diff options
Diffstat (limited to 'Documentation/admin-guide')
22 files changed, 358 insertions, 207 deletions
diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index 5f502bf68fbc..ff456871bf4b 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -92,6 +92,13 @@ Brief summary of control files. memory.oom_control set/show oom controls. memory.numa_stat show the number of memory usage per numa node + memory.kmem.limit_in_bytes Deprecated knob to set and read the kernel + memory hard limit. Kernel hard limit is not + supported since 5.16. Writing any value to + do file will not have any effect same as if + nokmem kernel parameter was specified. + Kernel memory is still charged and reported + by memory.kmem.usage_in_bytes. memory.kmem.usage_in_bytes show current kernel memory allocation memory.kmem.failcnt show the number of kernel memory usage hits limits diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index b26b5274eaaf..3f081459a5be 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -364,6 +364,13 @@ constraint, a threaded controller must be able to handle competition between threads in a non-leaf cgroup and its child cgroups. Each threaded controller defines how such competitions are handled. +Currently, the following controllers are threaded and can be enabled +in a threaded cgroup:: + +- cpu +- cpuset +- perf_event +- pids [Un]populated Notification -------------------------- @@ -2023,7 +2030,7 @@ IO Priority ~~~~~~~~~~~ A single attribute controls the behavior of the I/O priority cgroup policy, -namely the blkio.prio.class attribute. The following values are accepted for +namely the io.prio.class attribute. The following values are accepted for that attribute: no-change @@ -2052,9 +2059,11 @@ The following numerical values are associated with the I/O priority policies: +----------------+---+ | no-change | 0 | +----------------+---+ -| rt-to-be | 2 | +| promote-to-rt | 1 | ++----------------+---+ +| restrict-to-be | 2 | +----------------+---+ -| all-to-idle | 3 | +| idle | 3 | +----------------+---+ The numerical value that corresponds to each I/O priority class is as follows: @@ -2074,7 +2083,7 @@ The algorithm to set the I/O priority class for a request is as follows: - If I/O priority class policy is promote-to-rt, change the request I/O priority class to IOPRIO_CLASS_RT and change the request I/O priority level to 4. -- If I/O priorityt class is not promote-to-rt, translate the I/O priority +- If I/O priority class policy is not promote-to-rt, translate the I/O priority class policy into a number, then change the request I/O priority class into the maximum of the I/O priority class policy number and the numerical I/O priority class. @@ -2226,6 +2235,49 @@ Cpuset Interface Files Its value will be affected by memory nodes hotplug events. + cpuset.cpus.exclusive + A read-write multiple values file which exists on non-root + cpuset-enabled cgroups. + + It lists all the exclusive CPUs that are allowed to be used + to create a new cpuset partition. Its value is not used + unless the cgroup becomes a valid partition root. See the + "cpuset.cpus.partition" section below for a description of what + a cpuset partition is. + + When the cgroup becomes a partition root, the actual exclusive + CPUs that are allocated to that partition are listed in + "cpuset.cpus.exclusive.effective" which may be different + from "cpuset.cpus.exclusive". If "cpuset.cpus.exclusive" + has previously been set, "cpuset.cpus.exclusive.effective" + is always a subset of it. + + Users can manually set it to a value that is different from + "cpuset.cpus". The only constraint in setting it is that the + list of CPUs must be exclusive with respect to its sibling. + + For a parent cgroup, any one of its exclusive CPUs can only + be distributed to at most one of its child cgroups. Having an + exclusive CPU appearing in two or more of its child cgroups is + not allowed (the exclusivity rule). A value that violates the + exclusivity rule will be rejected with a write error. + + The root cgroup is a partition root and all its available CPUs + are in its exclusive CPU set. + + cpuset.cpus.exclusive.effective + A read-only multiple values file which exists on all non-root + cpuset-enabled cgroups. + + This file shows the effective set of exclusive CPUs that + can be used to create a partition root. The content of this + file will always be a subset of "cpuset.cpus" and its parent's + "cpuset.cpus.exclusive.effective" if its parent is not the root + cgroup. It will also be a subset of "cpuset.cpus.exclusive" + if it is set. If "cpuset.cpus.exclusive" is not set, it is + treated to have an implicit value of "cpuset.cpus" in the + formation of local partition. + cpuset.cpus.partition A read-write single value file which exists on non-root cpuset-enabled cgroups. This flag is owned by the parent cgroup @@ -2239,26 +2291,41 @@ Cpuset Interface Files "isolated" Partition root without load balancing ========== ===================================== - The root cgroup is always a partition root and its state - cannot be changed. All other non-root cgroups start out as - "member". + A cpuset partition is a collection of cpuset-enabled cgroups with + a partition root at the top of the hierarchy and its descendants + except those that are separate partition roots themselves and + their descendants. A partition has exclusive access to the + set of exclusive CPUs allocated to it. Other cgroups