diff options
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 67 |
1 files changed, 46 insertions, 21 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index ff5018b39ed0..bdc1f33fd3d1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -724,7 +724,7 @@ memory region [offset, offset + size] for that kernel image. If '@offset' is omitted, then a suitable offset is selected automatically. - [KNL, x86_64] select a region under 4G first, and + [KNL, X86-64] Select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. See Documentation/admin-guide/kdump/kdump.rst for further details. @@ -737,14 +737,14 @@ Documentation/admin-guide/kdump/kdump.rst for an example. crashkernel=size[KMG],high - [KNL, x86_64] range could be above 4G. Allow kernel + [KNL, X86-64] range could be above 4G. Allow kernel to allocate physical memory region from top, so could be above 4G if system have more than 4G ram installed. Otherwise memory region will be allocated below 4G, if available. It will be ignored if crashkernel=X is specified. crashkernel=size[KMG],low - [KNL, x86_64] range under 4G. When crashkernel=X,high + [KNL, X86-64] range under 4G. When crashkernel=X,high is passed, kernel could allocate physical memory region above 4G, that cause second kernel crash on system that require some amount of low memory, e.g. swiotlb @@ -832,6 +832,21 @@ useful to also enable the page_owner functionality. on: enable the feature + debugfs= [KNL] This parameter enables what is exposed to userspace + and debugfs internal clients. + Format: { on, no-mount, off } + on: All functions are enabled. + no-mount: + Filesystem is not registered but kernel clients can + access APIs and a crashkernel can be used to read + its content. There is nothing to mount. + off: Filesystem is not registered and clients + get a -EPERM as result when trying to register files + or directories within debugfs. + This is equivalent of the runtime functionality if + debugfs was not enabled in the kernel at all. + Default value is set in build-time with a kernel configuration. + debugpat [X86] Enable PAT debugging decnet.addr= [HW,NET] @@ -901,6 +916,10 @@ disable_radix [PPC] Disable RADIX MMU mode on POWER9 + radix_hcall_invalidate=on [PPC/PSERIES] + Disable RADIX GTSE feature and use hcall for TLB + invalidate. + disable_tlbie [PPC] Disable TLBIE instruction. Currently does not work with KVM, with HASH MMU, or with coherent accelerators. @@ -1408,7 +1427,7 @@ gamma= [HW,DRM] - gart_fix_e820= [X86_64] disable the fix e820 for K8 GART + gart_fix_e820= [X86-64] disable the fix e820 for K8 GART Format: off | on default: on @@ -1795,7 +1814,7 @@ Format: 0 | 1 Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON. - init_pkru= [x86] Specify the default memory protection keys rights + init_pkru= [X86] Specify the default memory protection keys rights register contents for all processes. 0x55555554 by default (disallow access to all but pkey 0). Can override in debugfs after boot. @@ -1803,7 +1822,7 @@ inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver Format: <irq> - int_pln_enable [x86] Enable power limit notification interrupt + int_pln_enable [X86] Enable power limit notification interrupt integrity_audit=[IMA] Format: { "0" | "1" } @@ -1821,7 +1840,7 @@ bypassed by not enabling DMAR with this option. In this case, gfx device will use physical address for DMA. - forcedac [x86_64] + forcedac [X86-64] With this option iommu will not optimize to look for io virtual address below 32-bit forcing dual address cycle on pci bus for cards supporting greater @@ -1906,7 +1925,7 @@ strict regions from userspace. relaxed - iommu= [x86] + iommu= [X86] off force noforce @@ -1916,8 +1935,8 @@ merge nomerge soft - pt [x86] - nopt [x86] + pt [X86] + nopt [X86] nobypass [PPC/POWERNV] Disable IOMMU bypass, using IOMMU for PCI devices. @@ -2060,21 +2079,21 @@ iucv= [HW,NET] - ivrs_ioapic [HW,X86_64] + ivrs_ioapic [HW,X86-64] Provide an override to the IOAPIC-ID<->DEVICE-ID mapping provided in the IVRS ACPI table. For example, to map IOAPIC-ID decimal 10 to PCI device 00:14.0 write the parameter as: ivrs_ioapic[10]=00:14.0 - ivrs_hpet [HW,X86_64] + ivrs_hpet [HW,X86-64] Provide an override to the HPET-ID<->DEVICE-ID mapping provided in the IVRS ACPI table. For example, to map HPET-ID decimal 0 to PCI device 00:14.0 write the parameter as: ivrs_hpet[0]=00:14.0 - ivrs_acpihid [HW,X86_64] + ivrs_acpihid [HW,X86-64] Provide an override to the ACPI-HID:UID<->DEVICE-ID mapping provided in the IVRS ACPI table. For example, to map UART-HID:UID AMD0020:0 to @@ -2351,7 +2370,7 @@ lapic [X86-32,APIC] Enable the local APIC even if BIOS disabled it. - lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline + lapic= [X86,APIC] "notscdeadline" Do not use TSC deadline value for LAPIC timer one-shot implementation. Default back to the programmable timer unit in the LAPIC. @@ -3169,12 +3188,12 @@ register save and restore. The kernel will only save legacy floating-point registers on task switch. - nohugeiomap [KNL,x86,PPC] Disable kernel huge I/O mappings. + nohugeiomap [KNL,X86,PPC] Disable kernel huge I/O mappings. nosmt [KNL,S390] Disable symmetric multithreading (SMT). Equivalent to smt=1. - [KNL,x86] Disable symmetric multithreading (SMT). + [KNL,X86] Disable symmetric multithreading (SMT). nosmt=force: Force disable SMT, cannot be undone via the sysfs control file. @@ -3936,7 +3955,7 @@ pt. [PARIDE] See Documentation/admin-guide/blockdev/paride.rst. - pti= [X86_64] Control Page Table Isolation of user and + pti= [X86-64] Control Page Table Isolation of user and kernel address spaces. Disabling this feature removes hardening, but improves performance of system calls and interrupts. @@ -3948,7 +3967,7 @@ Not specifying this option is equivalent to pti=auto. - nopti [X86_64] + nopti [X86-64] Equivalent to pti=off pty.legacy_count= @@ -4674,7 +4693,7 @@ fragmentation. Defaults to 1 for systems with more than 32MB of RAM, 0 otherwise. - slub_debug[=options[,slabs]] [MM, SLUB] + slub_debug[=options[,slabs][;[options[,slabs]]...] [MM, SLUB] Enabling slub_debug allows one to determine the culprit if slab objects become corrupted. Enabling slub_debug can create guard zones around objects and @@ -5789,8 +5808,9 @@ panic() code such as dumping handler. xen_nopvspin [X86,XEN] - Disables the ticketlock slowpath using Xen PV - optimizations. + Disables the qspinlock slowpath using Xen PV optimizations. + This parameter is obsoleted by "nopvspin" parameter, which + has equivalent effect for XEN platform. xen_nopv [X86] Disables the PV optimizations forcing the HVM guest to @@ -5816,6 +5836,11 @@ as generic guest with no PV drivers. Currently support XEN HVM, KVM, HYPER_V and VMWARE guest. + nopvspin [X86,XEN,KVM] + Disables the qspinlock slow path using PV optimizations + which allow the hypervisor to 'idle' the guest on lock + contention. + xirc2ps_cs= [NET,PCMCIA] Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] |