Lines Matching +full:locality +full:- +full:specific
37 Documentation/arch/m68k/kernel-options.rst.
46 PARISC The PA-RISC architecture is enabled.
61 the Documentation/scsi/ sub-directory.
81 X86-32 X86-32, aka i386 architecture is enabled.
82 X86-64 X86-64 architecture is enabled.
83 X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64)
92 KNL Is a kernel start-up parameter.
112 force -- enable ACPI if default was off
113 on -- enable ACPI but allow fallback to DT [arm64,riscv64]
114 off -- disable ACPI if default was on
115 noirq -- do not use ACPI for IRQ routing
116 strict -- Be less tolerant of platforms that are not
118 rsdt -- prefer RSDT over (default) XSDT
119 copy_dsdt -- copy DSDT to memory
120 nocmcff -- Disable firmware first mode for corrected
124 nospcr -- disable console in ACPI SPCR table as
126 spcr -- enable console in ACPI SPCR table as
143 If set to vendor, prefer vendor-specific driver
175 Documentation/firmware-guide/acpi/debug.rst for more information about
241 Format: <byte> or <bitmap-list>
244 Disable auto-serialization of AML methods
247 auto-serialization feature.
265 Ignore the ACPI-based watchdog interface (WDAT) and let
286 acpi_osi=! # disable all built-in OS vendor
288 acpi_osi=!! # enable all built-in OS vendor
293 multiple 'acpi_osi="string1"' to support specific OS
318 multiple 'acpi_osi="string1"' to support specific
350 For broken nForce2 BIOS resulting in XT-PIC timer.
359 as soon as the kernel's real-mode entry point is called.
397 See Documentation/sound/alsa-configuration.rst
404 align_va_addr= [X86-64]
409 CPU-intensive style benchmark, and it can vary highly in
412 32: only for 32-bit processes
413 64: only for 64-bit processes
414 on: enable for both 32- and 64-bit processes
415 off: disable for both 32- and 64-bit processes
425 Allow execve() of 32-bit applications and setting of the
427 subset of the CPUs support 32-bit EL0. When this
428 parameter is present, the set of CPUs supporting 32-bit
430 and hot-unplug operations may be restricted.
432 See Documentation/arch/arm64/asymmetric-32bit.rst for more
435 amd_iommu= [HW,X86-64]
438 fullflush - Deprecated, equivalent to iommu.strict=1
439 off - do not initialize any AMD IOMMU found in
441 force_isolation - Force device isolation for all
446 force_enable - Force enable the IOMMU on platforms known
449 pgtbl_v1 - Use v1 page table for DMA-API (Default).
450 pgtbl_v2 - Use v2 page table for DMA-API.
451 irtcachedis - Disable Interrupt Remapping Table (IRT) caching.
452 nohugepages - Limit page-sizes used for v1 page-tables
454 v2_pgsizes_only - Limit page-sizes used for v1 page-tables
458 amd_iommu_dump= [HW,X86-64]
464 amd_iommu_intr= [HW,X86-64]
467 legacy - Use legacy interrupt remapping mode.
468 vapic - Use virtual APIC mode, which allows IOMMU
470 This mode requires kvm-amd.avic=1.
499 Disable amd-pstate preferred core.
504 Disable amd-pstate dynamic EPP.
506 Enable amd-pstate dynamic EPP.
519 Power management functions (SPARCstation-4/5 + deriv.)
521 Disable APC CPU standby support. SPARCstation-Fox does
522 not play well with APC CPU idle - disable it if you have
525 apic [APIC,X86-64] Use IO-APIC. Default.
531 when initialising the APIC and IO-APIC components.
555 0 -- disable.
556 1 -- enable.
607 audit= [KNL] Enable the audit sub-system
609 0 | off - kernel audit is disabled and can not be
611 unset - kernel audit is initialized but disabled and
613 1 | on - kernel audit is initialized and partially
626 0 - Disable the BAU.
627 1 - Enable the BAU.
628 unset - Disable the BAU.
650 See Documentation/block/cmdline-partition.rst
664 See Documentation/admin-guide/bootconfig.rst
669 bttv.pll= See Documentation/admin-guide/media/bttv.rst
678 cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
690 ca_keys= [KEYS] This parameter identifies a specific key(s) on
697 inclusive. See arch/mips/include/asm/pgtable-bits.h
698 for platform specific values (SB1, Loongson3 and
704 cfi= [X86-64] Set Control Flow Integrity checking features
715 norand: Do not re-randomize CFI hashes.
725 - foo isn't auto-mounted if you mount all cgroups in
727 - foo isn't visible as an individually mountable
729 - if foo is an optional feature then the feature is
735 Specifying "pressure" disables per-cgroup pressure
752 semi-legacy software can check this file to decide
761 nosocket -- Disable socket memory accounting.
762 nokmem -- Disable kernel memory accounting.
763 nobpf -- Disable BPF memory accounting.
767 double-frees, use-after-frees, and other sources of
776 0 -- check protection applied by kernel (includes
778 1 -- check protection requested by application.
793 force such clocks to be always-on nor does it reserve
797 information, see Documentation/driver-api/clk.rst.
799 clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
816 [X86-32] pit,hpet,tsc;
823 [X86-64] hpet,tsc
829 architected timer so that code using WFE-based polling
843 clocksource-wdtest.holdoff= [KNL]
849 cma=nn[MG]@[start[MG][-end[MG]]]
860 Sets the size of kernel per-numa memory area for
862 per-numa CMA altogether. And If this option is not
864 With per-numa CMA enabled, DMA users on node nid will
921 See Documentation/admin-guide/serial-console.rst for more
936 $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
937 /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
950 Start an early, polled-mode console on the 8250/16550
953 MMIO inter-register address stride is either 8-bit
954 (mmio), 16-bit (mmio16), or 32-bit (mmio32).
958 the h/w is not re-initialized.
985 syscall, or to executing "dmesg -S --raw" or to reading
1009 disable the cpuidle sub-system
1015 disable the cpufreq sub-system
1023 [X86,EARLY] Delay for N microsec between assert and de-assert
1044 like Hyper-V, PowerPC (fadump) and AMD SEV-SNP.
1052 [KNL, X86-64, ARM64, RISCV, LoongArch] Select a region
1055 See Documentation/admin-guide/kdump/kdump.rst for further details.
1060 start-[end] where start and end are both
1062 Documentation/admin-guide/kdump/kdump.rst for an example.
1065 [KNL, X86-64, ARM64, RISCV, LoongArch] range could be
1073 [KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G.
1079 for 32-bit devices won't run out. Kernel would try to allocate
1082 --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB)
1083 --> arm64: 128MiB
1084 --> riscv: 128MiB
1085 --> loongarch: 128MiB
1115 [KNL] Disable crypto self-tests
1123 csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU
1138 See also Documentation/input/devices/joystick-parport.rst
1151 [KNL] verbose locking self-tests
1154 self-tests.