outside + of that partition cannot use any CPUs in that set. + + There are two types of partitions - local and remote. A local + partition is one whose parent cgroup is also a valid partition + root. A remote partition is one whose parent cgroup is not a + valid partition root itself. Writing to "cpuset.cpus.exclusive" + is optional for the creation of a local partition as its + "cpuset.cpus.exclusive" file will assume an implicit value that + is the same as "cpuset.cpus" if it is not set. Writing the + proper "cpuset.cpus.exclusive" values down the cgroup hierarchy + before the target partition root is mandatory for the creation + of a remote partition. + + Currently, a remote partition cannot be created under a local + partition. All the ancestors of a remote partition root except + the root cgroup cannot be a partition root. + + The root cgroup is always a partition root and its state cannot + be changed. All other non-root cgroups start out as "member". When set to "root", the current cgroup is the root of a new - partition or scheduling domain that comprises itself and all - its descendants except those that are separate partition roots - themselves and their descendants. + partition or scheduling domain. The set of exclusive CPUs is + determined by the value of its "cpuset.cpus.exclusive.effective". - When set to "isolated", the CPUs in that partition root will + When set to "isolated", the CPUs in that partition will be in an isolated state without any load balancing from the scheduler. Tasks placed in such a partition with multiple CPUs should be carefully distributed and bound to each of the individual CPUs for optimal performance. - The value shown in "cpuset.cpus.effective" of a partition root - is the CPUs that the partition root can dedicate to a potential - new child partition root. The new child subtracts available - CPUs from its parent "cpuset.cpus.effective". - A partition root ("root" or "isolated") can be in one of the two possible states - valid or invalid. An invalid partition root is in a degraded state where some state information may @@ -2281,37 +2348,33 @@ Cpuset Interface Files In the case of an invalid partition root, a descriptive string on why the partition is invalid is included within parentheses. - For a partition root to become valid, the following conditions + For a local partition root to be valid, the following conditions must be met. - 1) The "cpuset.cpus" is exclusive with its siblings , i.e. they - are not shared by any of its siblings (exclusivity rule). - 2) The parent cgroup is a valid partition root. - 3) The "cpuset.cpus" is not empty and must contain at least - one of the CPUs from parent's "cpuset.cpus", i.e. they overlap. - 4) The "cpuset.cpus.effective" cannot be empty unless there is + 1) The parent cgroup is a valid partition root. + 2) The "cpuset.cpus.exclusive.effective" file cannot be empty, + though it may contain offline CPUs. + 3) The "cpuset.cpus.effective" cannot be empty unless there is no task associated with this partition. - External events like hotplug or changes to "cpuset.cpus" can - cause a valid partition root to become invalid and vice versa. - Note that a task cannot be moved to a cgroup with empty - "cpuset.cpus.effective". + For a remote partition root to be valid, all the above conditions + except the first one must be met. - For a valid partition root with the sibling cpu exclusivity - rule enabled, changes made to "cpuset.cpus" that violate the - exclusivity rule will invalidate the partition as well as its - sibling partitions with conflicting cpuset.cpus values. So - care must be taking in changing "cpuset.cpus". + External events like hotplug or changes to "cpuset.cpus" or + "cpuset.cpus.exclusive" can cause a valid partition root to + become invalid and vice versa. Note that a task cannot be + moved to a cgroup with empty "cpuset.cpus.effective". A valid non-root parent partition may distribute out all its CPUs - to its child partitions when there is no task associated with it. + to its child local partitions when there is no task associated + with it. - Care must be taken to change a valid partition root to - "member" as all its child partitions, if present, will become + Care must be taken to change a valid partition root to "member" + as all its child local partitions, if present, will become invalid causing disruption to tasks running in those child partitions. These inactivated partitions could be recovered if their parent is switched back to a partition root with a proper - set of "cpuset.cpus". + value in "cpuset.cpus" or "cpuset.cpus.exclusive". Poll and inotify events are triggered whenever the state of "cpuset.cpus.partition" changes. That includes changes caused @@ -2321,6 +2384,11 @@ Cpuset Interface Files to "cpuset.cpus.partition" without the need to do continuous polling. + A user can pre-configure certain CPUs to an isolated state + with load balancing disabled at boot time with the "isolcpus" + kernel boot command line option. If those CPUs are to be put + into a partition, they have to be used in an isolated partition. + Device controller ----------------- diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst index 0b3d39c610d9..0c526dac8428 100644 --- a/Documentation/admin-guide/dynamic-debug-howto.rst +++ b/Documentation/admin-guide/dynamic-debug-howto.rst @@ -259,7 +259,7 @@ Debug Messages at Module Initialization Time When ``modprobe foo`` is called, modprobe scans ``/proc/cmdline`` for ``foo.params``, strips ``foo.