diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/README.rst | 6 | ||||
| -rw-r--r-- | Documentation/admin-guide/bcache.rst | 31 | ||||
| -rw-r--r-- | Documentation/admin-guide/blockdev/ramdisk.rst | 66 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/cpusets.rst | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/kdump/kdump.rst | 7 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 38 | ||||
| -rw-r--r-- | Documentation/admin-guide/svga.rst | 7 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/abi.rst | 73 | ||||
| -rw-r--r-- | Documentation/admin-guide/tainted-kernels.rst | 2 |
9 files changed, 98 insertions, 134 deletions
diff --git a/Documentation/admin-guide/README.rst b/Documentation/admin-guide/README.rst index 5aad534233cd..95a28f47ac30 100644 --- a/Documentation/admin-guide/README.rst +++ b/Documentation/admin-guide/README.rst @@ -322,9 +322,9 @@ Compiling the kernel reboot, and enjoy! If you ever need to change the default root device, video mode, - ramdisk size, etc. in the kernel image, use the ``rdev`` program (or - alternatively the LILO boot options when appropriate). No need to - recompile the kernel to change these parameters. + etc. in the kernel image, use your bootloader's boot options + where appropriate. No need to recompile the kernel to change + these parameters. - Reboot with the new kernel and enjoy. diff --git a/Documentation/admin-guide/bcache.rst b/Documentation/admin-guide/bcache.rst index 1eccf952876d..8d3a2d045c0a 100644 --- a/Documentation/admin-guide/bcache.rst +++ b/Documentation/admin-guide/bcache.rst @@ -5,11 +5,14 @@ A block layer cache (bcache) Say you've got a big slow raid 6, and an ssd or three. Wouldn't it be nice if you could use them as cache... Hence bcache. -Wiki and git repositories are at: +The bcache wiki can be found at: + https://bcache.evilpiepirate.org - - https://bcache.evilpiepirate.org - - http://evilpiepirate.org/git/linux-bcache.git - - https://evilpiepirate.org/git/bcache-tools.git +This is the git repository of bcache-tools: + https://git.kernel.org/pub/scm/linux/kernel/git/colyli/bcache-tools.git/ + +The latest bcache kernel code can be found from mainline Linux kernel: + https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ It's designed around the performance characteristics of SSDs - it only allocates in erase block sized buckets, and it uses a hybrid btree/log to track cached @@ -41,17 +44,21 @@ in the cache it first disables writeback caching and waits for all dirty data to be flushed. Getting started: -You'll need make-bcache from the bcache-tools repository. Both the cache device +You'll need bcache util from the bcache-tools repository. Both the cache device and backing device must be formatted before use:: - make-bcache -B /dev/sdb - make-bcache -C /dev/sdc + bcache make -B /dev/sdb + bcache make -C /dev/sdc -make-bcache has the ability to format multiple devices at the same time - if +`bcache make` has the ability to format multiple devices at the same time - if you format your backing devices and cache device at the same time, you won't have to manually attach:: - make-bcache -B /dev/sda /dev/sdb -C /dev/sdc + bcache make -B /dev/sda /dev/sdb -C /dev/sdc + +If your bcache-tools is not updated to latest version and does not have the +unified `bcache` utility, you may use the legacy `make-bcache` utility to format +bcache device with same -B and -C parameters. bcache-tools now ships udev rules, and bcache devices are known to the kernel immediately. Without udev, you can manually register devices like this:: @@ -188,7 +195,7 @@ D) Recovering data without bcache: If bcache is not available in the kernel, a filesystem