diff options
| -rw-r--r-- | Documentation/RCU/checklist.rst | 32 | ||||
| -rw-r--r-- | Documentation/RCU/rcu_dereference.rst | 5 | ||||
| -rw-r--r-- | Documentation/RCU/whatisRCU.rst | 19 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.rst | 1 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 489 | ||||
| -rw-r--r-- | include/linux/rcu_sync.h | 1 | ||||
| -rw-r--r-- | include/linux/rcupdate.h | 4 | ||||
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | init/init_task.c | 1 | ||||
| -rw-r--r-- | kernel/context_tracking.c | 4 | ||||
| -rw-r--r-- | kernel/fork.c | 1 | ||||
| -rw-r--r-- | kernel/rcu/Kconfig | 13 | ||||
| -rw-r--r-- | kernel/rcu/rcu.h | 19 | ||||
| -rw-r--r-- | kernel/rcu/rcuscale.c | 6 | ||||
| -rw-r--r-- | kernel/rcu/rcutorture.c | 13 | ||||
| -rw-r--r-- | kernel/rcu/srcutree.c | 24 | ||||
| -rw-r--r-- | kernel/rcu/sync.c | 16 | ||||
| -rw-r--r-- | kernel/rcu/tasks.h | 135 | ||||
| -rw-r--r-- | kernel/rcu/tiny.c | 1 | ||||
| -rw-r--r-- | kernel/rcu/tree.c | 237 | ||||
| -rw-r--r-- | kernel/rcu/tree.h | 20 | ||||
| -rw-r--r-- | kernel/rcu/tree_exp.h | 83 | ||||
| -rw-r--r-- | kernel/rcu/tree_nocb.h | 69 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 52 |
24 files changed, 687 insertions, 560 deletions
diff --git a/Documentation/RCU/checklist.rst b/Documentation/RCU/checklist.rst index 2d42998a89a6..3e6407de231c 100644 --- a/Documentation/RCU/checklist.rst +++ b/Documentation/RCU/checklist.rst @@ -68,7 +68,8 @@ over a rather long period of time, but improvements are always welcome! rcu_read_lock_sched(), or by the appropriate update-side lock. Explicit disabling of preemption (preempt_disable(), for example) can serve as rcu_read_lock_sched(), but is less readable and - prevents lockdep from detecting locking issues. + prevents lockdep from detecting locking issues. Acquiring a + spinlock also enters an RCU read-side critical section. Please note that you *cannot* rely on code known to be built only in non-preemptible kernels. Such code can and will break, @@ -382,16 +383,17 @@ over a rather long period of time, but improvements are always welcome! must use whatever locking or other synchronization is required to safely access and/or modify that data structure. - Do not assume that RCU callbacks will be executed on the same - CPU that executed the corresponding call_rcu() or call_srcu(). - For example, if a given CPU goes offline while having an RCU - callback pending, then that RCU callback will execute on some - surviving CPU. (If this was not the case, a self-spawning RCU - callback would prevent the victim CPU from ever going offline.) - Furthermore, CPUs designated by rcu_nocbs= might well *always* - have their RCU callbacks executed on some other CPUs, in fact, - for some real-time workloads, this is the whole point of using - the rcu_nocbs= kernel boot parameter. + Do not assume that RCU callbacks will be executed on + the same CPU that executed the corresponding call_rcu(), + call_srcu(), call_rcu_tasks(), call_rcu_tasks_rude(), or + call_rcu_tasks_trace(). For example, if a given CPU goes offline + while having an RCU callback pending, then that RCU callback + will execute on some surviving CPU. (If this was not the case, + a self-spawning RCU callback would prevent the victim CPU from + ever going offline.) Furthermore, CPUs designated by rcu_nocbs= + might well *always* have their RCU callbacks executed on some + other CPUs, in fact, for some real-time workloads, this is the + whole point of using the rcu_nocbs= kernel boot parameter. In addition, do not assume that callbacks queued in a given order will be invoked in that order, even if they all are queued on the @@ -444,7 +446,7 @@ over a rather long period of time, but improvements are always