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Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 422 |
1 files changed, 229 insertions, 193 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 4d0f545fb3ec..e75344f4e0cd 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -8,6 +8,8 @@ ARM64 ARM64 architecture is enabled. CLK Common clock infrastructure is enabled. CMA Contiguous Memory Area support is enabled. + CPU_FREQ CPU frequency scaling is enabled. + CPU_IDLE CPU idle time management is enabled. DRM Direct Rendering Management support is enabled. DYNAMIC_DEBUG Build in debug messages and enable them at runtime EARLY Parameter processed too early to be embedded in initrd. @@ -24,7 +26,6 @@ IP_PNP IP DHCP, BOOTP, or RARP is enabled. IPV6 IPv6 support is enabled. ISAPNP ISA PnP code is enabled. - ISDN Appropriate ISDN support is enabled. ISOL CPU Isolation is enabled. JOY Appropriate joystick support is enabled. KGDB Kernel debugger support is enabled. @@ -36,7 +37,6 @@ M68k M68k architecture is enabled. These options have more detailed description inside of Documentation/arch/m68k/kernel-options.rst. - MDA MDA console support is enabled. MIPS MIPS architecture is enabled. MOUSE Appropriate mouse support is enabled. MSI Message Signaled Interrupts (PCI). @@ -49,6 +49,7 @@ PCI PCI bus support is enabled. PCIE PCI Express support is enabled. PCMCIA The PCMCIA subsystem is enabled. + PM Power Management support is enabled. PNP Plug & Play support is enabled. PPC PowerPC architecture is enabled. PPT Parallel port support is enabled. @@ -558,9 +559,6 @@ Kernel parameters 1 -- enable. Default value is set via kernel config option. - arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards - Format: <io>,<irq>,<nodeID> - arm64.no32bit_el0 [ARM64] Unconditionally disable the execution of 32 bit applications. @@ -570,6 +568,9 @@ Kernel parameters arm64.nogcs [ARM64] Unconditionally disable Guarded Control Stack support + arm64.nohaft [ARM64] Unconditionally disable Hardware managed Access + Flag for Table descriptors support + arm64.nomops [ARM64] Unconditionally disable Memory Copy and Memory Set instructions support @@ -588,6 +589,9 @@ Kernel parameters arm64.nosve [ARM64] Unconditionally disable Scalable Vector Extension support + arm64.nowfxt [ARM64] Unconditionally disable Wait For Event with + Timeout and Wait For Interrupt with Timeout support + ataflop= [HW,M68k] atarimouse= [HW,MOUSE] Atari Mouse @@ -789,24 +793,6 @@ Kernel parameters cio_ignore= [S390] See Documentation/arch/s390/common_io.rst for details. - clearcpuid=X[,X...] [X86] - Disable CPUID feature X for the kernel. See - arch/x86/include/asm/cpufeatures.h for the valid bit - numbers X. Note the Linux-specific bits are not necessarily - stable over kernel options, but the vendor-specific - ones should be. - X can also be a string as appearing in the flags: line - in /proc/cpuinfo which does not have the above - instability issue. However, not all features have names - in /proc/cpuinfo. - Note that using this option will taint your kernel. - Also note that user programs calling CPUID directly - or using the feature without checking anything - will still see it. This just prevents it from - being used by the kernel or shown in /proc/cpuinfo. - Also note the kernel might malfunction if you disable - some critical bits. - clk_ignore_unused [CLK] Prevents the clock framework from automatically gating @@ -895,6 +881,10 @@ Kernel parameters contiguous memory allocations. It will reserve CMA area for the specified node. + If it is setup together with upper 'cmd_pernuma=' + (unlikely), its size setting takes priority for the + specified numa nodes. + With numa CMA enabled, DMA users on node nid will first try to allocate buffer from the numa