``, and passes them to the kernel along with -params given in modprobe args or ``/etc/modprob.d/*.conf`` files, +params given in modprobe args or ``/etc/modprobe.d/*.conf`` files, in the following order: 1. parameters given via ``/etc/modprobe.d/*.conf``:: diff --git a/Documentation/admin-guide/efi-stub.rst b/Documentation/admin-guide/efi-stub.rst index b24e7c40d832..090f3a185e18 100644 --- a/Documentation/admin-guide/efi-stub.rst +++ b/Documentation/admin-guide/efi-stub.rst @@ -15,7 +15,7 @@ between architectures is in drivers/firmware/efi/libstub. For arm64, there is no compressed kernel support, so the Image itself masquerades as a PE/COFF image and the EFI stub is linked into the -kernel. The arm64 EFI stub lives in arch/arm64/kernel/efi-entry.S +kernel. The arm64 EFI stub lives in drivers/firmware/efi/libstub/arm64.c and drivers/firmware/efi/libstub/arm64-stub.c. By using the EFI boot stub it's possible to boot a Linux kernel diff --git a/Documentation/admin-guide/hw-vuln/mds.rst b/Documentation/admin-guide/hw-vuln/mds.rst index 48ca0bd85604..48c7b0b72aed 100644 --- a/Documentation/admin-guide/hw-vuln/mds.rst +++ b/Documentation/admin-guide/hw-vuln/mds.rst @@ -102,9 +102,19 @@ The possible values in this file are: * - 'Vulnerable' - The processor is vulnerable, but no mitigation enabled * - 'Vulnerable: Clear CPU buffers attempted, no microcode' - - The processor is vulnerable but microcode is not updated. - - The mitigation is enabled on a best effort basis. See :ref:`vmwerv` + - The processor is vulnerable but microcode is not updated. The + mitigation is enabled on a best effort basis. + + If the processor is vulnerable but the availability of the microcode + based mitigation mechanism is not advertised via CPUID, the kernel + selects a best effort mitigation mode. This mode invokes the mitigation + instructions without a guarantee that they clear the CPU buffers. + + This is done to address virtualization scenarios where the host has the + microcode update applied, but the hypervisor is not yet updated to + expose the CPUID to the guest. If the host has updated microcode the + protection takes effect; otherwise a few CPU cycles are wasted + pointlessly. * - 'Mitigation: Clear CPU buffers' - The processor is vulnerable and the CPU buffer clearing mitigation is enabled. @@ -119,24 +129,6 @@ to the above information: 'SMT Host state unknown' Kernel runs in a VM, Host SMT state unknown ======================== ============================================ -.. _vmwerv: - -Best effort mitigation mode -^^^^^^^^^^^^^^^^^^^^^^^^^^^ - - If the processor is vulnerable, but the availability of the microcode based - mitigation mechanism is not advertised via CPUID the kernel selects a best - effort mitigation mode. This mode invokes the mitigation instructions - without a guarantee that they clear the CPU buffers. - - This is done to address virtualization scenarios where the host has the - microcode update applied, but the hypervisor is not yet updated to expose - the CPUID to the guest. If the host has updated microcode the protection - takes effect otherwise a few cpu cycles are wasted pointlessly. - - The state in the mds sysfs file reflects this situation accordingly. - - Mitigation mechanism ------------------------- diff --git a/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst b/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst index c98fd11907cc..1302fd1b55e8 100644 --- a/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst +++ b/Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst @@ -225,8 +225,19 @@ The possible values in this file are: * - 'Vulnerable' - The processor is vulnerable, but no mitigation enabled * - 'Vulnerable: Clear CPU buffers attempted, no microcode' - - The processor is vulnerable, but microcode is not updated. The + - The processor is vulnerable but microcode is not updated. The mitigation is enabled on a best effort basis. + + If the processor is vulnerable but the availability of the microcode + based mitigation mechanism is not advertised via CPUID, the kernel + selects a best effort mitigation mode. This mode invokes the mitigation + instructions without a guarantee that they clear the CPU buffers. + + This is done to address virtualization scenarios where the host has the + microcode update applied, but the hypervisor is not yet updated to + expose the CPUID to the guest. If the host has updated microcode the + protection takes effect; otherwise a few CPU cycles are wasted + pointlessly. * - 'Mitigation: Clear CPU buffers' - The processor is vulnerable and the CPU buffer clearing mitigation is enabled. diff --git a/Documentation/admin-guide/hw-vuln/srso.rst b/Documentation/admin-guide/hw-vuln/srso.rst index b6cfb51cb0b4..e715bfc09879 100644 --- a/Documentation/admin-guide/hw-vuln/srso.rst +++ b/Documentation/admin-guide/hw-vuln/srso.rst @@ -46,12 +46,22 @@ The possible values in this file are: The processor is not vulnerable - * 'Vulnerable: no microcode': +* 'Vulnerable': + + The processor is vulnerable and no mitigations have been applied. + + * 'Vulnerable: No microcode': The processor is vulnerable, no microcode extending IBPB functionality to address the vulnerability has been applied. - * 'Mitigation: microcode': + * 'Vulnerable: Safe RET, no microcode': + + The "Safe RET" mitigation (see below) has been applied to