welcome! real-time workloads than is synchronize_rcu_expedited(). It is also permissible to sleep in RCU Tasks Trace read-side - critical, which are delimited by rcu_read_lock_trace() and + critical section, which are delimited by rcu_read_lock_trace() and rcu_read_unlock_trace(). However, this is a specialized flavor of RCU, and you should not use it without first checking with its current users. In most cases, you should instead use SRCU. @@ -490,6 +492,12 @@ over a rather long period of time, but improvements are always welcome! since the last time that you passed that same object to call_rcu() (or friends). + CONFIG_RCU_STRICT_GRACE_PERIOD: + combine with KASAN to check for pointers leaked out + of RCU read-side critical sections. This Kconfig + option is tough on both performance and scalability, + and so is limited to four-CPU systems. + __rcu sparse checks: tag the pointer to the RCU-protected data structure with __rcu, and sparse will warn you if you access that diff --git a/Documentation/RCU/rcu_dereference.rst b/Documentation/RCU/rcu_dereference.rst index 659d5913784d..2524dcdadde2 100644 --- a/Documentation/RCU/rcu_dereference.rst +++ b/Documentation/RCU/rcu_dereference.rst @@ -408,7 +408,10 @@ member of the rcu_dereference() to use in various situations: RCU flavors, an RCU read-side critical section is entered using rcu_read_lock(), anything that disables bottom halves, anything that disables interrupts, or anything that disables - preemption. + preemption. Please note that spinlock critical sections + are also implied RCU read-side critical sections, even when + they are preemptible, as they are in kernels built with + CONFIG_PREEMPT_RT=y. 2. If the access might be within an RCU read-side critical section on the one hand, or protected by (say) my_lock on the other, diff --git a/Documentation/RCU/whatisRCU.rst b/Documentation/RCU/whatisRCU.rst index 60ce02475142..872ac665223f 100644 --- a/Documentation/RCU/whatisRCU.rst +++ b/Documentation/RCU/whatisRCU.rst @@ -172,14 +172,25 @@ rcu_read_lock() critical section. Reference counts may be used in conjunction with RCU to maintain longer-term references to data structures. + Note that anything that disables bottom halves, preemption, + or interrupts also enters an RCU read-side critical section. + Acquiring a spinlock also enters an RCU read-side critical + sections, even for spinlocks that do not disable preemption, + as is the case in kernels built with CONFIG_PREEMPT_RT=y. + Sleeplocks do *not* enter RCU read-side critical sections. + rcu_read_unlock() ^^^^^^^^^^^^^^^^^ void rcu_read_unlock(void); This temporal primitives is used by a reader to inform the reclaimer that the reader is exiting an RCU read-side critical - section. Note that RCU read-side critical sections may be nested - and/or overlapping. + section. Anything that enables bottom halves, preemption, + or interrupts also exits an RCU read-side critical section. + Releasing a spinlock also exits an RCU read-side critical section. + + Note that RCU read-side critical sections may be nested and/or + overlapping. synchronize_rcu() ^^^^^^^^^^^^^^^^^ @@ -952,8 +963,8 @@ unfortunately any spinlock in a ``SLAB_TYPESAFE_BY_RCU`` object must be initialized after each and every call to kmem_cache_alloc(), which renders reference-free spinlock acquisition completely unsafe. Therefore, when using ``SLAB_TYPESAFE_BY_RCU``, make proper use of a reference counter. -(Those willing to use a kmem_cache constructor may also use locking, -including cache-friendly sequence locking.) +(Those willing to initialize their locks in a kmem_cache constructor +may also use locking, including cache-friendly sequence locking.) With traditional reference counting -- such as that implemented by the kref