area which is located in node nid, if the allocation fails, @@ -911,17 +901,6 @@ Kernel parameters Sets the size of memory pool for coherent, atomic dma allocations, by default set to 256K. - com20020= [HW,NET] ARCnet - COM20020 chipset - Format: - <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] - - com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers) - Format: <io>[,<irq>] - - com90xx= [HW,NET] - ARCnet - COM90xx chipset (memory-mapped buffers) - Format: <io>[,<irq>[,<memstart>]] - condev= [HW,S390] console device conmode= @@ -1119,14 +1098,14 @@ Kernel parameters It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. crashkernel=size[KMG],cma - [KNL, X86, ppc] Reserve additional crash kernel memory from - CMA. This reservation is usable by the first system's - userspace memory and kernel movable allocations (memory - balloon, zswap). Pages allocated from this memory range - will not be included in the vmcore so this should not - be used if dumping of userspace memory is intended and - it has to be expected that some movable kernel pages - may be missing from the dump. + [KNL, X86, ARM64, RISCV, PPC] Reserve additional crash + kernel memory from CMA. This reservation is usable by + the first system's userspace memory and kernel movable + allocations (memory balloon, zswap). Pages allocated + from this memory range will not be included in the vmcore + so this should not be used if dumping of userspace memory + is intended and it has to be expected that some movable + kernel pages may be missing from the dump. A standard crashkernel reservation, as described above, is still needed to hold the crash kernel and initrd. @@ -1246,8 +1225,9 @@ Kernel parameters deferred probe to give up waiting on dependencies to probe. Only specific dependencies (subsystems or drivers) that have opted in will be ignored. A timeout - of 0 will timeout at the end of initcalls. If the time - out hasn't expired, it'll be restarted by each + of 0 will timeout at the end of initcalls; a negative + value is treated as an infinite timeout value. If the + timeout hasn't expired, it'll be restarted by each successful driver registration. This option will also dump out devices still on the deferred probe list after retrying. @@ -1643,10 +1623,17 @@ Kernel parameters on all PCI bridges while in the EFI boot stub efi_no_storage_paranoia [EFI,X86,EARLY] - Using this parameter you can use more than 50% of - your efi variable storage. Use this parameter only if - you are really sure that your UEFI does sane gc and - fulfills the spec otherwise your board may brick. + The kernel reserves 5KB of EFI variable storage for + safety, because some UEFI implementation may fail to + boot if there's insufficient space in the EFI variable + storage. + + Using this parameter, you can use the 5KB reservation + in the EFI variable storage. + + However, Use this parameter only if you are really + sure that your UEFI does sane gc and fulfills the spec + otherwise your board may brick. efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT that is to be dynamically loaded by Linux. If there are @@ -1669,10 +1656,6 @@ Kernel parameters very early in the boot process. For early debugging via a serial port see kgdboc_earlycon instead. - elanfreq= [X86-32] - See comment before function elanfreq_setup() in - arch/x86/kernel/cpu/cpufreq/elanfreq.c. - elfcorehdr=[size[KMG]@]offset[KMG] [PPC,SH,X86,S390,EARLY] Specifies physical address of start of kernel core image elf header and optionally the size. Generally @@ -2097,8 +2080,18 @@ Kernel parameters hugetlb_cma= [HW,CMA,EARLY] The size of a CMA area used for allocation of gigantic hugepages. Or using node format, the size of a CMA area per node can be specified. - Format: nn[KMGTPE] or (node