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-rw-r--r--Documentation/kernel-parameters.txt93
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.