on the backing device is still available at an 8KiB offset. So either via a loopdev of the backing device created with --offset 8K, or any value defined by ---data-offset when you originally formatted bcache with `make-bcache`. +--data-offset when you originally formatted bcache with `bcache make`. For example:: @@ -210,7 +217,7 @@ E) Wiping a cache device After you boot back with bcache enabled, you recreate the cache and attach it:: - host:~# make-bcache -C /dev/sdh2 + host:~# bcache make -C /dev/sdh2 UUID: 7be7e175-8f4c-4f99-94b2-9c904d227045 Set UUID: 5bc072a8-ab17-446d-9744-e247949913c1 version: 0 @@ -318,7 +325,7 @@ want for getting the best possible numbers when benchmarking. The default metadata size in bcache is 8k. If your backing device is RAID based, then be sure to align this by a multiple of your stride - width using `make-bcache --data-offset`. If you intend to expand your + width using `bcache make --data-offset`. If you intend to expand your disk array in the future, then multiply a series of primes by your raid stripe size to get the disk multiples that you would like. diff --git a/Documentation/admin-guide/blockdev/ramdisk.rst b/Documentation/admin-guide/blockdev/ramdisk.rst index b7c2268f8dec..9ce6101e8dd9 100644 --- a/Documentation/admin-guide/blockdev/ramdisk.rst +++ b/Documentation/admin-guide/blockdev/ramdisk.rst @@ -6,7 +6,7 @@ Using the RAM disk block device with Linux 1) Overview 2) Kernel Command Line Parameters - 3) Using "rdev -r" + 3) Using "rdev" 4) An Example of Creating a Compressed RAM Disk @@ -59,51 +59,27 @@ default is 4096 (4 MB). rd_size See ramdisk_size. -3) Using "rdev -r" ------------------- +3) Using "rdev" +--------------- -The usage of the word (two bytes) that "rdev -r" sets in the kernel image is -as follows. The low 11 bits (0 -> 10) specify an offset (in 1 k blocks) of up -to 2 MB (2^11) of where to find the RAM disk (this used to be the size). Bit -14 indicates that a RAM disk is to be loaded, and bit 15 indicates whether a -prompt/wait sequence is to be given before trying to read the RAM disk. Since -the RAM disk dynamically grows as data is being written into it, a size field -is not required. Bits 11 to 13 are not currently used and may as well be zero. -These numbers are no magical secrets, as seen below:: +"rdev" is an obsolete, deprecated, antiquated utility that could be used +to set the boot device in a Linux kernel image. - ./arch/x86/kernel/setup.c:#define RAMDISK_IMAGE_START_MASK 0x07FF - ./arch/x86/kernel/setup.c:#define RAMDISK_PROMPT_FLAG 0x8000 - ./arch/x86/kernel/setup.c:#define RAMDISK_LOAD_FLAG 0x4000 +Instead of using rdev, just place the boot device information on the +kernel command line and pass it to the kernel from the bootloader. -Consider a typical two floppy disk setup, where you will have the -kernel on disk one, and have already put a RAM disk image onto disk #2. +You can also pass arguments to the kernel by setting FDARGS in +arch/x86/boot/Makefile and specify in initrd image by setting FDINITRD in +arch/x86/boot/Makefile. -Hence you want to set bits 0 to 13 as 0, meaning that your RAM disk -starts at an offset of 0 kB from the beginning of the floppy. -The command line equivalent is: "ramdisk_start=0" +Some of the kernel command line boot options that may apply here are:: -You want bit 14 as one, indicating that a RAM disk is to be loaded. -The command line equivalent is: "load_ramdisk=1" - -You want bit 15 as one, indicating that you want a prompt/keypress -sequence so that you have a chance to switch floppy disks. -The command line equivalent is: "prompt_ramdisk=1" - -Putting that together gives 2^15 + 2^14 + 0 = 49152 for