format) - <node>:nn[KMGTPE][,<node>:nn[KMGTPE]] + The size can be an absolute value (e.g., 2G) or a + percentage of the total memory or node memory (e.g., 20%). + Percentage-derived sizes are rounded down to a multiple of + the architecture's gigantic hugepage size and may become + zero. + Format: nn[KMGTPE] or nn% or (node format) + <node>:nn[KMGTPE][,<node>:nn[KMGTPE]] or + <node>:nn%[,<node>:nn%] + + The size must be a multiple of the gigantic page size. + When using node format, this applies to each per-node size. + Missaligned values are dropped with a warning. Reserve a CMA area of given size and allocate gigantic hugepages using the CMA allocator. If enabled, the @@ -2245,9 +2238,6 @@ Kernel parameters syscalls, essentially overriding IA32_EMULATION_DEFAULT_DISABLED at boot time. When false, unconditionally disables IA32 emulation. - icn= [HW,ISDN] - Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] - idle= [X86,EARLY] Format: idle=poll, idle=halt, idle=nomwait @@ -2268,6 +2258,29 @@ Kernel parameters idle=nomwait: Disable mwait for CPU C-states + [ARM64,EARLY] + Format: idle=wfi, idle=yield, idle=nop + + idle=wfi: Use the WFI (Wait For Interrupt) hint + instruction in the idle loop. This is the default and + allows the CPU to enter a low-power state until an + interrupt arrives. + + idle=yield: Use the YIELD hint instruction instead of + WFI. CPUs supporting simultaneous multi-threading (SMT), + can continue executing another thread when the current + thread reaches the idle loop. This will make the CPUs + eat more power, but may be useful to get slightly better + performance in some applications, since the CPUs will + not enter a low-power state. + + idle=nop: Do not execute any idle instruction in the + idle loop. This is useful on platforms where WFI + misbehaves, leading to system instability or loss of CPU + state. This will make the CPUs eat more power, but may + give slightly better performance in some applications, + since the CPUs will not enter a low-power state. + idxd.sva= [HW] Format: <bool> Allow force disabling of Shared Virtual Memory (SVA) @@ -2343,6 +2356,12 @@ Kernel parameters Use the canonical format for the binary runtime measurements, instead of host native format. + ima_flush_htable [IMA] + Flush the IMA hash table when deleting all the + staged measurement records, to achieve maximum + memory saving at the cost of having duplicate + records across the staged measurement lists. + ima_hash= [IMA] Format: { md5 | sha1 | rmd160 | sha256 | sha384 | sha512 | ... } @@ -2584,23 +2603,41 @@ Kernel parameters Don't force hardware IOMMU usage when it is not needed. (default). + merge + Do scatter-gather (SG) merging. Implies "force" + (experimental). + + nomerge + Don't do scatter-gather (SG) merging. + biomerge + Do scatter-gather (SG) merging. Implies "force" + (experimental). [same as "merge"] + panic + Always panic when IOMMU overflows. + nopanic - merge - nomerge + Don't panic on IOMMU overflows. + + pt + Use passththrough mode by default + (Equivalent to iommu.passthrough=1) + + nopt + Use translated mode for DMA by default + (Equivalent to iommu.passthrough=0) soft Use software bounce buffering (SWIOTLB) (default for Intel machines). This can be used to prevent the usage of an available hardware IOMMU. - pt - nopt - nobypass [PPC/POWERNV] - Disable IOMMU bypass, using IOMMU for PCI devices. + usedac + Use the DAC on VIA PCI bridge + (default: disable the VIA PCI bridge DAC) - AMD Gart HW IOMMU-specific options: + AMD Gart HW IOMMU-specific options: (CONFIG_GART_IOMMU) <size> Set the size of the remapping area in bytes. @@ -2608,6 +2645,9 @@ Kernel parameters allowed Overwrite iommu off workarounds for specific chipsets + force + Overwrite iommu off workarounds for specific chipsets + fullflush Flush IOMMU on each allocation (default). @@ -2618,21 +2658,16 @@ Kernel parameters Allocate an own aperture over RAM with size 32MB<<order. (default: order=1, i.e. 64MB) - merge - Do scatter-gather (SG) merging. Implies "force" - (experimental). - - nomerge - Don't do scatter-gather (SG) merging. - noaperture Ask the IOMMU not to touch the aperture for AGP. noagp Don't initialize the AGP driver and use full aperture. - panic - Always panic when IOMMU overflows. + iommu= [PPC/POWERNV] + + nobypass + Disable IOMMU bypass, using IOMMU for PCI devices. iommu.forcedac= [ARM64,X86,EARLY] Control IOVA allocation for PCI devices. Format: { "0" | "1" } @@ -2755,7 +2790,6 @@ Kernel parameters Format: <RDP>,<reset>,<pci_scan>,<verbosity> isolcpus= [KNL,SMP,ISOL] Isolate a given set of CPUs from disturbance. - [Deprecated - use cpusets instead] Format: [flag-list,]<cpu-list> Specify one or more CPUs to isolate from disturbances @@ -2780,11 +2814,10 @@ Kernel parameters Isolate from the general SMP balancing and scheduling algorithms. Note that performing domain isolation this way is irreversible: it's not possible to bring back a CPU to - the domains once isolated through isolcpus. It's strongly - advised to use cpusets instead to disable scheduler load - balancing through the "cpuset.sched_load_balance" file. - It offers a much more flexible interface where CPUs can - move in and out of an isolated set anytime. + the domains once isolated through this boot time + configuration. Use cpusets for a dynamic configuration + which can be altered at runtime. For details see + Documentation/admin-guide/cpu-isolation.rst. You can move a process onto or off an "isolated" CPU via the CPU affinity syscalls or cpuset. @@ -3059,7 +3092,7 @@ Kernel parameters Default is 0 (don't ignore, but inject #GP) kvm.eager_page_split= - [KVM,X86] Controls whether or not KVM will try to + [KVM,X86,RISCV] Controls whether or not KVM will try to proactively split all huge pages during dirty logging. Eager page splitting reduces interruptions to vCPU execution by eliminating the write-protection faults @@ -3079,7 +3112,10 @@ Kernel parameters the KVM_CLEAR_DIRTY ioctl, and only for the pages being cleared. - Eager page splitting is only supported when kvm.tdp_mmu=Y. + On x86, eager page splitting is only supported when + kvm.tdp_mmu=Y. + + On RISCV, eager page splitting is supported by default. Default is Y (on). @@ -3458,7 +3494,7 @@ Kernel parameters * SATA link speed limit: 1.5Gbps or 3.0Gbps. - * Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7]. + * Transfer mode: pio[0-6], mwdma[0-4] and udma[0-7]. udma[/][16,25,33,44,66,100,133] notation is also allowed. @@ -3476,7 +3512,7 @@ Kernel parameters * [no]ncqtrim: Enable or disable queued DSM TRIM. - * [no]ncqati: Enable or disable NCQ trim on ATI chipset. + * [no]ncqati: Enable or disable NCQ on ATI chipsets. * [no]trim: Enable or disable (unqueued) TRIM. @@ -3507,11 +3543,9 @@ Kernel parameters * max_sec_128: Set transfer size limit to 128 sectors. - * max_sec_1024: Set or clear transfer size limit to - 1024 sectors. + * max_sec_1024: Set transfer size limit to 1024 sectors. - * max_sec_lba48: Set or clear transfer size limit to - 65535 sectors. + * max_sec_lba48: Set transfer size limit to 65535 sectors. * external: Mark port as external (hotplug-capable). @@ -3794,6 +3828,9 @@ Kernel parameters nobootlog disable boot machine check logging. + print_all + print all machine check logs to the console. + monarchtimeout (number) sets the time in us to wait for other CPUs on machine checks. 