diff options
Diffstat (limited to 'Documentation/admin-guide')
26 files changed, 171 insertions, 186 deletions
diff --git a/Documentation/admin-guide/README.rst b/Documentation/admin-guide/README.rst index eb9452668909..70b02f30013a 100644 --- a/Documentation/admin-guide/README.rst +++ b/Documentation/admin-guide/README.rst @@ -165,7 +165,7 @@ Configuring the kernel "make xconfig" Qt based configuration tool. - "make gconfig" GTK+ based configuration tool. + "make gconfig" GTK based configuration tool. "make oldconfig" Default all questions based on the contents of your existing ./.config file and asking about @@ -176,7 +176,7 @@ Configuring the kernel values without prompting. "make defconfig" Create a ./.config file by using the default - symbol values from either arch/$ARCH/defconfig + symbol values from either arch/$ARCH/configs/defconfig or arch/$ARCH/configs/${PLATFORM}_defconfig, depending on the architecture. diff --git a/Documentation/admin-guide/abi-obsolete-files.rst b/Documentation/admin-guide/abi-obsolete-files.rst new file mode 100644 index 000000000000..3061a916b4b5 --- /dev/null +++ b/Documentation/admin-guide/abi-obsolete-files.rst @@ -0,0 +1,7 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Obsolete ABI Files +================== + +.. kernel-abi:: obsolete + :no-symbols: diff --git a/Documentation/admin-guide/abi-obsolete.rst b/Documentation/admin-guide/abi-obsolete.rst index 594e697aa1b2..640f3903e847 100644 --- a/Documentation/admin-guide/abi-obsolete.rst +++ b/Documentation/admin-guide/abi-obsolete.rst @@ -1,3 +1,5 @@ +.. SPDX-License-Identifier: GPL-2.0 + ABI obsolete symbols ==================== @@ -7,5 +9,5 @@ marked to be removed at some later point in time. The description of the interface will document the reason why it is obsolete and when it can be expected to be removed. -.. kernel-abi:: ABI/obsolete - :rst: +.. kernel-abi:: obsolete + :no-files: diff --git a/Documentation/admin-guide/abi-removed-files.rst b/Documentation/admin-guide/abi-removed-files.rst new file mode 100644 index 000000000000..f1bdfadd2ec4 --- /dev/null +++ b/Documentation/admin-guide/abi-removed-files.rst @@ -0,0 +1,7 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Removed ABI Files +================= + +.. kernel-abi:: removed + :no-symbols: diff --git a/Documentation/admin-guide/abi-removed.rst b/Documentation/admin-guide/abi-removed.rst index f9e000c81828..88832d3eacd6 100644 --- a/Documentation/admin-guide/abi-removed.rst +++ b/Documentation/admin-guide/abi-removed.rst @@ -1,5 +1,7 @@ +.. SPDX-License-Identifier: GPL-2.0 + ABI removed symbols =================== -.. kernel-abi:: ABI/removed - :rst: +.. kernel-abi:: removed + :no-files: diff --git a/Documentation/admin-guide/abi-stable-files.rst b/Documentation/admin-guide/abi-stable-files.rst new file mode 100644 index 000000000000..f867738fc178 --- /dev/null +++ b/Documentation/admin-guide/abi-stable-files.rst @@ -0,0 +1,7 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Stable ABI Files +================ + +.. kernel-abi:: stable + :no-symbols: diff --git a/Documentation/admin-guide/abi-stable.rst b/Documentation/admin-guide/abi-stable.rst index fc3361d847b1..528c68401f4b 100644 --- a/Documentation/admin-guide/abi-stable.rst +++ b/Documentation/admin-guide/abi-stable.rst @@ -1,3 +1,5 @@ +.. SPDX-License-Identifier: GPL-2.0 + ABI stable symbols ================== @@ -10,5 +12,5 @@ for at least 2 years. Most interfaces (like syscalls) are expected to never change and always be available. -.. kernel-abi:: ABI/stable - :rst: +.. kernel-abi:: stable + :no-files: diff --git a/Documentation/admin-guide/abi-testing-files.rst b/Documentation/admin-guide/abi-testing-files.rst new file mode 100644 index 000000000000..1da868e42fdb --- /dev/null +++ b/Documentation/admin-guide/abi-testing-files.rst @@ -0,0 +1,7 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Testing ABI Files +================= + +.. kernel-abi:: testing + :no-symbols: diff --git a/Documentation/admin-guide/abi-testing.rst b/Documentation/admin-guide/abi-testing.rst index 19767926b344..6153ebd38e2d 100644 --- a/Documentation/admin-guide/abi-testing.rst +++ b/Documentation/admin-guide/abi-testing.rst @@ -1,3 +1,5 @@ +.. SPDX-License-Identifier: GPL-2.0 + ABI testing symbols =================== @@ -16,5 +18,5 @@ Programs that use these interfaces are strongly encouraged to add their name to the