protect the + kernel, but the IBPB-extending microcode has not been applied. User + space tasks may still be vulnerable. + + * 'Vulnerable: Microcode, no safe RET': Extended IBPB functionality microcode patch has been applied. It does not address User->Kernel and Guest->Host transitions protection but it @@ -72,11 +82,11 @@ The possible values in this file are: (spec_rstack_overflow=microcode) - * 'Mitigation: safe RET': + * 'Mitigation: Safe RET': - Software-only mitigation. It complements the extended IBPB microcode - patch functionality by addressing User->Kernel and Guest->Host - transitions protection. + Combined microcode/software mitigation. It complements the + extended IBPB microcode patch functionality by addressing + User->Kernel and Guest->Host transitions protection. Selected by default or by spec_rstack_overflow=safe-ret @@ -129,7 +139,7 @@ an indrect branch prediction barrier after having applied the required microcode patch for one's system. This mitigation comes also at a performance cost. -Mitigation: safe RET +Mitigation: Safe RET -------------------- The mitigation works by ensuring all RET instructions speculate to diff --git a/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst b/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst index 014167ef8dd1..444f84e22a91 100644 --- a/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst +++ b/Documentation/admin-guide/hw-vuln/tsx_async_abort.rst @@ -98,7 +98,19 @@ The possible values in this file are: * - 'Vulnerable' - The CPU is affected by this vulnerability and the microcode and kernel mitigation are not applied. * - 'Vulnerable: Clear CPU buffers attempted, no microcode' - - The system tries to clear the buffers but the microcode might not support the operation. + - The processor is vulnerable but microcode is not updated. The + mitigation is enabled on a best effort basis. + + If the processor is vulnerable but the availability of the microcode + based mitigation mechanism is not advertised via CPUID, the kernel + selects a best effort mitigation mode. This mode invokes the mitigation + instructions without a guarantee that they clear the CPU buffers. + + This is done to address virtualization scenarios where the host has the + microcode update applied, but the hypervisor is not yet updated to + expose the CPUID to the guest. If the host has updated microcode the + protection takes effect; otherwise a few CPU cycles are wasted + pointlessly. * - 'Mitigation: Clear CPU buffers' - The microcode has been updated to clear the buffers. TSX is still enabled. * - 'Mitigation: TSX disabled' @@ -106,25 +118,6 @@ The possible values in this file are: * - 'Not affected' - The CPU is not affected by this issue. -.. _ucode_needed: - -Best effort mitigation mode -^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -If the processor is vulnerable, but the availability of the microcode-based -mitigation mechanism is not advertised via CPUID the kernel selects a best -effort mitigation mode. This mode invokes the mitigation instructions -without a guarantee that they clear the CPU buffers. - -This is done to address virtualization scenarios where the host has the -microcode update applied, but the hypervisor is not yet updated to expose the -CPUID to the guest. If the host has updated microcode the protection takes -effect; otherwise a few CPU cycles are wasted pointlessly. - -The state in the tsx_async_abort sysfs file reflects this situation -accordingly. - - Mitigation mechanism -------------------- diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst index a748e7eb4429..5762e7477a0c 100644 --- a/Documentation/admin-guide/kdump/kdump.rst +++ b/Documentation/admin-guide/kdump/kdump.rst @@ -17,7 +17,7 @@ You can use common commands, such as cp, scp or makedumpfile to copy the memory image to a dump file on the local disk, or across the network to a remote system. -Kdump and kexec are currently supported on the x86, x86_64, ppc64, ia64, +Kdump and kexec are currently supported on the x86, x86_64, ppc64, s390x, arm and arm64 architectures. When the system kernel boots, it reserves a small section of memory for @@ -113,7 +113,7 @@ There are two possible methods of using Kdump. 2) Or use the system kernel binary itself as dump-capture kernel and there is no need to build a separate dump-capture kernel. This is possible only with the architectures which support a relocatable kernel. As - of today, i386, x86_64, ppc64, ia64, arm and arm64 architectures support + of today, i386, x86_64, ppc64, arm and arm64 architectures support relocatable kernel. Building a relocatable kernel is advantageous from the point of view that @@ -236,24 +236,6 @@ Dump-capture kernel config options (Arch Dependent, ppc64) Make and install the kernel and its modules. -Dump-capture kernel config options (Arch Dependent, ia64) ----------------------------------------------------------- - -- No specific options are required to create a dump-capture kernel - for ia64, other than those specified in the arch independent section - above. This means that it is possible to use the system kernel - as a dump-capture kernel if desired. - - The crashkernel region can be automatically placed by the system - kernel at runtime. This is done by specifying the base address as 0, - or omitting it all together:: - - crashkernel=256M@0 - - or:: - - crashkernel=256M - Dump-capture kernel config options (Arch