1156 (no extra messages), setting it to -1 (all bits set)
1157 will print _a_lot_ more information - normally only
1195 get a -EPERM as result when trying to register files
1199 Default value is set in build-time with a kernel configuration.
1211 Documentation/admin-guide/mm/hugetlbpage.rst.
1217 probe. Only specific dependencies (subsystems or
1226 delayacct [KNL] Enable per-task delay accounting
1312 entries for DMA-API debugging code. One entry is
1313 required per DMA-API allocation. Use this if the
1314 DMA-API debugging code disables itself because the
1318 With this option the DMA-API debugging driver
1342 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
1345 [KNL] When set to 1, leave the dm-verity keyring
1374 Control how the dt_cpu_ftrs device-tree binding is
1384 what data is available or for reverse-engineering.
1389 Documentation/admin-guide/dynamic-debug-howto.rst
1400 determined by stdout-path property in device tree's
1405 Start an early, polled-mode console on a Cadence
1416 Start an early, polled-mode console on the 8250/16550
1418 MMIO inter-register address stride is either 8-bit
1419 (mmio) or 32-bit (mmio32 or mmio32be).
1429 Start an early, polled-mode console on a pl011 serial
1433 the driver will use only 32-bit accessors to read/write
1442 Start an early, polled-mode console on a meson serial
1448 Start an early, polled-mode console on an msm serial
1454 Start an early, polled-mode console on an msm serial
1460 Start an early, polled-mode console on a serial port
1466 Start an early, polled-mode console on a serial port
1472 Use RISC-V SBI (Supervisor Binary Interface) for early
1490 Start an early, polled-mode console on a lantiq serial
1504 Start an early, polled-mode, output-only console on the
1509 Start an early, polled-mode console on the
1515 Start an early, polled-mode console on a Qualcomm
1523 coherent non-x86 systems that use system memory for
1606 nosoftreserve: The EFI_MEMORY_SP (Specific Purpose)
1626 Documentation/admin-guide/acpi/ssdt-overlays.rst for details.
1647 See Documentation/admin-guide/kdump/kdump.rst for details.
1663 0 -- permissive (log only, no denials).
1664 1 -- enforcing (deny and log).
1697 See also Documentation/fault-injection/.
1701 See Documentation/admin-guide/sysctl/net.rst for
1705 See Documentation/admin-guide/blockdev/floppy.rst.
1707 forcepae [X86-32]
1714 fred= [X86-64]
1748 the oops, or the specific instance will be dumped if
1765 ftrace_filter=[function-list]
1767 tracer at boot up. function-list is a comma-separated
1772 ftrace_notrace=[function-list]
1774 function-list. This list can be changed at run time
1778 ftrace_graph_filter=[function-list]
1781 function-list is a comma-separated list of functions
1785 ftrace_graph_notrace=[function-list]
1787 function-list. This list is a comma-separated list of
1807 off -- Don't create device links from firmware info.
1808 permissive -- Create device links from firmware info
1811 on -- Create device links from firmware info and use it
1813 rpm -- Like "on", but also use to order runtime PM.
1826 strict -- Default. Continue waiting on consumers to
1828 timeout -- Give up waiting on consumers and call
1838 See also Documentation/input/devices/joystick-parport.rst
1842 gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART
1868 gcov_persist= [GCOV] When non-zero (default), profiling data for
1878 gpio-mockup.gpio_mockup_ranges
1881 gpio-mockup.gpio_mockup_named_lines
1913 against bounds-checking flaws in the kernel's
1921 [KNL] Should the hard-lockup detector generate
1937 auto - Hash pointers unless slab_debug is enabled.
1938 always - Always hash pointers (even if slab_debug is
1940 never - Never hash pointers. This option should only
1951 for 64-bit NUMA, off otherwise.
1959 corresponding firmware-first mode error processing
1969 during restoration read-only).
2023 hpet= [X86-32,HPET] option to control HPET usage
2040 number of pages to allocate per-node can be specified.
2041 See also Documentation/admin-guide/mm/hugetlbpage.rst.
2048 allocate huge pages of a specific size at boot. The
2052 Documentation/admin-guide/mm/hugetlbpage.rst.
2062 Note that this parameter only applies to non-gigantic huge pages.
2071 When using node format, this applies to each per-node size.
2076 boot-time allocation of gigantic hugepages is skipped.
2109 When set to a non-zero value, a kernel panic will be triggered if
2117 CONFIG_BOOTPARAM_HUNG_TASK_PANIC build-time option. The value
2123 hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs.
2138 i2c_bus= [HW] Override the default board specific I2C bus speed
2145 Set device-properties for ACPI-enumerated I2C-attached
2146 touchscreen, to e.g. fix coordinates of upside-down
2154 Omit "=<val>" entirely Set a boolean device-property
2155 Unsigned number Set a u32 device-property
2156 Anything else Set a string device-property
2159 i2c_touchscreen_props=GDIX1001:touchscreen-inverted-x:
2160 touchscreen-inverted-y
2162 i2c_touchscreen_props=MSSL1680:touchscreen-size-x=1920:
2163 touchscreen-size-y=1080:touchscreen-inverted-y:
2164 firmware-name=gsl1680-vendor-model.fw:silead,home-button
2169 (disabled by default, and as a pre-condition
2171 i8042.direct [HW] Put keyboard port into non-translated mode
2185 suspend-to-ram transitions, only during s2r
2209 -1 -- never invert brightness
2210 0 -- machine default
2211 1 -- force brightness inversion
2213 ia32_emulation= [X86-64]
2215 When true, allows loading 32-bit programs and executing 32-bit
2237 idle=nomwait: Disable mwait for CPU C-states
2265 legacy only accept legacy-NaN binaries, if supported
2267 2008 only accept 2008-NaN binaries, if supported
2278 'relaxed' straps the emulator for both legacy-NaN and
2279 2008-NaN, whereas 'strict' enables legacy-NaN only on
2288 Ignore loglevel setting - this will print /all/
2361 Formats: { "ima" | "ima-ng" | "ima-ngv2" | "ima-sig" |
2362 "ima-sigv2" }
2363 Default: "ima-ng"
2384 stuff: Deploy RSB-fill mitigation when retpoline is
2389 Documentation/admin-guide/hw-vuln/indirect-target-selection.rst
2400 initcall_blacklist= [KNL] Do not execute a comma-separated list of
2401 initcall functions. Useful for debugging built-in
2446 0 -- basic integrity auditing messages. (Default)
2447 1 -- additional integrity auditing messages.
2475 could harm performance of some high-throughput
2484 1 to 9 specify maximum depth of C-state.
2493 algorithms for p-state selection. There are two
2494 P-state selection algorithms provided by
2497 on whether or not the hardware managed P-states
2504 used along with the hardware-managed P-states (HWP)
2508 in favor of acpi-cpufreq. Forcing the intel_pstate driver
2509 instead of acpi-cpufreq may disable platform features, such
2511 P-States information being indicated to OSPM and therefore
2514 or on platforms that use pcc-cpufreq instead of acpi-cpufreq.