0 to disable. @@ -3816,10 +3853,6 @@ Kernel parameters md= [HW] RAID subsystems devices and level See Documentation/admin-guide/md.rst. - mdacon= [MDA] - Format: <first>,<last> - Specifies range of consoles to be captured by the MDA. - mds= [X86,INTEL,EARLY] Control mitigation for the Micro-architectural Data Sampling (MDS) vulnerability. @@ -3993,6 +4026,11 @@ Kernel parameters Note that even when enabled, there are a few cases where the feature is not effective. + mempool_debug [MM] + Enable mempool debugging. This enables element + poison checking when freeing elements back to the + pool. Useful for debugging mempool corruption. + memtest= [KNL,X86,ARM,M68K,PPC,RISCV,EARLY] Enable memtest Format: <integer> default : 0 <disable> @@ -4266,12 +4304,8 @@ Kernel parameters n2= [NET] SDL Inc. RISCom/N2 synchronous serial card - netdev= [NET] Network devices parameters + netdev= [NET] NE2000 ISA network devices parameters Format: <irq>,<io>,<mem_start>,<mem_end>,<name> - Note that mem_start is often overloaded to mean - something different and driver-specific. - This usage is only documented in each driver source - file if at all. netpoll.carrier_timeout= [NET] Specifies amount of time (in seconds) that @@ -4308,13 +4342,6 @@ Kernel parameters Only applies if the softerr mount option is enabled, and the specified value is >= 0. - nfs.enable_ino64= - [NFS] enable 64-bit inode numbers. - If zero, the NFS client will fake up a 32-bit inode - number for the readdir() and stat() syscalls instead - of returning the full 64-bit number. - The default is to return 64-bit inode numbers. - nfs.idmap_cache_timeout= [NFS] set the maximum lifetime for idmapper cache entries. @@ -4437,10 +4464,6 @@ Kernel parameters These settings can be accessed at runtime via the nmi_watchdog and hardlockup_panic sysctls. - no387 [BUGS=X86-32] Tells the kernel to use the 387 maths - emulation library even if a 387 maths coprocessor - is present. - no4lvl [RISCV,EARLY] Disable 4-level and 5-level paging modes. Forces kernel to use 3-level paging instead. @@ -4618,9 +4641,6 @@ Kernel parameters norandmaps Don't use address space randomization. Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space - noreplace-smp [X86-32,SMP] Don't replace SMP instructions - with UP alternatives - noresume [SWSUSP] Disables resume and restores original swap space. @@ -4644,7 +4664,7 @@ Kernel parameters nosmt [KNL,MIPS,PPC,EARLY] Disable symmetric multithreading (SMT). Equivalent to smt=1. - [KNL,LOONGARCH,X86,PPC,S390] Disable symmetric multithreading (SMT). + [KNL,LOONGARCH,X86,ARM64,PPC,S390] Disable symmetric multithreading (SMT). nosmt=force: Force disable SMT, cannot be undone via the sysfs control file. @@ -4841,6 +4861,12 @@ Kernel parameters Adjust the minimal page reporting order. The page reporting is disabled when it exceeds MAX_PAGE_ORDER. + page_reporting.page_reporting_delay_ms= + [KNL] Free page reporting delay in milliseconds + Format: <unsigned integer> + Adjust the delay in milliseconds between free page + reporting intervals. Default is 2000 (2 seconds). + panic= [KNL] Kernel behaviour on panic: delay <timeout> timeout > 0: seconds before rebooting timeout = 0: wait forever @@ -4881,6 +4907,7 @@ Kernel parameters panic_print= Bitmask for printing system info when panic happens. User can chose combination of the following bits: + bit 0: print all tasks info bit 1: print system memory info bit 2: print timer info @@ -4889,10 +4916,16 @@ Kernel parameters bit 5: replay all kernel messages on consoles at the end of panic bit 6: print all CPUs backtrace (if available in the arch) bit 7: print only tasks in uninterruptible (blocked) state - *Be aware* that this option may print a _lot_ of lines, - so there are risks of losing older messages in the log. - Use this option carefully, maybe worth to setup a - bigger log buffer with "log_buf_len" along with this. + + *Be aware* that this option may print a _lot_ of lines. + + There is an