Dependent, arm) ---------------------------------------------------------- @@ -348,11 +330,6 @@ Boot into System Kernel On ppc64, use "crashkernel=128M@32M". - On ia64, 256M@256M is a generous value that typically works. - The region may be automatically placed on ia64, see the - dump-capture kernel config option notes above. - If use sparse memory, the size should be rounded to GRANULE boundaries. - On s390x, typically use "crashkernel=xxM". The value of xx is dependent on the memory consumption of the kdump system. In general this is not dependent on the memory size of the production system. @@ -383,10 +360,6 @@ For ppc64: - Use vmlinux -For ia64: - - - Use vmlinux or vmlinuz.gz - For s390x: - Use image or bzImage @@ -428,14 +401,10 @@ to load dump-capture kernel:: --initrd=<initrd-for-dump-capture-kernel> \ --append="root=<root-dev> <arch-specific-options>" -Please note, that --args-linux does not need to be specified for ia64. -It is planned to make this a no-op on that architecture, but for now -it should be omitted - Following are the arch specific command line options to be used while loading dump-capture kernel. -For i386, x86_64 and ia64: +For i386 and x86_64: "1 irqpoll nr_cpus=1 reset_devices" diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 599e8d3bcbc3..78e4d2e7ba14 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -413,36 +413,6 @@ of a higher page table lookup overhead, and also consumes more page table space per process. Used to check whether PAE was enabled in the crash kernel when converting virtual addresses to physical addresses. -ia64 -==== - -pgdat_list|(pgdat_list, MAX_NUMNODES) -------------------------------------- - -pg_data_t array storing all NUMA nodes information. MAX_NUMNODES -indicates the number of the nodes. - -node_memblk|(node_memblk, NR_NODE_MEMBLKS) ------------------------------------------- - -List of node memory chunks. Filled when parsing the SRAT table to obtain -information about memory nodes. NR_NODE_MEMBLKS indicates the number of -node memory chunks. - -These values are used to compute the number of nodes the crashed kernel used. - -node_memblk_s|(node_memblk_s, start_paddr)|(node_memblk_s, size) ----------------------------------------------------------------- - -The size of a struct node_memblk_s and the offsets of the -node_memblk_s's members. Used to compute the number of nodes. - -PGTABLE_3|PGTABLE_4 -------------------- - -User-space tools need to know whether the crash kernel was in 3-level or -4-level paging mode. Used to distinguish the page table. - ARM64 ===== diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 0a1731a0f0ef..01c7082ee999 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -580,6 +580,10 @@ named mounts. Specifying both "all" and "named" disables all v1 hierarchies. + cgroup_favordynmods= [KNL] Enable or Disable favordynmods. + Format: { "true" | "false" } + Defaults to the value of CONFIG_CGROUP_FAVOR_DYNMODS. + cgroup.memory= [KNL] Pass options to the cgroup memory controller. Format: <string> nosocket -- Disable socket memory accounting. @@ -1331,6 +1335,7 @@ earlyprintk=dbgp[debugController#] earlyprintk=pciserial[,force],bus:device.function[,baudrate] earlyprintk=xdbc[xhciController#] + earlyprintk=bios earlyprintk is useful when the kernel crashes before the normal console is initialized. It is not enabled by @@ -1361,6 +1366,8 @@ The sclp output can only be used on s390. + The bios output can only be used on SuperH. + The optional "force" to "pciserial" enables use of a PCI device even when its classcode is not of the UART class. @@ -1449,7 +1456,7 @@ See comment before function elanfreq_setup() in arch/x86/kernel/cpu/cpufreq/elanfreq.c. - elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] + elfcorehdr=[size[KMG]@]offset[KMG] [PPC,SH,X86,S390] 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. @@ -1512,12 +1519,6 @@ floppy= [HW] See Documentation/admin-guide/blockdev/floppy.rst. - force_pal_cache_flush - [IA-64] Avoid check_sal_cache_flush which may hang on - buggy SAL_CACHE_FLUSH implementations. Using this - parameter will force ia64_sal_cache_flush to call - ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. - forcepae [X86-32] Forcefully enable Physical Address Extension (PAE). Many Pentium M systems disable PAE but may have a @@ -1893,6 +1894,12 @@ 0 -- machine default 1 -- force brightness inversion + ia32_emulation= [X86-64] + Format: <bool> + When true, allows loading 32-bit programs and executing 32-bit + 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>]]] @@ -2913,6 +2920,38 @@ to extract confidential information from the kernel are also disabled. + locktorture.acq_writer_lim= [KNL] + Set the time limit in jiffies for a lock + acquisition. Acquisitions exceeding this limit + will result in a splat once they do complete. + + locktorture.bind_readers= [KNL] + Specify the list of CPUs to which the readers are + to be bound. + + locktorture.bind_writers= [KNL] + Specify the list of CPUs to which the writers are + to be bound. + + locktorture.call_rcu_chains= [KNL] + Specify the number of self-propagating call_rcu() + chains to set up. These are used to ensure that + there is a high probability of an RCU grace period + in progress at any given time. Defaults to 0, + which disables these call_rcu() chains. + + locktorture.long_hold= [KNL] + Specify the duration in milliseconds for the + occasional long-duration lock hold time. Defaults + to 100 