an rdev word. -So to create disk one of the set, you would do:: - - /usr/src/linux# cat arch/x86/boot/zImage > /dev/fd0 - /usr/src/linux# rdev /dev/fd0 /dev/fd0 - /usr/src/linux# rdev -r /dev/fd0 49152 + ramdisk_start=N + ramdisk_size=M If you make a boot disk that has LILO, then for the above, you would use:: - append = "ramdisk_start=0 load_ramdisk=1 prompt_ramdisk=1" - -Since the default start = 0 and the default prompt = 1, you could use:: - - append = "load_ramdisk=1" - + append = "ramdisk_start=N ramdisk_size=M" 4) An Example of Creating a Compressed RAM Disk ----------------------------------------------- @@ -151,12 +127,9 @@ f) Put the RAM disk image onto the floppy, after the kernel. Use an offset dd if=/tmp/ram_image.gz of=/dev/fd0 bs=1k seek=400 -g) Use "rdev" to set the boot device, RAM disk offset, prompt flag, etc. - For prompt_ramdisk=1, load_ramdisk=1, ramdisk_start=400, one would - have 2^15 + 2^14 + 400 = 49552:: - - rdev /dev/fd0 /dev/fd0 - rdev -r /dev/fd0 49552 +g) Make sure that you have already specified the boot information in + FDARGS and FDINITRD or that you use a bootloader to pass kernel + command line boot options to the kernel. That is it. You now have your boot/root compressed RAM disk floppy. Some users may wish to combine steps (d) and (f) by using a pipe. @@ -167,11 +140,14 @@ users may wish to combine steps (d) and (f) by using a pipe. Changelog: ---------- +SEPT-2020 : + + Removed usage of "rdev" + 10-22-04 : Updated to reflect changes in command line options, remove obsolete references, general cleanup. James Nelson (james4765@gmail.com) - 12-95 : Original Document diff --git a/Documentation/admin-guide/cgroup-v1/cpusets.rst b/Documentation/admin-guide/cgroup-v1/cpusets.rst index 7ade3abd342a..5d844ed4df69 100644 --- a/Documentation/admin-guide/cgroup-v1/cpusets.rst +++ b/Documentation/admin-guide/cgroup-v1/cpusets.rst @@ -1,3 +1,5 @@ +.. _cpusets: + ======= CPUSETS ======= diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst index 2da65fef2a1c..75a9dd98e76e 100644 --- a/Documentation/admin-guide/kdump/kdump.rst +++ b/Documentation/admin-guide/kdump/kdump.rst @@ -509,9 +509,12 @@ ELF32-format headers using the --elf32-core-headers kernel option on the dump kernel. You can also use the Crash utility to analyze dump files in Kdump -format. Crash is available on Dave Anderson's site at the following URL: +format. Crash is available at the following URL: - http://people.redhat.com/~anderson/ + https://github.com/crash-utility/crash + +Crash document can be found at: + https://crash-utility.github.io/ Trigger Kdump on WARN() ======================= diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index ffe864390c5a..0fa47ddf4c46 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -591,7 +591,7 @@ some critical bits. cma=nn[MG]@[start[MG][-end[MG]]] - [ARM,X86,KNL] + [KNL,CMA] Sets the size of kernel global memory area for contiguous memory allocations and optionally the placement constraint by the physical address range of @@ -940,7 +940,7 @@ Arch Perfmon v4 (Skylake and newer). disable_ddw [PPC/PSERIES] - Disable Dynamic DMA Window support. Use this if + Disable Dynamic DMA Window support. Use this to workaround buggy firmware. disable_ipv6= [IPV6] @@ -1019,7 +1019,7 @@ what data is available or for reverse-engineering. dyndbg[="val"] [KNL,DYNAMIC_DEBUG] - module.dyndbg[="val"] + <module>.dyndbg[="val"] Enable debug messages at boot time. See Documentation/admin-guide/dynamic-debug-howto.rst for details. @@ -1027,7 +1027,7 @@ nopku [X86] Disable Memory Protection Keys CPU feature found in some Intel CPUs. - module.async_probe [KNL] + <module>.async_probe [KNL] Enable