description of these interfaces, so that the kernel developers can easily notify them if any changes occur. -.. kernel-abi:: ABI/testing - :rst: +.. kernel-abi:: testing + :no-files: diff --git a/Documentation/admin-guide/abi.rst b/Documentation/admin-guide/abi.rst index bcab3ef2597c..c6039359e585 100644 --- a/Documentation/admin-guide/abi.rst +++ b/Documentation/admin-guide/abi.rst @@ -1,7 +1,14 @@ +.. SPDX-License-Identifier: GPL-2.0 + ===================== Linux ABI description ===================== +.. kernel-abi:: README + +ABI symbols +----------- + .. toctree:: :maxdepth: 2 @@ -9,3 +16,14 @@ Linux ABI description abi-testing abi-obsolete abi-removed + +ABI files +--------- + +.. toctree:: + :maxdepth: 2 + + abi-stable-files + abi-testing-files + abi-obsolete-files + abi-removed-files diff --git a/Documentation/admin-guide/cgroup-v1/freezer-subsystem.rst b/Documentation/admin-guide/cgroup-v1/freezer-subsystem.rst index 582d3427de3f..a964aff373b1 100644 --- a/Documentation/admin-guide/cgroup-v1/freezer-subsystem.rst +++ b/Documentation/admin-guide/cgroup-v1/freezer-subsystem.rst @@ -125,3 +125,7 @@ to unfreeze all tasks in the container:: This is the basic mechanism which should do the right thing for user space task in a simple scenario. + +This freezer implementation is affected by shortcomings (see commit +76f969e8948d8 ("cgroup: cgroup v2 freezer")) and cgroup v2 freezer is +recommended. diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index 286d16fc22eb..02b8206a3594 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -90,6 +90,7 @@ Brief summary of control files. used. memory.swappiness set/show swappiness parameter of vmscan (See sysctl's vm.swappiness) + Per memcg knob does not exist in cgroup v2. memory.move_charge_at_immigrate This knob is deprecated. memory.oom_control set/show oom controls. This knob is deprecated and shouldn't be diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index cb1b4e759b7e..f293a13b42ed 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1076,15 +1076,20 @@ cpufreq governor about the minimum desired frequency which should always be provided by a CPU, as well as the maximum desired frequency, which should not be exceeded by a CPU. -WARNING: cgroup2 doesn't yet support control of realtime processes. For -a kernel built with the CONFIG_RT_GROUP_SCHED option enabled for group -scheduling of realtime processes, the cpu controller can only be enabled -when all RT processes are in the root cgroup. This limitation does -not apply if CONFIG_RT_GROUP_SCHED is disabled. Be aware that system -management software may already have placed RT processes into nonroot -cgroups during the system boot process, and these processes may need -to be moved to the root cgroup before the cpu controller can be enabled -with a CONFIG_RT_GROUP_SCHED enabled kernel. +WARNING: cgroup2 cpu controller doesn't yet fully support the control of +realtime processes. For a kernel built with the CONFIG_RT_GROUP_SCHED option +enabled for group scheduling of realtime processes, the cpu controller can only +be enabled when all RT processes are in the root cgroup. Be aware that system +management software may already have placed RT processes into non-root cgroups +during the system boot process, and these processes may need to be moved to the +root cgroup before the cpu controller can be enabled with a +CONFIG_RT_GROUP_SCHED enabled kernel. + +With CONFIG_RT_GROUP_SCHED disabled, this limitation does not apply and some of +the interface files either affect realtime processes or account for them. See +the following section for details. Only the cpu controller is affected by +CONFIG_RT_GROUP_SCHED. Other controllers can be used for the resource control of +realtime processes irrespective of CONFIG_RT_GROUP_SCHED. CPU Interface Files diff --git a/Documentation/admin-guide/gpio/gpio-sim.rst b/Documentation/admin-guide/gpio/gpio-sim.rst index 1cc5567a4bbe..35d49ccd49e0 100644 --- a/Documentation/admin-guide/gpio/gpio-sim.rst +++ b/Documentation/admin-guide/gpio/gpio-sim.rst @@ -71,7 +71,7 @@ specific lines. The name of those subdirectories must take the form of: ``'line<offset>'`` (e.g. ``'line0'``, ``'line20'``, etc.) as the name will be used by the module to assign the config to the specific line at given offset. -Once the confiuration is complete, the ``'live'`` attribute must be set to 1 in +Once the configuration