library in Linux -- there is typically code that runs when the last diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst index 4410384596a9..e8bdf5e86a9b 100644 --- a/Documentation/admin-guide/kernel-parameters.rst +++ b/Documentation/admin-guide/kernel-parameters.rst @@ -108,6 +108,7 @@ is applicable:: CMA Contiguous Memory Area support 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. EDD BIOS Enhanced Disk Drive Services (EDD) is enabled EFI EFI Partitioning (GPT) is enabled EVM Extended Verification Module diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 31b3a25680d0..94314d0eb301 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -9,7 +9,7 @@ accept_memory=eager can be used to accept all memory at once during boot. - acpi= [HW,ACPI,X86,ARM64,RISCV64] + acpi= [HW,ACPI,X86,ARM64,RISCV64,EARLY] Advanced Configuration and Power Interface Format: { force | on | off | strict | noirq | rsdt | copy_dsdt } @@ -26,7 +26,7 @@ See also Documentation/power/runtime_pm.rst, pci=noacpi - acpi_apic_instance= [ACPI, IOAPIC] + acpi_apic_instance= [ACPI,IOAPIC,EARLY] Format: <int> 2: use 2nd APIC table, if available 1,0: use 1st APIC table @@ -41,7 +41,7 @@ If set to native, use the device's native backlight mode. If set to none, disable the ACPI backlight interface. - acpi_force_32bit_fadt_addr + acpi_force_32bit_fadt_addr [ACPI,EARLY] force FADT to use 32 bit addresses rather than the 64 bit X_* addresses. Some firmware have broken 64 bit addresses for force ACPI ignore these and use @@ -97,7 +97,7 @@ no: ACPI OperationRegions are not marked as reserved, no further checks are performed. - acpi_force_table_verification [HW,ACPI] + acpi_force_table_verification [HW,ACPI,EARLY] Enable table checksum verification during early stage. By default, this is disabled due to x86 early mapping size limitation. @@ -137,7 +137,7 @@ acpi_no_memhotplug [ACPI] Disable memory hotplug. Useful for kdump kernels. - acpi_no_static_ssdt [HW,ACPI] + acpi_no_static_ssdt [HW,ACPI,EARLY] Disable installation of static SSDTs at early boot time By default, SSDTs contained in the RSDT/XSDT will be installed automatically and they will appear under @@ -151,7 +151,7 @@ Ignore the ACPI-based watchdog interface (WDAT) and let a native driver control the watchdog device instead. - acpi_rsdp= [ACPI,EFI,KEXEC] + acpi_rsdp= [ACPI,EFI,KEXEC,EARLY] Pass the RSDP address to the kernel, mostly used on machines running EFI runtime service to boot the second kernel for kdump. @@ -228,10 +228,10 @@ to assume that this machine's pmtimer latches its value and always returns good values. - acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode + acpi_sci= [HW,ACPI,EARLY] ACPI System Control Interrupt trigger mode Format: { level | edge | high | low } - acpi_skip_timer_override [HW,ACPI] + acpi_skip_timer_override [HW,ACPI,EARLY] Recognize and ignore IRQ0/pin2 Interrupt Override. For broken nForce2 BIOS resulting in XT-PIC timer. @@ -266,11 +266,11 @@ behave incorrectly in some ways with respect to system suspend and resume to be ignored (use wisely). - acpi_use_timer_override [HW,ACPI] + acpi_use_timer_override [HW,ACPI,EARLY] Use timer override. For some broken Nvidia NF5 boards that require a timer override, but don't have HPET - add_efi_memmap [EFI; X86] Include EFI memory map in + add_efi_memmap [EFI,X86,EARLY] Include EFI memory map in kernel's map of available physical RAM. agp= [AGP] @@ -307,7 +307,7 @@ do not want to use tracing_snapshot_alloc() as it needs to be done where GFP_KERNEL allocations are allowed. - allow_mismatched_32bit_el0 [ARM64] + allow_mismatched_32bit_el0 [ARM64,EARLY] Allow execve() of 32-bit applications and setting of the PER_LINUX32 personality on systems where only a strict subset of the CPUs