) | 1210 | Default is 0 (don't ignore, but inject #GP) |
1180 | 1211 | ||
1181 | kvm.oos_shadow= [KVM] Disable out-of-sync shadow paging. | ||
1182 | Default is 1 (enabled) | ||
1183 | |||
1184 | kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit | 1212 | kvm.mmu_audit= [KVM] This is a R/W parameter which allows audit |
1185 | KVM MMU at runtime. | 1213 | KVM MMU at runtime. |
1186 | Default is 0 (off) | 1214 | Default is 0 (off) |
@@ -1630,12 +1658,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
1630 | The default is to return 64-bit inode numbers. | 1658 | The default is to return 64-bit inode numbers. |
1631 | 1659 | ||
1632 | nfs.nfs4_disable_idmapping= | 1660 | nfs.nfs4_disable_idmapping= |
1633 | [NFSv4] When set, this option disables the NFSv4 | 1661 | [NFSv4] When set to the default of '1', this option |
1634 | idmapper on the client, but only if the mount | 1662 | ensures that both the RPC level authentication |
1635 | is using the 'sec=sys' security flavour. This may | 1663 | scheme and the NFS level operations agree to use |
1636 | make migration from legacy NFSv2/v3 systems easier | 1664 | numeric uids/gids if the mount is using the |
1637 | provided that the server has the appropriate support. | 1665 | 'sec=sys' security flavour. In effect it is |
1638 | The default is to always enable NFSv4 idmapping. | 1666 | disabling idmapping, which can make migration from |
1667 | legacy NFSv2/v3 systems to NFSv4 easier. | ||
1668 | Servers that do not support this mode of operation | ||
1669 | will be autodetected by the client, and it will fall | ||
1670 | back to using the idmapper. | ||
1671 | To turn off this behaviour, set the value to '0'. | ||
1639 | 1672 | ||
1640 | nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take | 1673 | nmi_debug= [KNL,AVR32,SH] Specify one or more actions to take |
1641 | when a NMI is triggered. | 1674 | when a NMI is triggered. |
@@ -1796,6 +1829,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
1796 | nomfgpt [X86-32] Disable Multi-Function General Purpose | 1829 | nomfgpt [X86-32] Disable Multi-Function General Purpose |
1797 | Timer usage (for AMD Geode machines). | 1830 | Timer usage (for AMD Geode machines). |
1798 | 1831 | ||
1832 | nonmi_ipi [X86] Disable using NMI IPIs during panic/reboot to | ||
1833 | shutdown the other cpus. Instead use the REBOOT_VECTOR | ||
1834 | irq. | ||
1835 | |||
1799 | nopat [X86] Disable PAT (page attribute table extension of | 1836 | nopat [X86] Disable PAT (page attribute table extension of |
1800 | pagetables) support. | 1837 | pagetables) support. |
1801 | 1838 | ||
@@ -1885,6 +1922,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
1885 | arch_perfmon: [X86] Force use of architectural | 1922 | arch_perfmon: [X86] Force use of architectural |
1886 | perfmon on Intel CPUs instead of the | 1923 | perfmon on Intel CPUs instead of the |
1887 | CPU specific event set. | 1924 | CPU specific event set. |
1925 | timer: [X86] Force use of architectural NMI | ||
1926 | timer mode (see also oprofile.timer | ||
1927 | for generic hr timer mode) | ||
1928 | [s390] Force legacy basic mode sampling | ||
1929 | (report cpu_type "timer") | ||
1888 | 1930 | ||
1889 | oops=panic Always panic on oopses. Default is to just kill the | 1931 | oops=panic Always panic on oopses. Default is to just kill the |
1890 | process, but there is a small probability of | 1932 | process, but there is a small probability of |
@@ -2362,6 +2404,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
2362 | 2404 | ||
2363 | slram= [HW,MTD] | 2405 | slram= [HW,MTD] |
2364 | 2406 | ||
2407 | slab_max_order= [MM, SLAB] | ||
2408 | Determines the maximum allowed order for slabs. | ||
2409 | A high setting may cause OOMs due to memory | ||
2410 | fragmentation. Defaults to 1 for systems with | ||
2411 | more than 32MB of RAM, 0 otherwise. | ||
2412 | |||
2365 | slub_debug[=options[,slabs]] [MM, SLUB] | 2413 | slub_debug[=options[,slabs]] [MM, SLUB] |
2366 | Enabling slub_debug allows one to determine the | 2414 | Enabling slub_debug allows one to determine the |
2367 | culprit if slab objects become corrupted. Enabling | 2415 | culprit if slab objects become corrupted. Enabling |
@@ -2432,6 +2480,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
2432 | stacktrace [FTRACE] | 2480 | stacktrace [FTRACE] |
2433 | Enabled the stack tracer on boot up. | 2481 | Enabled the stack tracer on boot up. |
2434 | 2482 | ||
2483 | stacktrace_filter=[function-list] | ||
2484 | [FTRACE] Limit the functions that the stack tracer | ||
2485 | will trace at boot up. function-list is a comma separated | ||
2486 | list of functions. This list can be changed at run | ||
2487 | time by the stack_trace_filter file in the debugfs | ||
2488 | tracing directory. Note, this enables stack tracing | ||
2489 | and the stacktrace above is not needed. | ||
2490 | |||
2435 | sti= [PARISC,HW] | 2491 | sti= [PARISC,HW] |
2436 | Format: <num> | 2492 | Format: <num> |
2437 | Set the STI (builtin display/keyboard on the HP-PARISC | 2493 | Set the STI (builtin display/keyboard on the HP-PARISC |
@@ -2632,6 +2688,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
2632 | [USB] Start with the old device initialization | 2688 | [USB] Start with the old device initialization |
2633 | scheme (default 0 = off). | 2689 | scheme (default 0 = off). |
2634 | 2690 | ||
2691 | usbcore.usbfs_memory_mb= | ||
2692 | [USB] Memory limit (in MB) for buffers allocated by | ||
2693 | usbfs (default = 16, 0 = max = 2047). | ||
2694 | |||
2635 | usbcore.use_both_schemes= | 2695 | usbcore.use_both_schemes= |
2636 | [USB] Try the other device initialization scheme | 2696 | [USB] Try the other device initialization scheme |
2637 | if the first one fails (default 1 = enabled). | 2697 | if the first one fails (default 1 = enabled). |
@@ -2750,11 +2810,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. | |||
2750 | functions are at fixed addresses, they make nice | 2810 | functions are at fixed addresses, they make nice |
2751 | targets for exploits that can control RIP. | 2811 | targets for exploits that can control RIP. |
2752 | 2812 | ||
2753 | emulate Vsyscalls turn into traps and are emulated | 2813 | emulate [default] Vsyscalls turn into traps and are |
2754 | reasonably safely. | 2814 | emulated reasonably safely. |
2755 | 2815 | ||
2756 | native [default] Vsyscalls are native syscall | 2816 | native Vsyscalls are native syscall instructions. |
2757 | instructions. | ||
2758 | This is a little bit faster than trapping | 2817 | This is a little bit faster than trapping |
2759 | and makes a few dynamic recompilers work | 2818 | and makes a few dynamic recompilers work |
2760 | better than they would in emulation mode. | 2819 | better than they would in emulation mode. |