asynchronous probe on this module. early_ioremap_debug [KNL] @@ -1956,7 +1956,7 @@ 1 - Bypass the IOMMU for DMA. unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH. - io7= [HW] IO7 for Marvel based alpha systems + io7= [HW] IO7 for Marvel-based Alpha systems See comment before marvel_specify_io7 in arch/alpha/kernel/core_marvel.c. @@ -2177,7 +2177,7 @@ kgdbwait [KGDB] Stop kernel execution and enter the kernel debugger at the earliest opportunity. - kmac= [MIPS] korina ethernet MAC address. + kmac= [MIPS] Korina ethernet MAC address. Configure the RouterBoard 532 series on-chip Ethernet adapter MAC address. @@ -2258,6 +2258,14 @@ [KVM,ARM] Allow use of GICv4 for direct injection of LPIs. + kvm_cma_resv_ratio=n [PPC] + Reserves given percentage from system memory area for + contiguous memory allocation for KVM hash pagetable + allocation. + By default it reserves 5% of total system memory. + Format: <integer> + Default: 5 + kvm-intel.ept= [KVM,Intel] Disable extended page tables (virtualized MMU) support on capable Intel chips. Default is 1 (enabled) @@ -2367,9 +2375,10 @@ lapic [X86-32,APIC] Enable the local APIC even if BIOS disabled it. - lapic= [X86,APIC] "notscdeadline" Do not use TSC deadline + lapic= [X86,APIC] Do not use TSC deadline value for LAPIC timer one-shot implementation. Default back to the programmable timer unit in the LAPIC. + Format: notscdeadline lapic_timer_c2_ok [X86,APIC] trust the local apic timer in C2 power state. @@ -2441,8 +2450,7 @@ memblock=debug [KNL] Enable memblock debug messages. - load_ramdisk= [RAM] List of ramdisks to load from floppy - See Documentation/admin-guide/blockdev/ramdisk.rst. + load_ramdisk= [RAM] [Deprecated] lockd.nlm_grace_period=P [NFS] Assign grace period. Format: <integer> @@ -2579,8 +2587,8 @@ (machvec) in a generic kernel. Example: machvec=hpzx1 - machtype= [Loongson] Share the same kernel image file between different - yeeloong laptop. + machtype= [Loongson] Share the same kernel image file between + different yeeloong laptops. Example: machtype=lemote-yeeloong-2f-7inch max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater @@ -3185,7 +3193,7 @@ register save and restore. The kernel will only save legacy floating-point registers on task switch. - nohugeiomap [KNL,X86,PPC] Disable kernel huge I/O mappings. + nohugeiomap [KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings. nosmt [KNL,S390] Disable symmetric multithreading (SMT). Equivalent to smt=1. @@ -3921,9 +3929,7 @@ Param: <number> - step/bucket size as a power of 2 for statistical time based profiling. - prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk - before loading. - See Documentation/admin-guide/blockdev/ramdisk.rst. + prompt_ramdisk= [RAM] [Deprecated] prot_virt= [S390] enable hosting protected virtual machines isolated from the hypervisor (if hardware supports @@ -3981,6 +3987,8 @@ ramdisk_size= [RAM] Sizes of RAM disks in kilobytes See Documentation/admin-guide/blockdev/ramdisk.rst. + ramdisk_start= [RAM] RAM disk image start address + random.trust_cpu={on,off} [KNL] Enable or disable trusting the use of the CPU's random number generator (if available) to diff --git a/Documentation/admin-guide/svga.rst b/Documentation/admin-guide/svga.rst index b6c2f9acca92..9eb1e0738e84 100644 --- a/Documentation/admin-guide/svga.rst +++ b/Documentation/admin-guide/svga.rst @@ -12,7 +12,8 @@ Intro This small document describes the "Video Mode Selection" feature which allows the use of various special video modes supported by the video BIOS. Due to usage of the BIOS, the selection is limited to boot time (before the -kernel decompression starts) and works only on 80X86 