support 32-bit EL0. When this @@ -351,7 +351,7 @@ This mode requires kvm-amd.avic=1. (Default when IOMMU HW support is present.) - amd_pstate= [X86] + amd_pstate= [X86,EARLY] disable Do not enable amd_pstate as the default scaling driver for the supported processors @@ -391,7 +391,7 @@ not play well with APC CPU idle - disable it if you have APC and your system crashes randomly. - apic= [APIC,X86] Advanced Programmable Interrupt Controller + apic= [APIC,X86,EARLY] Advanced Programmable Interrupt Controller Change the output verbosity while booting Format: { quiet (default) | verbose | debug } Change the amount of debugging information output @@ -401,7 +401,7 @@ Format: apic=driver_name Examples: apic=bigsmp - apic_extnmi= [APIC,X86] External NMI delivery setting + apic_extnmi= [APIC,X86,EARLY] External NMI delivery setting Format: { bsp (default) | all | none } bsp: External NMI is delivered only to CPU 0 all: External NMIs are broadcast to all CPUs as a @@ -508,21 +508,22 @@ bert_disable [ACPI] Disable BERT OS support on buggy BIOSes. - bgrt_disable [ACPI][X86] + bgrt_disable [ACPI,X86,EARLY] Disable BGRT to avoid flickering OEM logo. blkdevparts= Manual partition parsing of block device(s) for embedded devices based on command line input. See Documentation/block/cmdline-partition.rst - boot_delay= Milliseconds to delay each printk during boot. + boot_delay= [KNL,EARLY] + Milliseconds to delay each printk during boot. Only works if CONFIG_BOOT_PRINTK_DELAY is enabled, and you may also have to specify "lpj=". Boot_delay values larger than 10 seconds (10000) are assumed erroneous and ignored. Format: integer - bootconfig [KNL] + bootconfig [KNL,EARLY] Extended command line options can be added to an initrd and this will cause the kernel to look for it. @@ -557,7 +558,7 @@ trust validation. format: { id:<keyid> | builtin } - cca= [MIPS] Override the kernel pages' cache coherency + cca= [MIPS,EARLY] Override the kernel pages' cache coherency algorithm. Accepted values range from 0 to 7 inclusive. See arch/mips/include/asm/pgtable-bits.h for platform specific values (SB1, Loongson3 and @@ -672,7 +673,7 @@ [X86-64] hpet,tsc clocksource.arm_arch_timer.evtstrm= - [ARM,ARM64] + [ARM,ARM64,EARLY] Format: <bool> Enable/disable the eventstream feature of the ARM architected timer so that code using WFE-based polling @@ -702,7 +703,7 @@ 10 seconds when built into the kernel. cma=nn[MG]@[start[MG][-end[MG]]] - [KNL,CMA] + [KNL,CMA,EARLY] Sets the size of kernel global memory area for contiguous memory allocations and optionally the placement constraint by the physical address range of @@ -711,7 +712,7 @@ kernel/dma/contiguous.c cma_pernuma=nn[MG] - [KNL,CMA] + [KNL,CMA,EARLY] Sets the size of kernel per-numa memory area for contiguous memory allocations. A value of 0 disables per-numa CMA altogether. And If this option is not @@ -722,7 +723,7 @@ they will fallback to the global default memory area. numa_cma=<node>:nn[MG][,<node>:nn[MG]] - [KNL,CMA] + [KNL,CMA,EARLY] Sets the size of kernel numa memory area for contiguous memory allocations. It will reserve CMA area for the specified node. @@ -739,7 +740,7 @@ a hypervisor. Default: yes - coherent_pool=nn[KMG] [ARM,KNL] + coherent_pool=nn[KMG] [ARM,KNL,EARLY] Sets the size of memory pool for coherent, atomic dma allocations, by default set to 256K. @@ -757,7 +758,7 @@ condev= [HW,S390] console device conmode= - con3215_drop= [S390] 3215 console drop mode. + con3215_drop= [S390,EARLY] 3215 console drop mode. Format: y|n|Y|N|1|0 When set to true, drop data on the 3215 console when the console buffer is full. In this case the @@ -863,7 +864,7 @@ kernel before the cpufreq driver probes. cpu_init_udelay=N - [X86] Delay for N microsec between assert and de-assert + [X86,EARLY] Delay for N microsec between assert and de-assert of APIC INIT to start processors. This delay occurs on every CPU online, such as boot, and resume from suspend. Default: 10000 @@ -883,7 +884,7 @@ kernel more unstable. crashkernel=size[KMG][@offset[KMG]] - [KNL] Using kexec, Linux can switch to a 'crash kernel' + [KNL,EARLY] Using kexec, Linux can switch to a 'crash kernel' upon panic. This parameter reserves the physical memory region [offset, offset + size] for that kernel image. If '@offset' is omitted, then a suitable offset @@ -954,10 +955,10 @@ Format: <port#>,<type> See also Documentation/input/devices/joystick-parport.rst - debug [KNL] Enable kernel debugging (events log level). + debug [KNL,EARLY] Enable kernel debugging (events log level). debug_boot_weak_hash - [KNL] Enable printing [hashed] pointers early in the + [KNL,EARLY] Enable printing [hashed] pointers early in the boot sequence. If enabled, we use a weak hash instead of siphash to hash pointers. Use this option if you are seeing instances of '(___ptrval___)') and need to see a @@ -974,10 +975,10 @@ will print _a_lot_ more information - normally only useful to lockdep developers. - debug_objects [KNL] Enable object debugging + debug_objects [KNL,EARLY] Enable object debugging debug_guardpage_minorder= - [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this + [KNL,EARLY] When CONFIG_DEBUG_PAGEALLOC is set, this parameter allows control of the order of pages that will be intentionally kept free (and hence protected) by the buddy allocator. Bigger value increase the probability @@ -996,7 +997,7 @@ help tracking down these problems. debug_pagealloc= - [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this parameter + [KNL,EARLY] When CONFIG_DEBUG_PAGEALLOC is set, this parameter enables the feature at boot time. By default, it is disabled and the system will work mostly the same as a kernel built without CONFIG_DEBUG_PAGEALLOC. @@ -1004,8 +1005,8 @@ 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. + debugfs= [KNL,EARLY] This parameter enables what is exposed to + userspace and debugfs internal clients. Format: { on, no-mount, off } on: All functions are enabled. no-mount: @@ -1084,7 +1085,7 @@ dhash_entries= [KNL] Set number of hash buckets for dentry cache. - disable_1tb_segments [PPC] + disable_1tb_segments [PPC,EARLY] Disables the use of 1TB hash page table segments. This causes the kernel to fall back to 256MB segments which can be useful when debugging issues that require an SLB @@ -1093,7 +1094,7 @@ disable= [IPV6] See Documentation/networking/ipv6.rst. - disable_radix [PPC] + disable_radix [PPC,EARLY] Disable RADIX MMU mode on POWER9 disable_tlbie [PPC] @@ -1109,25 +1110,25 @@ causing system reset or hang due to sending INIT from AP to BSP. - disable_ddw [PPC/PSERIES] + disable_ddw [PPC/PSERIES,EARLY] Disable Dynamic DMA Window support. Use this to workaround buggy firmware. disable_ipv6= [IPV6] See Documentation/networking/ipv6.rst. - disable_mtrr_cleanup [X86] + disable_mtrr_cleanup [X86,EARLY] The kernel tries to adjust MTRR layout from continuous to discrete, to make X server driver able to add WB entry later. This parameter disables that. - disable_mtrr_trim [X86, Intel and AMD only] + disable_mtrr_trim [X86, Intel and AMD only,EARLY] By default the kernel will trim any uncacheable memory out of your available memory pool based on MTRR settings. This parameter disables that behavior, possibly causing your machine to run very slowly. - disable_timer_pin_1 [X86] + disable_timer_pin_1 [X86,EARLY] Disable PIN 1 of APIC timer Can be useful to work around chipset bugs. @@ -1177,7 +1178,7 @@ dscc4.setup= [NET] - dt_cpu_ftrs= [PPC] + dt_cpu_ftrs= [PPC,EARLY] Format: {"off" | "known"} Control