is complete, the ``'live'`` attribute must be set to 1 in order to instantiate the chip. It can be set back to 0 to destroy the simulated chip. The module will synchronously wait for the new simulated device to be successfully probed and if this doesn't happen, writing to ``'live'`` will diff --git a/Documentation/admin-guide/gpio/gpio-virtuser.rst b/Documentation/admin-guide/gpio/gpio-virtuser.rst index 2aca70db9f3b..7e7c0df51640 100644 --- a/Documentation/admin-guide/gpio/gpio-virtuser.rst +++ b/Documentation/admin-guide/gpio/gpio-virtuser.rst @@ -92,7 +92,7 @@ struct. The first two take string values as arguments: Activating GPIO consumers ------------------------- -Once the confiuration is complete, the ``'live'`` attribute must be set to 1 in +Once the configuration is complete, the ``'live'`` attribute must be set to 1 in order to instantiate the consumer. It can be set back to 0 to destroy the virtual device. The module will synchronously wait for the new simulated device to be successfully probed and if this doesn't happen, writing to ``'live'`` will diff --git a/Documentation/admin-guide/highuid.rst b/Documentation/admin-guide/highuid.rst deleted file mode 100644 index 6ee70465c0ea..000000000000 --- a/Documentation/admin-guide/highuid.rst +++ /dev/null @@ -1,80 +0,0 @@ -=================================================== -Notes on the change from 16-bit UIDs to 32-bit UIDs -=================================================== - -:Author: Chris Wing <wingc@umich.edu> -:Last updated: January 11, 2000 - -- kernel code MUST take into account __kernel_uid_t and __kernel_uid32_t - when communicating between user and kernel space in an ioctl or data - structure. - -- kernel code should use uid_t and gid_t in kernel-private structures and - code. - -What's left to be done for 32-bit UIDs on all Linux architectures: - -- Disk quotas have an interesting limitation that is not related to the - maximum UID/GID. They are limited by the maximum file size on the - underlying filesystem, because quota records are written at offsets - corresponding to the UID in question. - Further investigation is needed to see if the quota system can cope - properly with huge UIDs. If it can deal with 64-bit file offsets on all - architectures, this should not be a problem. - -- Decide whether or not to keep backwards compatibility with the system - accounting file, or if we should break it as the comments suggest - (currently, the old 16-bit UID and GID are still written to disk, and - part of the former pad space is used to store separate 32-bit UID and - GID) - -- Need to validate that OS emulation calls the 16-bit UID - compatibility syscalls, if the OS being emulated used 16-bit UIDs, or - uses the 32-bit UID system calls properly otherwise. - - This affects at least: - - - iBCS on Intel - - - sparc32 emulation on sparc64 - (need to support whatever new 32-bit UID system calls are added to - sparc32) - -- Validate that all filesystems behave properly. - - At present, 32-bit UIDs _should_ work for: - - - ext2 - - ufs - - isofs - - nfs - - coda - - udf - - Ioctl() fixups have been made for: - - - ncpfs - - smbfs - - Filesystems with simple fixups to prevent 16-bit UID wraparound: - - - minix - - sysv - - qnx4 - - Other filesystems have not been checked yet. - -- The ncpfs and smpfs filesystems cannot presently use 32-bit UIDs in - all ioctl()s. Some new ioctl()s have been added with 32-bit UIDs, but - more are needed. (as well as new user<->kernel data structures) - -- The ELF core dump format only supports 16-bit UIDs on arm, i386, m68k, - sh, and sparc32. Fixing this is probably not that important, but would - require adding a new ELF section. - -- The ioctl()s used to control the in-kernel NFS server only support - 16-bit UIDs on arm, i386, m68k, sh, and sparc32. - -- make sure that the UID mapping feature of AX25 networking works properly - (it should be safe because it's always used a 32-bit integer to - communicate between user and kernel) diff --git a/Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst b/Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst index 0585d02b9a6c..ad15417d39f9 100644 --- a/Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst +++ b/Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst @@ -29,14 +29,6 @@ Below is the list of affected Intel processors [#f1]_: RAPTORLAKE_S 06_BFH =================== ============ -As an exception to this table, Intel Xeon E family parts ALDERLAKE(06_97H) and -RAPTORLAKE(06_B7H) codenamed Catlow are not affected. They are reported as -vulnerable in Linux because they share the same family/model with an affected -part. Unlike their affected counterparts, they do not enumerate RFDS_CLEAR or -CPUID.HYBRID. This information could be used to distinguish between the -affected and unaffected parts, but it is deemed not worth adding complexity as -the reporting is fixed automatically when these parts enumerate RFDS_NO. - Mitigation ========== Intel released a microcode update that enables software to clear sensitive diff --git a/Documentation/admin-guide/hw-vuln/srso.rst b/Documentation/admin-guide/hw-vuln/srso.rst index 2ad1c05b8c88..66af95251a3d 100644 --- a/Documentation/admin-guide/hw-vuln/srso.rst +++ b/Documentation/admin-guide/hw-vuln/srso.rst @@ -104,7 +104,20 @@ The possible values in this file are: (spec_rstack_overflow=ibpb-vmexit) + * 'Mitigation: Reduced Speculation': + This mitigation gets automatically enabled when the above one "IBPB on + VMEXIT" has been selected and the CPU supports the BpSpecReduce bit. + + It gets automatically enabled on machines which have the + SRSO_USER_KERNEL_NO=1 CPUID bit. In that case, the code logic is to switch + to the above =ibpb-vmexit mitigation because the user/kernel boundary is + not affected anymore and thus "safe RET" is not needed. + + After enabling the IBPB on VMEXIT mitigation option, the BpSpecReduce bit + is detected (functionality present on all such machines) and that + practically overrides IBPB on VMEXIT as it has a lot less performance + impact and takes care of the guest->host attack vector too. In order to exploit vulnerability, an attacker needs to: diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst index c8af32a8f800..259d79fbeb94 100644 --- a/Documentation/admin-guide/index.rst +++ b/Documentation/admin-guide/index.rst @@ -187,7 +187,6 @@ A few hard-to-categorize and generally obsolete documents. .. toctree:: :maxdepth: 1 - highuid ldm unicode diff --git a/Documentation/admin-guide/iostats.rst b/Documentation/admin-guide/iostats.rst index 609a3201fd4e..9453196ade51 100644 --- a/Documentation/admin-guide/iostats.rst +++ b/Documentation/admin-guide/iostats.rst @@ -2,62 +2,39 @@ I/O statistics fields ===================== -Since 2.4.20 (and some versions before, with patches), and 2.5.45, -more extensive disk statistics have been introduced to help measure disk -activity. Tools such as ``sar`` and ``iostat`` typically interpret these and do -the work for you, but in case you are interested in creating your own -tools, the fields are explained here. - -In 2.4 now, the information is found as additional fields in -``/proc/partitions``. In 2.6 and upper, the same information is found in two -places: one is in the file ``/proc/diskstats``, and the other is within -the sysfs file system, which must be mounted in order to obtain -the information. Throughout this document we'll assume that sysfs -is mounted on ``/sys``, although of course it may be mounted anywhere. -Both ``/proc/diskstats`` and sysfs use the same source for the information -and so should not differ. - -Here are examples of these different formats:: - - 2.4: - 3 0 39082680 hda 446216 784926 9550688 4382310 424847 312726 5922052 19310380 0 3376340 23705160 - 3 1 9221278 hda1 35486 0 35496 38030 0 0 0 0 0 38030 38030 - - 2.6+ sysfs: - 446216 784926 9550688 4382310 424847 312726 5922052 19310380 0 3376340 23705160 - 35486 38030 38030 38030 - - 2.6+ diskstats: - 3 0 hda 446216 784926 9550688 4382310 424847 312726 5922052 19310380 0 3376340 23705160 - 3 1 hda1 35486 38030 38030 38030 - - 4.18+ diskstats: - 3 0 hda 446216 784926 9550688 4382310 424847 312726 5922052 19310380 0 3376340 23705160 0 0 0 0 - -On 2.4 you might execute ``grep 'hda ' /proc/partitions``. On 2.6+, you have -a choice of ``cat /sys/block/hda/stat`` or ``grep 'hda ' /proc/diskstats``. - -The advantage of one over the other is that the sysfs choice works well -if you are watching a known, small set of disks. ``/proc/diskstats`` may -be a better choice if you are watching a large number of disks because -you'll avoid the overhead of 50, 100, or 500 or more opens/closes with -each snapshot of your disk statistics. - -In 2.4, the statistics fields are those after the device name. In -the above