increased risk of losing older messages in + the log. Maybe worth to setup a bigger log buffer with + "log_buf_len" along with this. + + Also consider using "printk.console_no_auto_verbose=Y" + if using this along with pstore, to avoid extra delays + due to increased console verbosity during panic. panic_sys_info= A comma separated list of extra information to be dumped on panic. @@ -4907,7 +4940,9 @@ Kernel parameters all_bt: print all CPUs backtrace (if available in the arch) blocked_tasks: print only tasks in uninterruptible (blocked) state - This is a human readable alternative to the 'panic_print' option. + This is a human readable alternative to the 'panic_print' + option above. Please be aware of the caveats using this, + check the 'panic_print' parameter for more details. panic_console_replay When panic happens, replay all kernel messages on @@ -4953,18 +4988,6 @@ Kernel parameters Set to non-zero if a chip is present that snoops speed changes. Disabled by default. - pata_legacy.ht6560a= [HW,LIBATA] - Format: <int> - Set to 1, 2, or 3 for HT 6560A on the primary channel, - the secondary channel, or both channels respectively. - Disabled by default. - - pata_legacy.ht6560b= [HW,LIBATA] - Format: <int> - Set to 1, 2, or 3 for HT 6560B on the primary channel, - the secondary channel, or both channels respectively. - Disabled by default. - pata_legacy.iordy_mask= [HW,LIBATA] Format: <int> IORDY enable mask. Set individual bits to allow IORDY @@ -4977,18 +5000,6 @@ Kernel parameters with the sequence. By default IORDY is allowed across all channels. - pata_legacy.opti82c46x= [HW,LIBATA] - Format: <int> - Set to 1, 2, or 3 for Opti 82c611A on the primary - channel, the secondary channel, or both channels - respectively. Disabled by default. - - pata_legacy.opti82c611a= [HW,LIBATA] - Format: <int> - Set to 1, 2, or 3 for Opti 82c465MV on the primary - channel, the secondary channel, or both channels - respectively. Disabled by default. - pata_legacy.pio_mask= [HW,LIBATA] Format: <int> PIO mode mask for autospeed devices. Set individual @@ -5012,19 +5023,6 @@ Kernel parameters the first port in the list above (0x1f0), and so on. By default all supported ports are probed. - pata_legacy.qdi= [HW,LIBATA] - Format: <int> - Set to non-zero to probe QDI controllers. By default - set to 1 if CONFIG_PATA_QDI_MODULE, 0 otherwise. - - pata_legacy.winbond= [HW,LIBATA] - Format: <int> - Set to non-zero to probe Winbond controllers. Use - the standard I/O port (0x130) if 1, otherwise the - value given is the I/O port to use (typically 0x1b0). - By default set to 1 if CONFIG_PATA_WINBOND_VLB_MODULE, - 0 otherwise. - pata_platform.pio_mask= [HW,LIBATA] Format: <int> Supported PIO mode mask. Set individual bits to allow @@ -5037,8 +5035,6 @@ Kernel parameters the specified number of seconds. This is to be used if your oopses keep scrolling off the screen. - pcbit= [HW,ISDN] - pci=option[,option...] [PCI,EARLY] various PCI subsystem options. Some options herein operate on a specific device @@ -5387,6 +5383,12 @@ Kernel parameters pm_debug_messages [SUSPEND,KNL] Enable suspend/resume debug messages during boot up. + pm.dpm_watchdog_enabled= + [PM] Enable or disable the DPM watchdog. Requires + CONFIG_PM_SLEEP and CONFIG_DPM_WATCHDOG enabled. + Format: <bool> + Default value is set by CONFIG_DPM_WATCHDOG_ENABLED. + pnp.debug=1 [PNP] Enable PNP debug messages (depends on the CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time @@ -5862,13 +5864,13 @@ Kernel parameters use a call_rcu[_hurry]() path. Please note, this is for a normal grace period. - How to enable it: + How to disable it: - echo 1 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp - or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=1" + echo 0 > /sys/module/rcutree/parameters/rcu_normal_wake_from_gp + or pass a boot parameter "rcutree.rcu_normal_wake_from_gp=0" - Default is 1 if num_possible_cpus() <= 16 and it is not explicitly - disabled by the boot parameter passing 0. + Default is 1 if it is not explicitly disabled by the boot parameter + passing 0. rcuscale.gp_async= [KNL] Measure performance of asynchronous @@ -6150,6 +6152,11 @@ Kernel parameters the number of CPUs. For example, -2 selects N (the number of CPUs), -3 selects N+1, and so on. + rcutorture.nwriters= [KNL] + Set number of RCU writers, which must be either + zero or one. For additional writers, use instead + the rcutorture.nfakewriters parameter. + rcutorture.object_debug= [KNL] Enable debug-object double-call_rcu() testing. @@ -6239,6 +6246,15 @@ Kernel parameters and stall_gp_kthread are specified, the kthread is starved first, then the CPU. + rcutorture.stall_only= [KNL] + Shut off all rcutorture kthreads other than the + RCU CPU stall-warning test kthreads. The purpose + of this is to test production applictions' + reactions to CPU stalls, and with minimal + additional overhead. Or you can omit the + stall-warning tests as well and get a heavy + no-op, your choice! + rcutorture.stat_interval= [KNL] Time (s) between statistics printk()s. @@ -6446,9 +6462,9 @@ Kernel parameters reboot= [KNL] Format (x86 or x86_64): [w[arm] | c[old] | h[ard] | s[oft] | g[pio]] | d[efault] \ - [[,]s[mp]#### \ + [[,]s[mp]####] \ [[,]b[ios] | a[cpi] | k[bd] | t[riple] | e[fi] | p[ci]] \ - [[,]f[orce] + [[,]f[orce]] Where reboot_mode is one of warm (soft) or cold (hard) or gpio (prefix with 'panic_' to set mode for panic reboot only), @@ -6778,8 +6794,6 @@ Kernel parameters restrictions other than those given by hardware at the cost of significant additional memory use for tables. - sa1100ir [NET] - See drivers/net/irda/sa1100_ir.c. sched_proxy_exec= [KNL] Enables or disables "proxy execution" style @@ -6910,7 +6924,7 @@ Kernel parameters xtime_lock contention on larger systems, and/or RCU lock contention on all systems with CONFIG_MAXSMP set. Format: { "0" | "1" } - 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1" + 0 -- disable. (may be 1 via CONFIG_CMDLINE="skew_tick=1") 1 -- enable. Note: increases power consumption, thus should only be enabled if running jitter sensitive (HPC/RT) workloads. @@ -6951,7 +6965,7 @@ Kernel parameters apic=verbose is specified. Example: apic=debug show_lapic=all - slab_debug[=options[,slabs][;[options[,slabs]]...] [MM] + slab_debug[=options[,slabs][;[options[,slabs]]...]] [MM] Enabling slab_debug allows one to determine the culprit if slab objects become corrupted. Enabling slab_debug can create guard zones around objects and @@ -7041,17 +7055,6 @@ Kernel parameters take as long as they take. Specifying 300,000 for this value provides a 5-minute timeout. - smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices - smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port - smsc-ircc2.ircc_sir= [HW] SIR base I/O port - smsc-ircc2.ircc_fir= [HW] FIR base I/O port - smsc-ircc2.ircc_irq= [HW] IRQ line - smsc-ircc2.ircc_dma= [HW] DMA channel - smsc-ircc2.ircc_transceiver= [HW] Transceiver type: - 0: Toshiba Satellite 1800 (GP data pin select) - 1: Fast pin select (default) - 2: ATC IRMode - smt= [KNL,MIPS,S390,EARLY] Set the maximum number of threads (logical CPUs) to use per physical CPU on systems capable of symmetric multithreading (SMT). Will @@ -7236,6 +7239,18 @@ Kernel parameters Not specifying this option is equivalent to spec_store_bypass_disable=auto. + split_llc= + [X86,EARLY] Split the LLC N-ways + + When set, the LLC is split this many ways by matching + 'core_id % n'. This is setup before SMP bringup and + used during SMP bringup before it knows the full + topology. If your core count doesn't nicely divide by + the number given, you get to keep the pieces. + + This is mostly a debug feature to emulate multiple LLCs + on hardware that only have a single LLC. + split_lock_detect= [X86] Enable split lock detection or bus lock detection @@ -7414,10 +7429,10 @@ Kernel parameters Set the STI (builtin display/keyboard on the HP-PARISC machines) console (graphic card) which should be used as the initial boot-console. - See also comment in drivers/video/console/sticore.c. + See also comment in drivers/video/sticore.c. sti_font= [HW] - See comment in drivers/video/console/sticore.c. + See comment in drivers/video/sticore.c. stifb= [HW] Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]] @@ -7464,19 +7479,13 @@ Kernel parameters sunrpc.pool_mode= [NFS] - Control how the NFS server code allocates CPUs to - service thread pools. Depending on how many NICs - you have and where their interrupts are bound, this - option will affect which CPUs will do NFS serving. - Note: this parameter cannot be changed while the - NFS server is running. - - auto the server chooses an appropriate mode - automatically using heuristics - global a single global pool contains all CPUs - percpu one pool for each CPU - pernode one pool for each NUMA node (equivalent - to global on non-NUMA machines) + Deprecated. The NFS server now always uses one + service thread pool per NUMA node (equivalent to a + single global pool on non-NUMA machines). All of + the previously accepted values (auto, global, + percpu, pernode) are still accepted for backward + compatibility but are ignored: the mode is always + pernode, and reads always return "pernode". sunrpc.tcp_slot_table_entries= sunrpc.udp_slot_table_entries= @@ -7500,7 +7509,7 @@ Kernel parameters Execution Facility on pSeries. swiotlb= [ARM,PPC,MIPS,X86,S390,EARLY] - Format: { <int> [,<int>] | force | noforce } + Format: { <int> [,<int>] | force | noforce | track_hiwater} <int> -- Number of I/O TLB slabs <int> -- Second integer after comma. Number of swiotlb areas with their own lock. Will be rounded up @@ -7508,6 +7517,8 @@ Kernel parameters force -- force using of bounce buffers even if they wouldn't be automatically used by the kernel noforce -- Never use bounce buffers (for debugging) + track_hiwater -- Track high watermark of swiotlb buffers. + Only available when CONFIG_DEBUG_FS is set. switches= [HW,M68k,EARLY] @@ -7591,6 +7602,10 @@ Kernel parameters See Documentation/admin-guide/mm/transhuge.rst for more details. + tlbi= [X86-64] + Format: {ipi} + ipi: switch to IPI-based TLB flushing + topology= [S390,EARLY] Format: {off | on} Specify if the kernel should make use of the cpu @@ -7888,6 +7903,22 @@ Kernel parameters first trust source as a backend which is initialized successfully during iteration. + trusted.debug= [KEYS] + Format: <bool> + Enable trusted keys debug traces at runtime when + CONFIG_TRUSTED_KEYS_DEBUG=y. + + To make the traces visible after enabling the option, + use trusted.dyndbg='+p' as needed. By convention, + the subsystem uses pr_debug() for these traces. + + SAFETY: The traces can leak sensitive data, so be + cautious before enabling this. They remain inactive + unless this parameter is set this option to a true + value. + + Default: false + trusted.rng= [KEYS] Format: <string> The RNG used to generate key material for trusted keys. @@ -8176,6 +8207,11 @@ Kernel parameters q = USB_QUIRK_FORCE_ONE_CONFIG (Device claims zero configurations, forcing to 1); + r = USB_QUIRK_WINDOWS_CONFIG_REQ_SIZE (Device + fails during initialization when asked for + 9-bytes configuration descriptor request. + Ask for 255-bytes request instead to mirror + Windows' behavior); Example: quirks=0781:5580:bk,0a5c:5834:gij usbhid.mousepoll= |