milliseconds. Select 0 to disable. + + locktorture.nested_locks= [KNL] + Specify the maximum lock nesting depth that + locktorture is to exercise, up to a limit of 8 + (MAX_NESTED_LOCKS). Specify zero to disable. + Note that this parameter is ineffective on types + of locks that do not support nested acquisition. + locktorture.nreaders_stress= [KNL] Set the number of locking read-acquisition kthreads. Defaults to being automatically set based on the @@ -2928,6 +2967,25 @@ Set time (s) between CPU-hotplug operations, or zero to disable CPU-hotplug testing. + locktorture.rt_boost= [KNL] + Do periodic testing of real-time lock priority + boosting. Select 0 to disable, 1 to boost + only rt_mutex, and 2 to boost unconditionally. + Defaults to 2, which might seem to be an + odd choice, but which should be harmless for + non-real-time spinlocks, due to their disabling + of preemption. Note that non-realtime mutexes + disable boosting. + + locktorture.rt_boost_factor= [KNL] + Number that determines how often and for how + long priority boosting is exercised. This is + scaled down by the number of writers, so that the + number of boosts per unit time remains roughly + constant as the number of writers increases. + On the other hand, the duration of each boost + increases with the number of writers. + locktorture.shuffle_interval= [KNL] Set task-shuffle interval (jiffies). Shuffling tasks allows some CPUs to go into dyntick-idle @@ -2950,13 +3008,13 @@ locktorture.torture_type= [KNL] Specify the locking implementation to test. + locktorture.verbose= [KNL] + Enable additional printk() statements. + locktorture.writer_fifo= [KNL] Run the write-side locktorture kthreads at sched_set_fifo() real-time priority. - locktorture.verbose= [KNL] - Enable additional printk() statements. - logibm.irq= [HW,MOUSE] Logitech Bus Mouse Driver Format: <irq> @@ -4769,6 +4827,13 @@ Set maximum number of finished RCU callbacks to process in one batch. + rcutree.do_rcu_barrier= [KNL] + Request a call to rcu_barrier(). This is + throttled so that userspace tests can safely + hammer on the sysfs variable if they so choose. + If triggered before the RCU grace-period machinery + is fully active, this will error out with EAGAIN. + rcutree.dump_tree= [KNL] Dump the structure of the rcu_node combining tree out at early boot. This is used for diagnostic @@ -5422,6 +5487,12 @@ test until boot completes in order to avoid interference. + refscale.lookup_instances= [KNL] + Number of data elements to use for the forms of + SLAB_TYPESAFE_BY_RCU testing. A negative number + is negated and multiplied by nr_cpu_ids, while + zero specifies nr_cpu_ids. + refscale.loops= [KNL] Set the number of loops over the synchronization primitive under test. Increasing this number @@ -5858,6 +5929,13 @@ This feature may be more efficiently disabled using the csdlock_debug- kernel parameter. + smp.panic_on_ipistall= [KNL] + If a csd_lock_timeout extends for more than + the specified number of milliseconds, panic the + system. By default, let CSD-lock acquisition + 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 diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index e27a1c3f634e..98d304010170 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -53,6 +53,7 @@ detailed description): - Lap mode sensor - Setting keyboard language - WWAN Antenna type + - Auxmac A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure @@ -1511,6 +1512,25 @@ Currently 2 antenna types are supported as mentioned below: The property is read-only. If the platform doesn't have support the sysfs class is not created. +Auxmac +------ + +sysfs: auxmac + +Some newer Thinkpads have a feature called MAC Address Pass-through. This +feature is implemented by the system firmware to provide a system unique MAC, +that can override a dock or USB ethernet dongle MAC, when connected to a +network. This property enables user-space to easily determine the MAC address +if the feature is enabled. + +The values of this auxiliary MAC are: + + cat /sys/devices/platform/thinkpad_acpi/auxmac + +If the feature is disabled, the value will be 'disabled'. + +This property is read-only. + Adaptive keyboard ----------------- diff --git a/Documentation/admin-guide/mm/memory-hotplug.rst b/Documentation/admin-guide/mm/memory-hotplug.rst index cfe034cf1e87..098f14d83e99 100644 --- a/Documentation/admin-guide/mm/memory-hotplug.rst +++ b/Documentation/admin-guide/mm/memory-hotplug.rst @@ -33,7 +33,7 @@ used to expose persistent memory, other performance-differentiated memory and reserved memory regions as ordinary system RAM to Linux. Linux only supports memory hot(un)plug on selected 64 bit architectures, such as -x86_64, arm64, ppc64, s390x and ia64. +x86_64, arm64, ppc64 and s390x. Memory Hot(Un)Plug Granularity ------------------------------ @@ -75,7 +75,7 @@ Memory hotunplug consists of two phases: (1) Offlining memory blocks (2) Removing the memory from Linux -In the fist phase, memory is "hidden" from the page allocator again, for +In the first phase, memory is "hidden" from the page allocator again, for example, by migrating busy memory to other memory locations and removing all relevant free pages from the page allocator After this phase, the memory is no longer visible in memory statistics of the system. @@ -250,15 +250,15 @@ Observing the State of Memory Blocks The state (online/offline/going-offline) of a memory block can be observed either via:: - % cat /sys/device/system/memory/memoryXXX/state + % cat /sys/devices/system/memory/memoryXXX/state Or alternatively (1/0) via:: - % cat /sys/device/system/memory/memoryXXX/online + % cat /sys/devices/system/memory/memoryXXX/online For an online memory block, the managing zone can be observed via:: - % cat /sys/device/system/memory/memoryXXX/valid_zones + % cat /sys/devices/system/memory/memoryXXX/valid_zones Configuring Memory Hot(Un)Plug ============================== @@ -326,7 +326,7 @@ however, a memory block might span memory holes. A memory block spanning memory holes cannot be offlined. For example, assume 1 GiB memory block size. A device for a memory starting at -0x100000000 is ``/sys/device/system/memory/memory4``:: +0x100000000 is ``/sys/devices/system/memory/memory4``:: (0x100000000 / 1Gib = 4) diff --git a/Documentation/admin-guide/perf/ampere_cspmu.rst b/Documentation/admin-guide/perf/ampere_cspmu.rst new file mode 100644 index 000000000000..94f93f5aee6c --- /dev/null +++ b/Documentation/admin-guide/perf/ampere_cspmu.rst @@ -0,0 +1,29 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================================ +Ampere SoC Performance Monitoring Unit (PMU) +============================================ + +Ampere SoC PMU is a generic PMU IP that follows Arm CoreSight PMU architecture. +Therefore, the driver is implemented as a submodule of arm_cspmu driver. At the +first phase it's used for counting MCU events on AmpereOne. + + +MCU PMU events +-------------- + +The PMU driver supports setting filters for "rank", "bank", and "threshold". +Note, that the filters are per PMU instance rather than per event. + + +Example for perf tool use:: + + / # perf list ampere + + ampere_mcu_pmu_0/act_sent/ [Kernel PMU event] + <...> + ampere_mcu_pmu_1/rd_sent/ [Kernel PMU event] + <...> + + / # perf stat -a -e ampere_mcu_pmu_0/act_sent,bank=5,rank=3,threshold=2/,ampere_mcu_pmu_1/rd_sent/ \ + sleep 1 diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst index f60be04e4e33..a2e6f2c81146 100644 --- a/Documentation/admin-guide/perf/index.rst +++ b/Documentation/admin-guide/perf/index.rst @@ -22,3 +22,4 @@ Performance monitor support nvidia-pmu meson-ddr-pmu cxl + ampere_cspmu diff --git a/Documentation/admin-guide/pm/intel_idle.rst b/Documentation/admin-guide/pm/intel_idle.rst index b799a43da62e..39bd6ecce7de 100644 --- a/Documentation/admin-guide/pm/intel_idle.rst +++ b/Documentation/admin-guide/pm/intel_idle.rst @@ -170,7 +170,7 @@ and ``idle=nomwait``. If any of them is present in the kernel command line, the ``MWAIT`` instruction is not allowed to be used, so the initialization of ``intel_idle`` will fail. -Apart from that there are four module parameters recognized by ``intel_idle`` +Apart from that there are five module parameters recognized by ``intel_idle`` itself that can be set via the kernel command line (they cannot be updated via sysfs, so that is the only way to change their values). @@ -216,6 +216,21 @@ are ignored). The idle states disabled this way can be enabled (on a per-CPU basis) from user space via ``sysfs``. +The ``ibrs_off`` module parameter is a boolean flag (defaults to +false). If set, it is used to control if IBRS (Indirect Branch Restricted +Speculation) should be turned off when the CPU enters an idle state. +This flag does not affect CPUs that use Enhanced IBRS which can remain +on with little performance impact. + +For some CPUs, IBRS will be selected as mitigation for Spectre v2 and Retbleed +security vulnerabilities by default. Leaving the IBRS mode on while idling may +have a performance impact on its sibling CPU. The IBRS mode will be turned off +by default when the CPU enters into a deep idle state, but not in some +shallower ones. Setting the ``ibrs_off`` module parameter will force the IBRS +mode to off when the CPU is in any one of the available idle states. This may +help performance of a sibling CPU at the expense of a slightly higher wakeup +latency for the idle CPU. + .. _intel-idle-core-and-package-idle-states: diff --git a/Documentation/admin-guide/pstore-blk.rst b/Documentation/admin-guide/pstore-blk.rst index 2d22ead9520e..1bb2a1c292aa 100644 --- a/Documentation/admin-guide/pstore-blk.rst +++ b/Documentation/admin-guide/pstore-blk.rst @@ -76,7 +76,7 @@ kmsg_size ~~~~~~~~~ The chunk size in KB for oops/panic front-end. It **MUST** be a multiple of 4. -It's optional if you do not care oops/panic log. +It's optional if you do not care about the oops/panic log. There are multiple chunks for oops/panic front-end depending on the remaining space except other pstore front-ends. @@ -88,7 +88,7 @@ pmsg_size ~~~~~~~~~ The chunk size in KB for pmsg front-end. It **MUST** be a multiple of 4. -It's optional if you do not care pmsg log. +It's optional if you do not care about the pmsg log. Unlike oops/panic front-end, there is only one chunk for pmsg front-end. @@ -100,7 +100,7 @@ console_size ~~~~~~~~~~~~ The chunk size in KB for console front-end. It **MUST** be a multiple of 4. -It's optional if you do not care console log. +It's optional if you do not care about the console log. Similar to pmsg front-end, there is only one chunk for console front-end. @@ -111,7 +111,7 @@ ftrace_size ~~~~~~~~~~~ The chunk size in KB for ftrace front-end. It **MUST** be a multiple of 4. -It's optional if you do not care console log. +It's optional if you do not care about the ftrace log. Similar to oops front-end, there are multiple chunks