2527 Allow per-logical-CPU P-State performance control limits using
2530 Do not enable capacity-aware scheduling (CAS) on
2533 intremap= [X86-64,Intel-IOMMU,EARLY]
2538 BIOS x2APIC opt-out request will be ignored
2562 Do scatter-gather (SG) merging. Implies "force"
2566 Don't do scatter-gather (SG) merging.
2569 Do scatter-gather (SG) merging. Implies "force"
2595 AMD Gart HW IOMMU-specific options: (CONFIG_GART_IOMMU)
2601 Overwrite iommu off workarounds for specific chipsets
2604 Overwrite iommu off workarounds for specific chipsets
2629 0 - Try to allocate a 32-bit DMA address first, before
2631 1 - Allocate directly from the full usable range,
2633 greater than 32-bit addressing.
2637 0 - Lazy mode.
2643 1 - Strict mode.
2646 unset - Use value of CONFIG_IOMMU_DEFAULT_DMA_{LAZY,STRICT}.
2648 legacy driver-specific options takes precedence.
2653 0 - Use IOMMU translation for DMA.
2654 1 - Bypass the IOMMU for DMA.
2655 unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
2663 0 - Sanitizer disabled.
2664 1 - Sanitizer enabled, expect runtime overhead.
2666 io7= [HW] IO7 for Marvel-based Alpha systems
2681 See Documentation/admin-guide/nfs/nfsroot.rst.
2717 Enables support for pseudo-NMIs in the kernel. This
2722 [RISC-V,EARLY]
2724 as IPIs. Intended for system where IMSIC is trap-n-emulated,
2736 long-running IRQs in the system.
2748 Format: [flag-list,]<cpu-list>
2775 Documentation/admin-guide/cpu-isolation.rst.
2780 "number of CPUs in system - 1".
2806 The format of <cpu-list> is described above.
2810 ivrs_ioapic [HW,X86-64]
2811 Provide an override to the IOAPIC-ID<->DEVICE-ID
2815 For example, to map IOAPIC-ID decimal 10 to
2821 * To map IOAPIC-ID decimal 10 to PCI device 00:14.0
2824 * To map IOAPIC-ID decimal 10 to PCI segment 0x1 and
2828 ivrs_hpet [HW,X86-64]
2829 Provide an override to the HPET-ID<->DEVICE-ID
2833 For example, to map HPET-ID decimal 10 to
2839 * To map HPET-ID decimal 0 to PCI device 00:14.0
2842 * To map HPET-ID decimal 10 to PCI segment 0x1 and
2846 ivrs_acpihid [HW,X86-64]
2847 Provide an override to the ACPI-HID:UID<->DEVICE-ID
2851 For example, to map UART-HID:UID AMD0020:0 to
2857 * To map UART-HID:UID AMD0020:0 to PCI segment is 0,
2860 * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and
2884 the kernel for non-movable allocations. The requested
2894 subsystem. Note that allocations like PTEs-from-HighMem
2902 for non-movable allocations and remaining memory is used
2913 [MM,KFENCE] Whether to check all KFENCE-managed objects'
2920 allocations. This avoids forcing CPU wake-ups if the
2928 report - print the error report and continue (default).
2929 oops - print the error report and oops.
2930 panic - print the error report and panic.
2935 0 - Disable KFENCE.
2936 >0 - Enabled KFENCE with given sample interval.
2954 gdb or control-c on the dbgp connection. When
2955 not using this parameter you use sysrq-g to break into
2960 or a supported polling keyboard driver (non-usb).
2989 "0" | "off" | "n" - kexec handover is disabled
2990 "1" | "on" | "y" - kexec handover is enabled
2996 ranges that can only be used for non-kernel
3007 parameter defines the size of additional per-node
3012 Configure the RouterBoard 532 series on-chip
3015 kmemleak= [KNL,EARLY] Boot-time kmemleak enable/disable
3021 kprobe_event=[probe-list]
3023 The probe-list is a semicolon delimited list of probe
3053 execution by eliminating the write-protection faults
3077 can be overridden on a per-VM basis via
3085 with an in-kernel local APIC, e.g. to deliver PMIs to
3086 the guest. Running without an in-kernel local APIC is
3100 virtualization on-demand when creating and destroying
3108 is that doing so may interfere with using out-of-tree
3135 back to huge pages. If the value is a non-zero N, KVM will
3140 kvm-{amd,intel}.enable_mediated_pmu=[KVM,AMD,INTEL]
3142 instead of the default perf-based virtual PMU (if
3146 With a perf-based vPMU, KVM operates as a user of perf,
3148 KVM-created perf events are managed by perf as regular
3149 (guest-only) events, e.g. are scheduled in/out, contend
3150 for hardware resources, etc. Using a perf-based vPMU
3151 allows guest and host usage of the PMU to co-exist, but
3152 incurs non-trivial overhead and can result in silently
3164 to profile KVM guests and adds latency to most VM-Exits
3169 kvm-amd.nested= [KVM,AMD] Control nested virtualization feature in
3172 kvm-amd.npt= [KVM,AMD] Control KVM's use of Nested Page Tables,
3173 a.k.a. Two-Dimensional Page Tables. Default is 1
3177 kvm-amd.ciphertext_hiding_asids=
3182 If ciphertext hiding is enabled, the joint SEV-ES and
3183 SEV-SNP ASID space is partitioned into separate SEV-ES
3184 and SEV-SNP ASID ranges, with the SEV-SNP range being
3185 [1..max_snp_asid] and the SEV-ES range being
3189 A non-zero value enables SEV-SNP ciphertext hiding and
3190 adjusts the ASID ranges for SEV-ES and SEV-SNP guests.
3191 KVM caps the number of SEV-SNP ASIDs at the maximum
3192 possible value, e.g. specifying -1u will assign all
3193 joint SEV-ES and SEV-SNP ASIDs to SEV-SNP. Note,
3194 assigning all joint ASIDs to SEV-SNP, i.e. configuring
3195 max_snp_asid == min_sev_asid-1, will effectively make
3196 SEV-ES unusable.
3198 kvm-arm.mode=
3204 nvhe: Standard nVHE-based mode, without support for
3211 nested: VHE-based mode with support for nested
3219 command-line.
3223 kvm-arm.vgic_v3_group0_trap=
3224 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-0
3227 kvm-arm.vgic_v3_group1_trap=
3228 [KVM,ARM,EARLY] Trap guest accesses to GICv3 group-1
3231 kvm-arm.vgic_v3_common_trap=
3235 kvm-arm.vgic_v4_enable=
3239 kvm-arm.wfe_trap_policy=
3248 kvm-arm.wfi_trap_policy=
3265 kvm-intel.ept= [KVM,Intel] Control KVM's use of Extended Page Tables,
3266 a.k.a. Two-Dimensional Page Tables. Default is 1
3270 kvm-intel.emulate_invalid_guest_state=
3272 state. Ignored if kvm-intel.enable_unrestricted_guest=1,
3278 kvm-intel.flexpriority=
3283 kvm-intel.nested=
3287 kvm-intel.unrestricted_guest=
3293 kvm-intel.vmentry_l1d_flush=[KVM,Intel] Mitigation for L1 Terminal Fault
3294 CVE-2018-3620.
3303 Default is cond (do L1 cache flush in specific instances)
3305 kvm-intel.vpid= [KVM,Intel] Control KVM's use of Virtual Processor
3325 on - enable the interface for the mitigation
3390 For details see: Documentation/admin-guide/hw-vuln/l1tf.rst
3396 lapic [X86-32,APIC,EARLY] Enable the local APIC even if BIOS
3400 value for LAPIC timer one-shot implementation. Default
3423 libata.force= [LIBATA] Force configurations. The format is a comma-
3435 first fan-out link behind PMP device. It does not
3449 * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
3456 * rstonce: only attempt one reset during hot-unplug
3492 number of 512-byte sectors, to the value specified in
3494 a non-zero positive integer.