how the dt_cpu_ftrs device-tree binding is used for CPU feature discovery and setup (if it @@ -1197,12 +1198,12 @@ Documentation/admin-guide/dynamic-debug-howto.rst for details. - early_ioremap_debug [KNL] + early_ioremap_debug [KNL,EARLY] Enable debug messages in early_ioremap support. This is useful for tracking down temporary early mappings which are not unmapped. - earlycon= [KNL] Output early console device and options. + earlycon= [KNL,EARLY] Output early console device and options. When used with no options, the early console is determined by stdout-path property in device tree's @@ -1338,7 +1339,7 @@ address must be provided, and the serial port must already be setup and configured. - earlyprintk= [X86,SH,ARM,M68k,S390] + earlyprintk= [X86,SH,ARM,M68k,S390,UM,EARLY] earlyprintk=vga earlyprintk=sclp earlyprintk=xen @@ -1396,7 +1397,7 @@ edd= [EDD] Format: {"off" | "on" | "skip[mbr]"} - efi= [EFI] + efi= [EFI,EARLY] Format: { "debug", "disable_early_pci_dma", "nochunk", "noruntime", "nosoftreserve", "novamap", "no_disable_early_pci_dma" } @@ -1417,13 +1418,13 @@ no_disable_early_pci_dma: Leave the busmaster bit set on all PCI bridges while in the EFI boot stub - efi_no_storage_paranoia [EFI; X86] + 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. - efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86] + efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI,X86,EARLY] Add arbitrary attribute to specific memory range by updating original EFI memory map. Region of memory which aa attribute is added to is @@ -1454,7 +1455,7 @@ eisa_irq_edge= [PARISC,HW] See header of drivers/parisc/eisa.c. - ekgdboc= [X86,KGDB] Allow early kernel console debugging + ekgdboc= [X86,KGDB,EARLY] Allow early kernel console debugging Format: ekgdboc=kbd This is designed to be used in conjunction with @@ -1469,13 +1470,13 @@ See comment before function elanfreq_setup() in arch/x86/kernel/cpu/cpufreq/elanfreq.c. - elfcorehdr=[size[KMG]@]offset[KMG] [PPC,SH,X86,S390] + 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 kexec loader will pass this option to capture kernel. See Documentation/admin-guide/kdump/kdump.rst for details. - enable_mtrr_cleanup [X86] + enable_mtrr_cleanup [X86,EARLY] The kernel tries to adjust MTRR layout from continuous to discrete, to make X server driver able to add WB entry later. This parameter enables that. @@ -1508,7 +1509,7 @@ Permit 'security.evm' to be updated regardless of current integrity status. - early_page_ext [KNL] Enforces page_ext initialization to earlier + early_page_ext [KNL,EARLY] Enforces page_ext initialization to earlier stages so cover more early boot allocations. Please note that as side effect some optimizations might be disabled to achieve that (e.g. parallelized @@ -1600,7 +1601,7 @@ can be changed at run time by the max_graph_depth file in the tracefs tracing directory. default: 0 (no limit) - fw_devlink= [KNL] Create device links between consumer and supplier + fw_devlink= [KNL,EARLY] Create device links between consumer and supplier devices by scanning the firmware to infer the consumer/supplier relationships. This feature is especially useful when drivers are loaded as modules as @@ -1619,12 +1620,12 @@ rpm -- Like "on", but also use to order runtime PM. fw_devlink.strict=<bool> - [KNL] Treat all inferred dependencies as mandatory + [KNL,EARLY] Treat all inferred dependencies as mandatory dependencies. This only applies for fw_devlink=on|rpm. Format: <bool> fw_devlink.sync_state = - [KNL] When all devices that could probe have finished + [KNL,EARLY] When all devices that could probe have finished probing, this parameter controls what to do with devices that haven't yet received their sync_state() calls. @@ -1645,12 +1646,12 @@ gamma= [HW,DRM] - gart_fix_e820= [X86-64] disable the fix e820 for K8 GART + gart_fix_e820= [X86-64,EARLY] disable the fix e820 for K8 GART Format: off | on default: on gather_data_sampling= - [X86,INTEL] Control the Gather Data Sampling (GDS) + [X86,INTEL,EARLY] Control the Gather Data Sampling (GDS) mitigation. Gather Data Sampling is a hardware vulnerability which @@ -1748,7 +1749,7 @@ (that will set all pages holding image data during restoration read-only). - highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact + highmem=nn[KMG] [KNL,BOOT,EARLY] forces the highmem zone to have an exact size of <nn>. This works even on boxes that have no highmem otherwise. This also works to reduce highmem size on bigger boxes. @@ -1759,7 +1760,7 @@ hlt [BUGS=ARM,SH] - hostname= [KNL] Set the hostname (aka UTS nodename). + hostname= [KNL,EARLY] Set the hostname (aka UTS nodename). Format: <string> This allows setting the system's hostname during early startup. This sets the name returned by gethostname. @@ -1804,7 +1805,7 @@ Documentation/admin-guide/mm/hugetlbpage.rst. Format: size[KMG] - hugetlb_cma= [HW,CMA] The size of a CMA area used for allocation + 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) @@ -1850,9 +1851,10 @@ If specified, z/VM IUCV HVC accepts connections from listed z/VM user IDs only. - hv_nopvspin [X86,HYPER_V] Disables the paravirt spinlock optimizations - which allow the hypervisor to 'idle' the - guest on lock contention. + hv_nopvspin [X86,HYPER_V,EARLY] + Disables the paravirt spinlock optimizations + which allow the hypervisor to 'idle' the guest + on lock contention. i2c_bus= [HW] Override the default board specific I2C bus speed or register an additional I2C bus that is not @@ -1917,7 +1919,7 @@ Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] - idle= [X86] + idle= [X86,EARLY] Format: idle=poll, idle=halt, idle=nomwait Poll forces a polling idle loop that can slightly improve the performance of waking up a idle CPU, but @@ -1973,7 +1975,7 @@ mode generally follows that for the NaN encoding, except where unsupported by hardware. - ignore_loglevel [KNL] + ignore_loglevel [KNL,EARLY] Ignore loglevel setting - this will print /all/ kernel messages to the console. Useful for debugging. We also add it as printk module parameter, so users @@ -2091,21 +2093,21 @@ unpacking being completed before device_ and late_ initcalls. - initrd= [BOOT] Specify the location of the initial ramdisk + initrd= [BOOT,EARLY] Specify the location of the initial ramdisk - initrdmem= [KNL] Specify a physical address and size from which to + initrdmem= [KNL,EARLY] Specify a physical address and size from which to load the initrd. If an initrd is compiled in or specified in the bootparams, it takes priority over this setting. Format: ss[KMG],nn[KMG] Default is 0, 0 - init_on_alloc= [MM] Fill newly allocated pages and heap objects with + init_on_alloc= [MM,EARLY] Fill newly allocated pages and heap objects with zeroes. Format: 0 | 1 Default set by CONFIG_INIT_ON_ALLOC_DEFAULT_ON. - init_on_free= [MM] Fill freed pages and heap objects with zeroes. + init_on_free= [MM,EARLY] Fill freed pages and heap objects with zeroes. Format: 0 | 1 Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON. @@ -2161,7 +2163,7 @@ 0 disables intel_idle and fall back on acpi_idle. 1 to 9 specify maximum depth of C-state. - intel_pstate= [X86] + intel_pstate= [X86,EARLY] disable Do not enable intel_pstate as the default scaling driver for the supported processors @@ -2205,7 +2207,7 @@ Allow per-logical-CPU P-State performance control limits using cpufreq sysfs interface - intremap= [X86-64, Intel-IOMMU] + intremap= [X86-64,Intel-IOMMU,EARLY] on enable Interrupt Remapping (default) off disable Interrupt Remapping nosid disable