example, the first field of statistics would be 446216. -By contrast, in 2.6+ if you look at ``/sys/block/hda/stat``, you'll -find just the 15 fields, beginning with 446216. If you look at -``/proc/diskstats``, the 15 fields will be preceded by the major and -minor device numbers, and device name. Each of these formats provides -15 fields of statistics, each meaning exactly the same things. -All fields except field 9 are cumulative since boot. Field 9 should -go to zero as I/Os complete; all others only increase (unless they -overflow and wrap). Wrapping might eventually occur on a very busy -or long-lived system; so applications should be prepared to deal with -it. Regarding wrapping, the types of the fields are either unsigned -int (32 bit) or unsigned long (32-bit or 64-bit, depending on your -machine) as noted per-field below. Unless your observations are very -spread in time, these fields should not wrap twice before you notice it. +The kernel exposes disk statistics via ``/proc/diskstats`` and +``/sys/block/<device>/stat``. These stats are usually accessed via tools +such as ``sar`` and ``iostat``. + +Here are examples using a disk with two partitions:: + + /proc/diskstats: + 259 0 nvme0n1 255999 814 12369153 47919 996852 81 36123024 425995 0 301795 580470 0 0 0 0 60602 106555 + 259 1 nvme0n1p1 492 813 17572 96 848 81 108288 210 0 76 307 0 0 0 0 0 0 + 259 2 nvme0n1p2 255401 1 12343477 47799 996004 0 36014736 425784 0 344336 473584 0 0 0 0 0 0 + + /sys/block/nvme0n1/stat: + 255999 814 12369153 47919 996858 81 36123056 426009 0 301809 580491 0 0 0 0 60605 106562 + + /sys/block/nvme0n1/nvme0n1p1/stat: + 492 813 17572 96 848 81 108288 210 0 76 307 0 0 0 0 0 0 + +Both files contain the same 17 statistics. ``/sys/block/<device>/stat`` +contains the fields for ``<device>``. In ``/proc/diskstats`` the fields +are prefixed with the major and minor device numbers and the device +name. In the example above, the first stat value for ``nvme0n1`` is +255999 in both files. + +The sysfs ``stat`` file is efficient for monitoring a small, known set +of disks. If you're tracking a large number of devices, +``/proc/diskstats`` is often the better choice since it avoids the +overhead of opening and closing multiple files for each snapshot. + +All fields are cumulative, monotonic counters, except for field 9, which +resets to zero as I/Os complete. The remaining fields reset at boot, on +device reattachment or reinitialization, or when the underlying counter +overflows. Applications reading these counters should detect and handle +resets when comparing stat snapshots. Each set of stats only applies to the indicated device; if you want system-wide stats you'll have to find all the devices and sum them all up. diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst index 5376890adbeb..1f7f14c6e184 100644 --- a/Documentation/admin-guide/kdump/kdump.rst +++ b/Documentation/admin-guide/kdump/kdump.rst @@ -180,10 +180,6 @@ Dump-capture kernel config options (Arch Dependent, i386 and x86_64) 1) On i386, enable high memory support under "Processor type and features":: - CONFIG_HIGHMEM64G=y - - or:: - CONFIG_HIGHMEM4G 2) With CONFIG_SMP=y, usually nr_cpus=1 need specified on the kernel diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb8752b42ec8..bc24adc4d228 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -416,10 +416,6 @@ Format: { quiet (default) | verbose | debug } Change the amount of debugging information output when initialising the APIC and IO-APIC components. - For X86-32, this can also be used to specify an APIC - driver name. - Format: apic=driver_name - Examples: apic=bigsmp apic_extnmi= [APIC,X86,EARLY] External NMI delivery setting Format: { bsp (default) | all | none } @@ -1785,7 +1781,9 @@ allocation boundaries as a proactive defense against bounds-checking flaws in the kernel's copy_to_user()/copy_from_user() interface. - on Perform hardened usercopy checks (default). + The default is determined by + CONFIG_HARDENED_USERCOPY_DEFAULT_ON. + on Perform hardened usercopy checks. off Disable hardened usercopy checks. hardlockup_all_cpu_backtrace= @@ -5758,6 +5756,11 @@ rcutorture.test_boost_duration= [KNL] Duration (s) of each individual boost test. + rcutorture.test_boost_holdoff= [KNL] + Holdoff time (s) from start of test to the start + of RCU priority-boost testing. Defaults to zero, + that is, no