3504 * external: Mark port as external (hotplug-capable).
3561 Specify the number of self-propagating call_rcu()
3569 occasional long-duration lock hold time. Defaults
3580 Set the number of locking read-acquisition kthreads.
3585 Set the number of locking write-acquisition kthreads.
3588 Set time (s) after boot for CPU-hotplug testing.
3591 Set time (s) between CPU-hotplug operations, or
3592 zero to disable CPU-hotplug testing.
3595 Do periodic testing of real-time lock priority
3600 non-real-time spinlocks, due to their disabling
3601 of preemption. Note that non-realtime mutexes
3614 Set task-shuffle interval (jiffies). Shuffling
3615 tasks allows some CPUs to go into dyntick-idle
3620 is useful for hands-off automated testing.
3639 Run the write-side locktorture kthreads at
3640 sched_set_fifo() real-time priority.
3658 7 (KERN_DEBUG) debug-level messages
3670 logo.nologo [FB] Disables display of the built-in Linux logo.
3688 an IEEE 1284-compliant printer is attached; if
3694 time-consuming boot-time autodetection (up to 250 ms per
3714 Example: machtype=lemote-yeeloong-2f-7inch
3726 (loop.max_loop) unconditionally pre-created at init time. The default
3729 devices can be requested on-demand with the
3730 /dev/loop-control interface.
3732 mce= [X86-{32,64}]
3769 do not opt-in to Local MCE delivery. Use legacy method
3790 don't overwrite the bios-set CMCI threshold. This boot
3799 force-enable recoverable machine check code paths
3805 See Documentation/admin-guide/md.rst.
3808 Control mitigation for the Micro-architectural Data
3823 full - Enable MDS mitigation on vulnerable CPUs
3824 full,nosmt - Enable MDS mitigation and disable
3826 off - Unconditionally disable MDS mitigation
3828 On TAA-affected machines, mds=off can be prevented by
3837 For details see: Documentation/admin-guide/hw-vuln/mds.rst
3842 mem=nn[KMG] [KNL,BOOT,EARLY] Force usage of a specific amount
3852 [ARC,MICROBLAZE] - the limit applies only to low memory,
3855 [ARM64] - only limits memory covered by the linear
3868 [ARM,MIPS,EARLY] - override the memory layout
3875 mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
3882 per-device physically contiguous DMA buffers.
3890 See Documentation/admin-guide/mm/memory-hotplug.rst.
3899 [KNL, X86,MIPS,XTENSA,EARLY] Force usage of a specific region of memory.
3909 [KNL,ACPI,EARLY] Mark specific memory as ACPI data.
3913 [KNL,ACPI,EARLY] Mark specific memory as reserved.
3915 Example: Exclude memory from 0x18690000-0x1869ffff
3924 [KNL,X86] Mark specific memory as protected.
3929 memmap=<size>%<offset>-<oldtype>+<newtype>
3931 from <oldtype> to <newtype>. If "-<oldtype>" is left
3946 repeatable BIOS-originated corruption always
3990 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control
3996 Refer to Documentation/virt/kvm/x86/amd-memory-encryption.rst
4000 s2idle - Suspend-To-Idle
4001 shallow - Power-On Suspend or equivalent (if supported)
4002 deep - Suspend-To-RAM or equivalent (if supported)
4003 See Documentation/admin-guide/pm/sleep-states.rst.
4005 mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
4015 base_rev=X - with <X> with format: <u32>
4029 0 - The attached screen is the 3.5" TFT
4030 1 - The attached screen is the 7" TFT
4031 2 - The VGA Shield is attached (1024x768)
4035 b - Enable backlight. The TFT backlight pin will be
4039 c - Enable the s3c camera interface.
4040 t - Reserved for enabling touchscreen support. The
4044 https://repo.or.cz/w/linux-2.6/mini2440.git
4049 arch-independent options, each of which is an
4050 aggregation of existing arch-specific options.
4080 ssbd=force-off [ARM64]
4095 have other ways of avoiding SMT-based attacks.
4109 supports attack-vector based controls as documented in
4110 Documentation/admin-guide/hw-vuln/attack_vector_controls.rst
4134 full - Enable mitigation on vulnerable CPUs
4136 full,nosmt - Enable mitigation and disable SMT on
4139 off - Unconditionally disable mitigation
4152 Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst
4164 specific module, use the module specific control that
4168 the specific module.
4182 module_blacklist= [KNL] Do not load a comma-separated list of
4207 movable_node [KNL,EARLY] Boot-time switch to make hotplugable memory
4214 Format: <name>,<region-number>,<size>,<offset>
4217 <name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
4292 [NFS] enable 64-bit inode numbers.
4293 If zero, the NFS client will fake up a 32-bit inode
4295 of returning the full 64-bit number.
4296 The default is to return 64-bit inode numbers.
4331 [NFS4] Specify an additional fixed unique ident-
4362 driver. A non-zero value sets the minimum interval
4367 server-to-server copies for which this server is
4379 server-to-server copy, knfsd temporarily mounts
4386 See Documentation/admin-guide/nfs/nfsroot.rst.
4388 nfsroot= [NFS] nfs root filesystem for disk-less boxes.
4389 See Documentation/admin-guide/nfs/nfsroot.rst.
4392 See Documentation/admin-guide/nfs/nfsroot.rst.
4396 NMI stack-backtrace request.
4405 0 - turn hardlockup detector in nmi_watchdog off
4406 1 - turn hardlockup detector in nmi_watchdog on
4407 rNNN - configure the watchdog with raw perf event 0xNNN
4420 no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes.
4421 Forces kernel to use 3-level paging instead.
4423 no5lvl [X86-64,RISCV,EARLY] Disable 5-level paging mode. Forces
4424 kernel to use 4-level paging instead.
4459 no_entry_flush [PPC,EARLY] Don't flush the L1-D cache when entering the kernel.
4461 noexec32 [X86-64]
4462 This affects only 32-bit executables.
4463 noexec32=on: enable non-executable mappings (default)
4465 noexec32=off: disable non-executable mappings
4476 nofxsr [BUGS=X86-32] Disables x86 floating point extended
4478 legacy floating-point registers on task switch.
4525 nointremap [X86-64,Intel-IOMMU,EARLY] Do not enable interrupt
4527 [Deprecated - use intremap=off]
4533 noirqdebug [X86-32] Disables the code which attempts to detect and
4543 no-kvmapf [X86,KVM,EARLY] Disable paravirtualized asynchronous page
4546 no-kvmclock [X86,KVM,EARLY] Disable paravirtualized KVM clock driver
4548 nolapic [X86-32,APIC,EARLY] Do not enable or use the local APIC.