for ftrace front-end depending on the count of cpu processors. Each chunk size is equal to diff --git a/Documentation/admin-guide/spkguide.txt b/Documentation/admin-guide/spkguide.txt index 74ea7f391942..0d5965138f8f 100644 --- a/Documentation/admin-guide/spkguide.txt +++ b/Documentation/admin-guide/spkguide.txt @@ -7,7 +7,7 @@ Last modified on Mon Sep 27 14:26:31 2010 Document version 1.3 Copyright (c) 2005 Gene Collins -Copyright (c) 2008 Samuel Thibault +Copyright (c) 2008, 2023 Samuel Thibault Copyright (c) 2009, 2010 the Speakup Team Permission is granted to copy, distribute and/or modify this document @@ -83,8 +83,7 @@ spkout -- Speak Out txprt -- Transport dummy -- Plain text terminal -Note: Speakup does * NOT * support usb connections! Speakup also does * -NOT * support the internal Tripletalk! +Note: Speakup does * NOT * support the internal Tripletalk! Speakup does support two other synthesizers, but because they work in conjunction with other software, they must be loaded as modules after @@ -94,6 +93,12 @@ These are as follows: decpc -- DecTalk PC (not available at boot up) soft -- One of several software synthesizers (not available at boot up) +By default speakup looks for the synthesizer on the ttyS0 serial port. This can +be changed with the device parameter of the modules, for instance for +DoubleTalk LT: + +speakup_ltlk.dev=ttyUSB0 + See the sections on loading modules and software synthesizers later in this manual for further details. It should be noted here that the speakup.synth boot parameter will have no effect if Speakup has been diff --git a/Documentation/admin-guide/sysctl/fs.rst b/Documentation/admin-guide/sysctl/fs.rst index a321b84eccaa..47499a1742bd 100644 --- a/Documentation/admin-guide/sysctl/fs.rst +++ b/Documentation/admin-guide/sysctl/fs.rst @@ -42,16 +42,16 @@ pre-allocation or re-sizing of any kernel data structures. dentry-state ------------ -This file shows the values in ``struct dentry_stat``, as defined in -``linux/include/linux/dcache.h``:: +This file shows the values in ``struct dentry_stat_t``, as defined in +``fs/dcache.c``:: struct dentry_stat_t dentry_stat { - int nr_dentry; - int nr_unused; - int age_limit; /* age in seconds */ - int want_pages; /* pages requested by system */ - int nr_negative; /* # of unused negative dentries */ - int dummy; /* Reserved for future use */ + long nr_dentry; + long nr_unused; + long age_limit; /* age in seconds */ + long want_pages; /* pages requested by system */ + long nr_negative; /* # of unused negative dentries */ + long dummy; /* Reserved for future use */ }; Dentries are dynamically allocated and deallocated. diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index cf33de56da27..6584a1f9bfe3 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -436,7 +436,7 @@ ignore-unaligned-usertrap On architectures where unaligned accesses cause traps, and where this feature is supported (``CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN``; -currently, ``arc``, ``ia64`` and ``loongarch``), controls whether all +currently, ``arc`` and ``loongarch``), controls whether all unaligned traps are logged. = ============================================================= @@ -445,10 +445,7 @@ unaligned traps are logged. setting. = ============================================================= -See also `unaligned-trap`_ and `unaligned-dump-stack`_. On ``ia64``, -this allows system administrators to override the -``IA64_THREAD_UAC_NOPRINT`` ``prctl`` and avoid logs being flooded. - +See also `unaligned-trap`_. io_uring_disabled ================= @@ -1182,7 +1179,8 @@ automatically on platforms where it can run (that is, platforms with asymmetric CPU topologies and having an Energy Model available). If your platform happens to meet the requirements for EAS but you do not want to use it, change -this value to 0. +this value to 0. On Non-EAS platforms, write operation fails and +read doesn't return anything. task_delayacct =============== @@ -1538,22 +1536,6 @@ See Documentation/admin-guide/kernel-parameters.rst and Documentation/trace/boottime-trace.rst. -.. _unaligned-dump-stack: - -unaligned-dump-stack (ia64) -=========================== - -When logging unaligned accesses, controls whether the stack is -dumped. - -= =================================================== -0 Do not dump the stack. This is the default setting. -1 Dump the stack. -= =================================================== - -See also `ignore-unaligned-usertrap`_. - - unaligned-trap ============== diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index 4877563241f3..c7525942f12c 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -71,6 +71,7 @@ two flavors of JITs, the newer eBPF JIT currently supported on: - s390x - riscv64 - riscv32 + - loongarch64 And the older cBPF JIT supported on the following archs: diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index 45ba1f4dc004..c59889de122b 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -742,8 +742,8 @@ overcommit_memory This value contains a flag that enables memory overcommitment. -When this flag is 0, the kernel attempts to estimate the amount -of free memory left when userspace requests more memory. +When this flag is 0, the kernel compares the userspace memory request +size against total memory plus swap and rejects obvious overcommits. When this flag is 1, the kernel pretends there is always enough memory until it actually runs out. |