Source ID checking @@ -2217,7 +2219,7 @@ strict regions from userspace. relaxed - iommu= [X86] + iommu= [X86,EARLY] off force noforce @@ -2232,7 +2234,7 @@ nobypass [PPC/POWERNV] Disable IOMMU bypass, using IOMMU for PCI devices. - iommu.forcedac= [ARM64, X86] Control IOVA allocation for PCI devices. + iommu.forcedac= [ARM64,X86,EARLY] Control IOVA allocation for PCI devices. Format: { "0" | "1" } 0 - Try to allocate a 32-bit DMA address first, before falling back to the full range if needed. @@ -2240,7 +2242,7 @@ forcing Dual Address Cycle for PCI cards supporting greater than 32-bit addressing. - iommu.strict= [ARM64, X86, S390] Configure TLB invalidation behaviour + iommu.strict= [ARM64,X86,S390,EARLY] Configure TLB invalidation behaviour Format: { "0" | "1" } 0 - Lazy mode. Request that DMA unmap operations use deferred @@ -2256,7 +2258,7 @@ legacy driver-specific options takes precedence. iommu.passthrough= - [ARM64, X86] Configure DMA to bypass the IOMMU by default. + [ARM64,X86,EARLY] Configure DMA to bypass the IOMMU by default. Format: { "0" | "1" } 0 - Use IOMMU translation for DMA. 1 - Bypass the IOMMU for DMA. @@ -2266,7 +2268,7 @@ See comment before marvel_specify_io7 in arch/alpha/kernel/core_marvel.c. - io_delay= [X86] I/O delay method + io_delay= [X86,EARLY] I/O delay method 0x80 Standard port 0x80 based delay 0xed @@ -2279,28 +2281,28 @@ ip= [IP_PNP] See Documentation/admin-guide/nfs/nfsroot.rst. - ipcmni_extend [KNL] Extend the maximum number of unique System V + ipcmni_extend [KNL,EARLY] Extend the maximum number of unique System V IPC identifiers from 32,768 to 16,777,216. irqaffinity= [SMP] Set the default irq affinity mask The argument is a cpu list, as described above. irqchip.gicv2_force_probe= - [ARM, ARM64] + [ARM,ARM64,EARLY] Format: <bool> Force the kernel to look for the second 4kB page of a GICv2 controller even if the memory range exposed by the device tree is too small. irqchip.gicv3_nolpi= - [ARM, ARM64] + [ARM,ARM64,EARLY] Force the kernel to ignore the availability of LPIs (and by consequence ITSs). Intended for system that use the kernel as a bootloader, and thus want to let secondary kernels in charge of setting up LPIs. - irqchip.gicv3_pseudo_nmi= [ARM64] + irqchip.gicv3_pseudo_nmi= [ARM64,EARLY] Enables support for pseudo-NMIs in the kernel. This requires the kernel to be built with CONFIG_ARM64_PSEUDO_NMI. @@ -2445,7 +2447,7 @@ parameter KASAN will print report only for the first invalid access. - keep_bootcon [KNL] + keep_bootcon [KNL,EARLY] Do not unregister boot console at start. This is only useful for debugging when something happens in the window between unregistering the boot console and initializing @@ -2453,7 +2455,7 @@ keepinitrd [HW,ARM] See retain_initrd. - kernelcore= [KNL,X86,IA-64,PPC] + kernelcore= [KNL,X86,IA-64,PPC,EARLY] Format: nn[KMGTPE] | nn% | "mirror" This parameter specifies the amount of memory usable by the kernel for non-movable allocations. The requested @@ -2478,7 +2480,7 @@ for Movable pages. "nn[KMGTPE]", "nn%", and "mirror" are exclusive, so you cannot specify multiple forms. - kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port. + kgdbdbgp= [KGDB,HW,EARLY] kgdb over EHCI usb debug port. Format: <Controller#>[,poll interval] The controller # is the number of the ehci usb debug port as it is probed via PCI. The poll interval is @@ -2499,7 +2501,7 @@ kms, kbd format: kms,kbd kms, kbd and serial format: kms,kbd,<ser_dev>[,baud] - kgdboc_earlycon= [KGDB,HW] + kgdboc_earlycon= [KGDB,HW,EARLY] If the boot console provides the ability to read characters and can work in polling mode, you can use this parameter to tell kgdb to use it as a backend @@ -2514,14 +2516,14 @@ blank and the first boot console that implements</ |