4550 nolapic_timer [X86-32,APIC,EARLY] Do not use the local APIC timer.
4552 nomce [X86-32] Disable Machine Check Exception
4554 nomfgpt [X86-32] Disable Multi-Function General Purpose
4560 not load if they could possibly displace the pre-
4563 perform display-mode changes or accelerated rendering.
4576 nopcid [X86-64,EARLY] Disable the PCID cpu feature.
4581 nopti [X86-64,EARLY]
4597 noreplace-smp [X86-32,SMP] Don't replace SMP instructions
4603 no-scroll [VGA] Disables scrollback.
4604 This is required for the Braillex ib80-piezo Braille
4607 nosgx [X86-64,SGX,EARLY] Disables Intel SGX kernel support.
4627 nosoftlockup [KNL] Disable the soft-lockup detector.
4633 nospectre_bhb [ARM64,EARLY] Disable all mitigations for Spectre-BHB (branch
4646 no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV,LOONGARCH,EARLY]
4653 timer IRQ sources, i.e., the IO-APIC timer. This can
4658 [PPC,EARLY] Don't flush the L1-D cache after accessing user data.
4671 no-vmw-sched-clock
4676 soft-lockup and NMI watchdog (hard-lockup).
4680 nox2apic [X86-64,APIC,EARLY] Do not enable x2APIC mode.
4688 enabling legacy floating-point and sse state.
4710 n. So during boot up some boot time memory for per-cpu
4711 variables need be pre-allocated for later physical cpu
4738 soft-reserved memory partitioning.
4747 See Documentation/admin-guide/sysctl/vm.rst for details.
4749 nvme.quirks= [NVME] A list of quirk entries to augment the built-in
4751 '-' character.
4753 The IDs are 4-digits hex numbers and quirk_names is a
4759 nvme.quirks=7710:2267:bogus_nid,^identify_cns-9900:7711:broken_msi
4762 See Documentation/core-api/debugging-via-ohci1394.rst for more
4777 onenand.bdry= [HW,MTD] Flex-OneNAND Boundary Configuration
4781 boundary - index of last SLC block on Flex-OneNAND.
4783 lock - Configure if Flex-OneNAND boundary should be locked.
4802 page_owner= [KNL,EARLY] Boot-time page_owner enabling option.
4808 page_poison= [KNL,EARLY] Boot-time parameter changing the state of
4836 See Documentation/admin-guide/tainted-kernels.rst for
4844 [KNL,SMP] Force panic handling to execute on a specific CPU.
4847 specific CPU for the crash kernel to function correctly.
4849 constraints, or platform-specific requirements where only
4915 a specific mode. This is necessary on Pegasos
4923 Set to non-zero to probe primary and secondary ISA
4929 Set to non-zero if a chip is present that snoops speed
4977 Set to non-zero to probe tertiary and further ISA
4993 Set to non-zero to probe QDI controllers. By default
4998 Set to non-zero to probe Winbond controllers. Use
5018 Some options herein operate on a specific device
5043 bios [X86-32] force use of PCI BIOS, don't access
5045 has a non-standard PCI host bridge.
5046 nobios [X86-32] disallow use of PCI BIOS, only direct
5052 data in IO port 0xCFC, both 32-bit).
5054 Mechanism 2 (IO port 0xCF8 is an 8-bit port for
5055 the function, IO port 0xCFA, also 8-bit, sets
5057 through ports 0xC000-0xCFFF).
5064 root domains (aka PCI segments, in ACPI-speak).
5072 disable the use of MSI interrupts system-wide.
5077 primary IO-APIC for bridges that cannot disable
5084 biosirq [X86-32] Use PCI BIOS calls to get the interrupt
5108 F0000h-100000h range.
5113 assign-busses [X86] Always assign all PCI bus
5134 <linux-pci@vger.kernel.org>.
5138 a bug to <linux-pci@vger.kernel.org>.
5150 bfsort Sort PCI devices into breadth-first order.
5153 nobfsort Don't sort PCI devices into breadth-first order.
5155 tuning and use the BIOS-configured MPS defaults.
5165 configuration allows peer-to-peer DMA between
5168 that hot-added devices will work.
5183 A PCI-PCI bridge can be specified if resource
5189 for 4096-byte alignment.
5191 end-to-end CRC checking). Only effective if
5222 noats [PCIE, Intel-IOMMU, AMD-IOMMU]
5253 bit-0 : ACS Source Validation
5254 bit-1 : ACS Translation Blocking
5255 bit-2 : ACS P2P Request Redirect
5256 bit-3 : ACS P2P Completion Redirect
5257 bit-4 : ACS Upstream Forwarding
5258 bit-5 : ACS P2P Egress Control
5259 bit-6 : ACS Direct Translated P2P
5269 Validation unchanged from whatever power-up
5281 system-wide.
5295 dpc-native Use native PCIe service for DPC only. May
5312 Keep all power-domains already enabled by bootloader on,
5330 pirq= [SMP,APIC] Manual mp-table setup
5331 See Documentation/arch/x86/i386/IO-APIC.rst.
5335 See also Documentation/admin-guide/parport.rst.
5354 resume of devices during system-wide power transitions.
5356 dependencies are not well-defined, or for debugging
5366 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
5375 { on | off | curr | res | no-curr | no-res }
5404 platform machine description specific power_save
5420 none - Limited to cond_resched() calls
5421 voluntary - Limited to cond_resched() and might_sleep() calls
5422 full - Any section that isn't explicitly preempt disabled
5426 lazy - Scheduler controlled. Similar to full but instead
5432 print-fatal-signals=
5438 coredump - etc.
5441 you might want to try "ulimit -i unlimited".
5453 or lockdep-detected issues (only if lock debug is on).
5461 Allows storing messages from non-panic CPUs into
5463 flushed to consoles by the panic-CPU on
5464 a best-effort basis.
5470 on - unlimited logging to /dev/kmsg from userspace
5471 off - logging to /dev/kmsg disabled
5472 ratelimit - ratelimit the logging
5483 - 'always': traditional behavior always allows mem overrides.
5484 - 'ptrace': only allow mem overrides for active ptracers.
5485 - 'never': never allow mem overrides.
5489 Limit processor to maximum C-state
5493 Ignore the _CST method to determine C-states,
5500 Param: "schedule" - profile schedule points.
5501 Param: "kvm" - profile VM exits.
5502 Param: <number> - step/bucket size as a power of 2 for
5531 pti= [X86-64] Control Page Table Isolation of user and
5536 on - unconditionally enable
5537 off - unconditionally disable
5538 auto - kernel detects whether your CPU model is
5544 [KNL] Number of legacy pty's. Overwrites compiled-in
5556 See Documentation/admin-guide/md.rst.
5559 See Documentation/admin-guide/blockdev/ramdisk.rst.
5578 cross-syscall address exposures. This is only
5584 ras=option[,option,...] [KNL] RAS-specific options
5590 rcu_nocbs[=cpu-list]
5595 enable the no-callback CPU mode, which prevents
5600 "p" for RCU-preempt, "s" for RCU-sched, and "g"
5604 and real-time workloads. It can also improve
5608 list of CPUs is set to no-callback mode from boot.