holdoff. + rcutorture.test_boost_interval= [KNL] Interval (s) between each boost test. @@ -6082,7 +6085,7 @@ is assumed to be I/O ports; otherwise it is memory. reserve_mem= [RAM] - Format: nn[KNG]:<align>:<label> + Format: nn[KMG]:<align>:<label> Reserve physical memory and label it with a name that other subsystems can use to access it. This is typically used for systems that do not wipe the RAM, and this command @@ -6582,6 +6585,8 @@ Selecting 'on' will also enable the mitigation against user space to user space task attacks. + Selecting specific mitigation does not force enable + user mitigations. Selecting 'off' will disable both the kernel and the user space protections. @@ -7672,13 +7677,6 @@ 16 - SIGBUS faults Example: user_debug=31 - userpte= - [X86,EARLY] Flags controlling user PTE allocations. - - nohigh = do not allocate PTE pages in - HIGHMEM regardless of setting - of CONFIG_HIGHPTE. - vdso= [X86,SH,SPARC] On X86_32, this is an alias for vdso32=. Otherwise: diff --git a/Documentation/admin-guide/pm/cpufreq.rst b/Documentation/admin-guide/pm/cpufreq.rst index a21369eba034..3950583f2b15 100644 --- a/Documentation/admin-guide/pm/cpufreq.rst +++ b/Documentation/admin-guide/pm/cpufreq.rst @@ -248,6 +248,20 @@ are the following: If that frequency cannot be determined, this attribute should not be present. +``cpuinfo_avg_freq`` + An average frequency (in KHz) of all CPUs belonging to a given policy, + derived from a hardware provided feedback and reported on a time frame + spanning at most few milliseconds. + + This is expected to be based on the frequency the hardware actually runs + at and, as such, might require specialised hardware support (such as AMU + extension on ARM). If one cannot be determined, this attribute should + not be present. + + Note, that failed attempt to retrieve current frequency for a given + CPU(s) will result in an appropriate error, i.e: EAGAIN for CPU that + remains idle (raised on ARM). + ``cpuinfo_max_freq`` Maximum possible operating frequency the CPUs belonging to this policy can run at (in kHz). @@ -293,7 +307,8 @@ are the following: Some architectures (e.g. ``x86``) may attempt to provide information more precisely reflecting the current CPU frequency through this attribute, but that still may not be the exact current CPU frequency as - seen by the hardware at the moment. + seen by the hardware at the moment. This behavior though, is only + available via c:macro:``CPUFREQ_ARCH_CUR_FREQ`` option. ``scaling_driver`` The scaling driver currently in use. diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index a43b78b4b646..dd49a89a62d3 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -212,6 +212,17 @@ pid>/``). This value defaults to 0. +core_sort_vma +============= + +The default coredump writes VMAs in address order. By setting +``core_sort_vma`` to 1, VMAs will be written from smallest size +to largest size. This is known to break at least elfutils, but +can be handy when dealing with very large (and truncated) +coredumps where the more useful debugging details are included +in the smaller VMAs. + + core_uses_pid ============= diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index 2ed79f41a411..d0502691dfa1 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -28,7 +28,7 @@ should be a userspace tool that handles all the low-level details, keeps a database of the authorized devices and prompts users for new connections. More details about the sysfs interface for Thunderbolt devices can be -found in ``Documentation/ABI/testing/sysfs-bus-thunderbolt``. +found in Documentation/ABI/testing/sysfs-bus-thunderbolt. Those users who just want to connect any device without any sort of manual work can add following line to diff --git a/Documentation/admin-guide/workload-tracing.rst b/Documentation/admin-guide/workload-tracing.rst index 6be38c1b9c5b..d6313890ee41 100644 --- a/Documentation/admin-guide/workload-tracing.rst +++ b/Documentation/admin-guide/workload-tracing.rst @@ -82,7 +82,7 @@ Install tools to build Linux kernel and tools in kernel repository. scripts/ver_linux is a good way to check if your system already has the necessary tools:: - sudo apt-get build-essentials flex bison yacc + sudo apt-get install build-essential flex bison yacc sudo apt install libelf-dev systemtap-sdt-dev libslang2-dev libperl-dev libdw-dev cscope is a good tool to browse kernel sources. Let's install it now:: |