diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/memory.rst | 7 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 130 | ||||
| -rw-r--r-- | Documentation/admin-guide/hw-vuln/srso.rst | 24 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 87 | ||||
| -rw-r--r-- | Documentation/admin-guide/laptops/thinkpad-acpi.rst | 20 | ||||
| -rw-r--r-- | Documentation/admin-guide/perf/ampere_cspmu.rst | 29 | ||||
| -rw-r--r-- | Documentation/admin-guide/perf/index.rst | 1 | ||||
| -rw-r--r-- | Documentation/admin-guide/pm/intel_idle.rst | 17 | ||||
| -rw-r--r-- | Documentation/admin-guide/pstore-blk.rst | 8 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/kernel.rst | 3 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/net.rst | 1 |
11 files changed, 279 insertions, 48 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..e440aee4fe94 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 -------------------------- @@ -2226,6 +2233,49 @@ 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 +2289,41 @@ 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 +2346,33 @@ 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 +2382,11 @@ 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/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/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 229db97b1b48..07625c60aa8a 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. @@ -1887,6 +1891,12 @@ 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>]]] @@ -2907,6 +2917,38 @@ 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 @@ -2922,6 +2964,25 @@ 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 @@ -2944,13 +3005,13 @@ 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> @@ -4763,6 +4824,13 @@ 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 @@ -5416,6 +5484,12 @@ 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 @@ -5852,6 +5926,13 @@ 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/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/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 8eefa807d8e6..6584a1f9bfe3 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -1179,7 +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 =============== 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: |