5612 no-callback mode from boot but the mode may be
5623 This improves the real-time response for the
5634 Do only a one-line RCU CPU stall warning when
5635 there is an ongoing too-long CSD-lock wait.
5641 If triggered before the RCU grace-period machinery
5651 RCU grace-period cleanup.
5655 RCU grace-period initialization.
5659 RCU grace-period pre-initialization, that is,
5660 the propagation of recent CPU-hotplug changes up
5664 Set delay from grace-period initialization to
5677 soliciting quiescent-state help from
5689 Set the SCHED_FIFO priority of the RCU per-CPU
5692 and for the RCU grace-period kthreads (rcu_bh,
5694 set, valid values are 1-99 and the default is 1
5695 (the least-favored priority). Otherwise, when
5696 RCU_BOOST is not set, valid values are 0-99 and
5697 the default is zero (non-realtime operation).
5702 On callback-offloaded (rcu_nocbs) CPUs,
5705 use of the ->nocb_bypass list. However, in the
5706 common non-flooded case, RCU queues directly to
5707 the main ->cblist in order to avoid the extra
5708 overhead of the ->nocb_bypass list and its lock.
5710 a single jiffy, RCU pre-queues the callbacks into
5711 the ->nocb_bypass queue. The definition of "too
5715 On callback-offloaded (rcu_nocbs) CPUs, avoid
5728 batch limiting is re-enabled.
5732 RCU's force-quiescent-state scan will aggressively
5740 Set the page-cache refill delay (in milliseconds)
5741 in response to low-memory conditions. The range
5745 Set the shift-right count to use to compute
5746 the callback-invocation batch limit bl from
5753 Please note that this callback-invocation batch
5754 limit applies only to non-offloaded callback
5763 cache-to-cache transfer latencies.
5769 and for NUMA systems with large remote-access
5785 the wakeup overhead on the global grace-period
5787 each group's NOCB grace-period kthread.
5790 Cause the grace-period kthread to get an extra
5792 it should at force-quiescent-state time.
5805 this specifies an rcu_read_unlock()-time delay
5809 of RCU-protected pointers after the relevant
5819 per-CPU rcuc kthreads. Defaults to a non-zero
5849 grace-period primitives such as call_rcu().
5860 grace-period primitives.
5863 Set test-start holdoff period. The purpose of
5881 Test the double-argument variant of kfree_rcu().
5883 rcuscale.kfree_rcu_test_single, both the single-
5884 and double-argument variants are tested.
5887 Test the single-argument variant of kfree_rcu().
5889 rcuscale.kfree_rcu_test_double, both the single-
5890 and double-argument variants are tested.
5904 does not affect the data-collection interval,
5909 Set number of RCU readers. The value -1 selects
5911 "n" less than -1 selects N-n+1, where N is again
5912 the number of CPUs. For example, -2 selects N
5913 (the number of CPUs), -3 selects N+1, and so on.
5914 A value of "n" less than or equal to -N selects
5927 complete. This is useful for hands-off automated
5934 Write-side holdoff between grace periods,
5939 Additional write-side holdoff between grace
5957 for RCU grace-period forward-progress testing
5964 Specify the fraction of a CPU-stall-warning
5965 period to do tight-loop forward-progress testing.
5969 forward-progress tests.
5973 need_resched() during tight-loop forward-progress
5977 Use conditional/asynchronous update-side
5978 normal-grace-period primitives, if available.
5981 Use conditional/asynchronous update-side
5982 expedited-grace-period primitives, if available.
5985 Use conditional/asynchronous update-side
5986 normal-grace-period primitives that also take
5991 Use conditional/asynchronous update-side
5992 expedited-grace-period primitives that also take
6016 Use expedited update-side primitives, if available.
6019 Use normal (non-expedited) asynchronous
6020 update-side primitives, if available.
6023 Use polled update-side normal-grace-period
6027 Use polled update-side expedited-grace-period
6031 Use polled update-side normal-grace-period
6036 Use polled update-side expedited-grace-period
6060 Use normal (non-expedited) synchronous
6061 update-side primitives, if available. If all
6065 they are all non-zero.
6068 Enable grace-period wrap lag testing. Setting
6073 Set the value for grace-period wrap lag during
6088 the grace-period wrap lag will be set to the
6098 Leak an RCU-protected pointer out of the reader.
6113 Set number of RCU callback-offload togglers.
6118 callback-offload toggling attempts.
6121 Set number of RCU readers. The value -1 selects
6122 N-1, where N is the number of CPUs. A value
6123 "n" less than -1 selects N-n-2, where N is again
6124 the number of CPUs. For example, -2 selects N
6125 (the number of CPUs), -3 selects N+1, and so on.
6128 Enable debug-object double-call_rcu() testing.
6131 Set time (s) after boot for CPU-hotplug testing.
6134 Set time (jiffies) between CPU-hotplug operations,
6135 or zero to disable CPU-hotplug testing.
6139 by a high-priority FIFO real-time task. Set to
6148 second) between preemptions by a high-priority
6149 FIFO real-time task. This delay is mediated
6154 The number of times in a given read-then-exit
6155 episode that a set of read-then-exit kthreads
6160 read-then-exit testing episodes.
6165 are entered from low-order bit up, and are
6167 0x1 bit is normal readers, 0x2 NMI-safe readers,
6168 and 0x4 light-weight readers.
6171 Set task-shuffle interval (s). Shuffling tasks
6172 allows some CPUs to go into dyntick-idle mode
6177 is useful for hands-off automated testing.
6186 any other stall-related activity. Note that
6192 in scheduling-while-atomic splats.
6211 grace-period kthread to test RCU CPU stall
6235 of RCU priority-boost testing. Defaults to zero,
6242 Test RCU's dyntick-idle handling. See also the
6297 Use expedited grace-period primitives, for
6301 real-time latency, and degrade energy efficiency.
6305 Use only normal grace-period primitives,
6308 real-time latency, CPU utilization, and
6310 increased grace-period latency. This parameter
6317 only normal grace-period primitives. No effect
6323 post-boot attempt at an expedited RCU grace
6324 period to instead use normal non-expedited
6325 grace-period processing.
6333 set to the default value of -1.
6336 Set the minimum number of callback-queuing-time
6337 lock-contention events per jiffy required to
6338 cause the RCU Tasks flavors to switch to per-CPU
6341 the default value of -1.
6346 of -1 allows this to be automatically (and
6352 cancel laziness on that CPU. Use -1 to disable
6362 only printed prior to the stall-warning message
6402 force - Override the decision by the kernel to hide the
6446 There are some built-in platform specific "quirks"
6447 - you may see: "reboot: <name> series board detected.
6451 built-in quirk table, and use the generic default
6484 Set test-start holdoff period. The purpose of
6499 but the default has already reduced the per-pass
6504 Set number of readers. The default value of -1
6513 Set the read-side critical-section duration,
6517 Specify the read-protection implementation to test.
6543 See Documentation/admin-guide/cgroup-v1/cpusets.rst.
6573 reservetop= [X86-32,EARLY]
6590 See Documentation/power/swsusp-and-swap-files.rst
6606 AMD-based UNRET and IBPB mitigations alone do not stop
6608 sibling threads. For that reason, STIBP is used on pro-
6612 off - no mitigation
6613 auto - automatically select a mitigation
6614 auto,nosmt - automatically select a mitigation,
6618 ibpb - On AMD, mitigate short speculation
6623 ibpb,nosmt - Like "ibpb" above but will disable SMT
6627 unret - Force enable untrained return thunks,
6628 only effective on AMD f15h-f17h based
6630 unret,nosmt - Like unret, but will disable SMT when STIBP
6670 ro [KNL] Mount root device read-only on boot
6673 on Mark read-only kernel memory as read-only (default).
6674 off Leave read-only kernel memory writable for debugging.
6675 noalias Mark read-only kernel memory as read-only but retain
6683 debug-uart get routed to the D+ and D- pins of the usb
6689 block/early-lookup.c for details.
6731 rw [KNL] Mount root device read-write on boot
6758 solution to mutex-based priority inversion.
6788 to 10 seconds for built-in smp_call_function()
6795 that requesting even small non-zero numbers of
6802 The default of -1 specifies a number of kthreads
6807 test before initiating CPU-hotplug operations.
6811 CPU-hotplug operations. Specifying zero (which
6812 is the default) disables CPU-hotplug operations.
6818 Non-zero values are useful for automated tests.
6841 "wait" parameter. A value of -1 selects the
6842 default if all other weights are -1. However,
6844 value of -1 will instead select a weight of zero.
6849 non-zero "wait" parameter. See weight_single.
6862 non-zero "wait" parameter. See weight_single
6874 non-zero "wait" parameter. See weight_single
6885 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1"
6886 1 -- enable.
6897 0 -- disable.
6898 1 -- enable.
6901 serialnumber [BUGS=X86-32]
6903 sev=option[,option...] [X86-64]
6909 Do not enable SEV-SNP (applies to host/hypervisor
6912 SEV-SNP guests.
6920 to set it to "all" by meaning -- no limit here.
6932 Documentation/admin-guide/mm/slab.rst.
6943 Documentation/admin-guide/mm/slab.rst.
6959 Documentation/admin-guide/mm/slab.rst.
6965 Documentation/admin-guide/mm/slab.rst.
6980 Documentation/admin-guide/mm/slab.rst.
7007 using the csdlock_debug- kernel parameter.
7012 system. By default, let CSD-lock acquisition
7014 for this value provides a 5-minute timeout.
7016 smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
7017 smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
7018 smsc-ircc2.ircc_sir= [HW] SIR base I/O port
7019 smsc-ircc2.ircc_fir= [HW] FIR base I/O port
7020 smsc-ircc2.ircc_irq= [HW] IRQ line
7021 smsc-ircc2.ircc_dma= [HW] DMA channel
7022 smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
7032 Default: -1 (no limit)
7035 [KNL] Should the soft-lockup detector generate panics.
7038 A value of non-zero instructs the soft-lockup detector
7039 to panic the machine when a soft-lockup duration exceeds
7042 respective build-time switch to that functionality.
7045 [KNL] Should the soft-lockup detector generate
7050 See Documentation/admin-guide/laptops/sonypi.rst
7057 on - (default) Enable the HW or SW mitigation as
7060 vmexit - On systems which don't have the HW mitigation
7063 protected from VM-originated BHI attacks, but
7065 off - Disable the mitigation.
7072 on - unconditionally enable, implies
7074 off - unconditionally disable, implies
7076 auto - kernel detects whether your CPU model is
7087 Selecting specific mitigation does not force enable
7093 Specific mitigations can also be selected manually:
7095 retpoline - replace indirect branches
7096 retpoline,generic - Retpolines
7097 retpoline,lfence - LFENCE; indirect branch
7098 retpoline,amd - alias for retpoline,lfence
7099 eibrs - Enhanced/Auto IBRS
7100 eibrs,retpoline - Enhanced/Auto IBRS + Retpolines
7101 eibrs,lfence - Enhanced/Auto IBRS + LFENCE
7102 ibrs - use IBRS to protect kernel
7112 on - Unconditionally enable mitigations. Is
7115 off - Unconditionally disable mitigations. Is
7118 prctl - Indirect branch speculation is enabled,
7124 - Like "prctl" above, but only STIBP is
7130 - Same as "prctl" above, but all seccomp
7135 - Like "seccomp" above, but only STIBP is
7140 auto - Kernel selects the mitigation depending on
7151 off - Disable mitigation
7152 microcode - Enable microcode mitigation only
7153 safe-ret - Enable sw-only safe RET mitigation (default)
7154 ibpb - Enable mitigation by issuing IBPB on
7156 ibpb-vmexit - Issue IBPB only on VMEXIT
7157 (cloud-specific mitigation)
7182 on - Unconditionally disable Speculative Store Bypass
7183 off - Unconditionally enable Speculative Store Bypass
7184 auto - Kernel detects whether the CPU model contains an
7190 prctl - Control Speculative Store Bypass per thread
7194 seccomp - Same as "prctl" above, but all seccomp threads
7202 on,auto - On Power8 and Power9 insert a store-forwarding
7206 off - No action.
7212 [X86,EARLY] Split the LLC N-ways
7232 off - not enabled
7234 warn - the kernel will emit rate-limited warnings
7242 fatal - the kernel will send SIGBUS to applications
7247 ratelimit:N -
7267 Certain CPUs are vulnerable to an MDS-like
7287 This kernel-boot parameter defaults to 128,
7288 but takes effect only when the low-order four
7305 instead of the compile-time CONFIG_NR_CPUS.
7309 grace-period sequence counter wrap for the
7310 srcu_data structure's ->srcu_gp_seq_needed field.
7325 Specifies the number of no-delay instances
7332 Specifies the per-grace-period phase, number of
7333 non-sleeping polls of readers. Beyond this limit,
7339 Specifies number of microseconds of non-sleeping
7340 delay between each non-sleeping poll of readers.
7343 Specifies the number of update-side contention
7348 set for contention-based conversions to occur.
7358 force-on: Unconditionally enable mitigation for
7360 force-off: Unconditionally disable mitigation for
7382 stack traces. Pools are allocated on-demand up to this
7388 stacktrace_filter=[function-list]
7390 will trace at boot up. function-list is a comma-separated
7398 Set the STI (builtin display/keyboard on the HP-PARISC
7400 as the initial boot-console.
7463 to global on non-NUMA machines)
7488 <int> -- Number of I/O TLB slabs
7489 <int> -- Second integer after comma. Number of swiotlb
7492 force -- force using of bounce buffers even if they
7494 noforce -- Never use bounce buffers (for debugging)
7509 Ignore sysrq setting - this boot parameter will
7517 cache size. See Documentation/networking/ip-sysctl.rst
7524 Specify "mem" (for Suspend-to-RAM) or "standby" (for
7529 wakeup-capable RTC alarm.
7535 -1: disable all active trip points in all thermal zones
7539 -1: disable all critical trip points in all thermal zones
7546 -1: disable all passive trip points
7552 <deci-seconds>: poll all this frequency
7556 Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
7561 See Documentation/admin-guide/mm/transhuge.rst for more
7569 Format: <size>[KMG],<size>[KMG]:<policy>;<size>[KMG]-<size>[KMG]:<policy>
7575 See Documentation/admin-guide/mm/transhuge.rst for more
7587 Prevent the CPU-hotplug component of torturing
7591 Dump the ftrace buffer at torture-test shutdown,
7595 with rotating-rust storage.
7600 disables verbose-printk() sleeping.
7603 Duration of each verbose-printk() sleep in jiffies.
7636 https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
7674 local - Use the per CPU time stamp counter
7678 global - Event time stamps are synchronized across
7681 counter - Simple counting of events (1, 2, ..)
7685 uptime - Use jiffies as the time stamp.
7686 perf - Use the same clock that perf uses.
7687 mono - Use ktime_get_mono_fast_ns() for time stamps.
7688 mono_raw - Use ktime_get_raw_fast_ns() for time
7690 boot - Use ktime_get_boot_fast_ns() for time stamps.
7694 trace_event=[event-list]
7696 to facilitate early boot debugging. The event-list is a
7697 comma-separated list of trace events to enable. See
7704 The value before :mod: will only enable specific events
7708 trace_instance=[instance-info]
7733 traceoff - Have the tracing instance tracing disabled after it is created.
7734 traceprintk - Have trace_printk() write into this trace instance
7781 trace_options=[option-list]
7783 The option-list is a comma delimited list of options
7797 trace_trigger=[trigger-list]
7798 [FTRACE] Add an event trigger on specific events.
7799 Set a trigger on top of a specific event, with an optional
7843 See Documentation/admin-guide/mm/transhuge.rst
7850 See Documentation/admin-guide/mm/transhuge.rst
7857 See Documentation/admin-guide/mm/transhuge.rst
7865 - "tpm"
7866 - "tee"
7867 - "caam"
7868 - "dcp"
7869 - "pkwm"
7895 - "kernel"
7896 - the same value as trusted.source: "tpm" or "tee"
7897 - "default"
7920 off - disable the mitigation
7921 on - enable the mitigation (default)
7922 user - mitigate only user/kernel transitions
7923 vm - mitigate only guest/host transitions
7931 high-resolution timer mode on older hardware, and in
7962 on - Enable TSX on the system. Although there are
7965 several previous speculation-related CVEs, and
7969 off - Disable TSX on the system. (Note that this
7977 auto - Disable TSX if X86_BUG_TAA is present,
7982 See Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
7988 Similar to Micro-architectural Data Sampling (MDS)
8003 full - Enable TAA mitigation on vulnerable CPUs
8006 full,nosmt - Enable TAA mitigation and disable SMT on
8009 vulnerable to cross-thread TAA attacks.
8010 off - Unconditionally disable TAA mitigation
8012 On MDS-affected machines, tsx_async_abort=off can be
8024 Documentation/admin-guide/hw-vuln/tsx_async_abort.rst
8030 See also Documentation/input/devices/joystick-parport.rst
8032 udbg-immortal [PPC] When debugging early kernel crashes that
8038 Set number of hash buckets for UDP/UDP-Lite connections
8040 uhci-hcd.ignore_oc=
8042 Some badly-designed motherboards generate lots of
8067 unwind_debug [X86-64,EARLY]
8075 (default -1 = authorized (same as 1),
8081 for newly-detected USB devices (default 2). This
8109 [USB] Specifies timeout for the initial 64-byte
8116 [USB] A list of quirk entries to augment the built-in
8119 VendorID:ProductID:Flags. The IDs are 4-digit hex
8121 will change the built-in quirk; setting it if it is
8126 a 255-byte read);
8130 Set-Interface requests);
8149 (bInterval-1).
8190 usb-storage.delay_use=
8197 usb-storage.quirks=
8199 override the built-in unusual_devs list. List
8202 and Product ID values (4-digit hex numbers) and
8204 to a common usb-storage quirk flag as follows:
8246 medium is write-protected).
8255 1 - undefined instruction events
8256 2 - system calls
8257 4 - invalid data aborts
8258 8 - SIGSEGV faults
8259 16 - SIGBUS faults
8268 vdso32= [X86] Control the 32-bit vDSO
8269 vdso32=1: enable 32-bit VDSO
8270 vdso32=0 or vdso32=2: disable 32-bit VDSO
8280 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
8311 vga= [BOOT,X86-32] Select a particular video mode
8313 Documentation/admin-guide/svga.rst.
8323 enabling or disabling specific virtual memory
8328 - Disable all of the above options
8354 hypervisor to a guest via speculative side-channels.
8356 off - disable the mitigation
8357 ibpb - use Indirect Branch Prediction Barrier
8359 force - force vulnerability detection even on
8362 vsyscall= [X86-64,EARLY]
8365 code). Most statically-linked binaries and older
8391 see vga-softcursor.rst. Default: 2 = underline.
8396 This is a 16-member array composed of values
8397 ranging from 0-255.
8402 This is a 16-member array composed of values
8403 ranging from 0-255.
8408 This is a 16-member array composed of values
8409 ranging from 0-255.
8414 Set system-wide default UTF-8 mode for all tty's.
8415 Default is 1, i.e. UTF-8 mode is enabled for all
8420 Format=<-1|0|1>
8421 Set system-wide default for whether a cursor
8422 is shown on new VTs. Default is -1,
8427 vt.italic= [VT] Default color for italic text; 0-15.
8430 vt.underline= [VT] Default color for underlined text; 0-15.
8434 see Documentation/watchdog/watchdog-parameters.rst
8435 or other driver-specific files in the
8449 Format: <cpu-list>
8476 The default is 0, which disables the time-based panic.
8479 Per-cpu work items which run for longer than this
8482 them from noticeably delaying other per-cpu work
8500 Per-cpu workqueues are generally preferred because
8502 locality; unfortunately, per-cpu workqueues tend to
8505 Enabling this makes the per-cpu workqueues which
8520 Documentation/core-api/workqueue.rst.
8533 forces round-robin CPU selection to flush out
8535 When enabled, memory and cache locality will be
8541 on - Enable writecombine, use WUC for ioremap_wc()
8542 off - Disable writecombine, use SUC for ioremap_wc()
8544 x2apic_phys [X86-64,APIC,EARLY] Use x2apic physical mode instead of
8548 xen_512gb_limit [KNL,X86-64,XEN]
8563 ide-disks -- unplug primary master IDE devices
8564 aux-ide-disks -- unplug non-primary-master IDE devices
8565 nics -- unplug network devices
8566 all -- unplug all emulated devices (NICs and IDE disks)
8567 unnecessary -- unplugging emulated devices is
8570 never -- do not unplug even if version check succeeds
8584 Select whether to always use non-faulting (safe) MSR
8604 xen_timer_slop= [X86-64,XEN,EARLY]
8629 preferred over the 2-level event handling, as it is
8646 xive.store-eoi=off [PPC]
8652 xhci-hcd.quirks [USB,KNL]