machines. +kernel decompression starts) and works only on 80X86 machines that are +booted through BIOS firmware (as opposed to through UEFI, kexec, etc.). .. note:: @@ -23,7 +24,7 @@ kernel decompression starts) and works only on 80X86 machines. The video mode to be used is selected by a kernel parameter which can be specified in the kernel Makefile (the SVGA_MODE=... line) or by the "vga=..." -option of LILO (or some other boot loader you use) or by the "vidmode" utility +option of LILO (or some other boot loader you use) or by the "xrandr" utility (present in standard Linux utility packages). You can use the following values of this parameter:: @@ -41,7 +42,7 @@ of this parameter:: better to use absolute mode numbers instead. 0x.... - Hexadecimal video mode ID (also displayed on the menu, see below - for exact meaning of the ID). Warning: rdev and LILO don't support + for exact meaning of the ID). Warning: LILO doesn't support hexadecimal numbers -- you have to convert it to decimal manually. Menu diff --git a/Documentation/admin-guide/sysctl/abi.rst b/Documentation/admin-guide/sysctl/abi.rst index 599bcde7f0b7..ac87eafdb54f 100644 --- a/Documentation/admin-guide/sysctl/abi.rst +++ b/Documentation/admin-guide/sysctl/abi.rst @@ -1,67 +1,34 @@ +.. SPDX-License-Identifier: GPL-2.0+ + ================================ Documentation for /proc/sys/abi/ ================================ -kernel version 2.6.0.test2 +.. See scripts/check-sysctl-docs to keep this up to date: +.. scripts/check-sysctl-docs -vtable="abi" \ +.. Documentation/admin-guide/sysctl/abi.rst \ +.. $(git grep -l register_sysctl_) -Copyright (c) 2003, Fabian Frederick <ffrederick@users.sourceforge.net> +Copyright (c) 2020, Stephen Kitt -For general info: index.rst. +For general info, see :doc:`index`. ------------------------------------------------------------------------------ -This path is binary emulation relevant aka personality types aka abi. -When a process is executed, it's linked to an exec_domain whose -personality is defined using values available from /proc/sys/abi. -You can find further details about abi in include/linux/personality.h. - -Here are the files featuring in 2.6 kernel: - -- defhandler_coff -- defhandler_elf -- defhandler_lcall7 -- defhandler_libcso -- fake_utsname -- trace - -defhandler_coff ---------------- - -defined value: - PER_SCOSVR3:: - - 0x0003 | STICKY_TIMEOUTS | WHOLE_SECONDS | SHORT_INODE - -defhandler_elf --------------- - -defined value: - PER_LINUX:: - - 0 - -defhandler_lcall7 ------------------ - -defined value : - PER_SVR4:: - - 0x0001 | STICKY_TIMEOUTS | MMAP_PAGE_ZERO, - -defhandler_libsco ------------------ - -defined value: - PER_SVR4:: +The files in ``/proc/sys/abi`` can be used to see and modify +ABI-related settings. - 0x0001 | STICKY_TIMEOUTS | MMAP_PAGE_ZERO, +Currently, these files might (depending on your configuration) +show up in ``/proc/sys/kernel``: -fake_utsname ------------- +.. contents:: :local: -Unused +vsyscall32 (x86) +================ -trace ------ +Determines whether the kernels maps a vDSO page into 32-bit processes; +can be set to 1 to enable, or 0 to disable. Defaults to enabled if +``CONFIG_COMPAT_VDSO`` is set, disabled otherwide. -Unused +This controls the same setting as the ``vdso32`` kernel boot +parameter. diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst index abf804719890..f718a2eaf1f6 100644 --- a/Documentation/admin-guide/tainted-kernels.rst +++ b/Documentation/admin-guide/tainted-kernels.rst @@ -130,7 +130,7 @@ More detailed explanation for tainting 5) ``B`` If a page-release function has found a bad page reference or some unexpected page flags. This indicates a hardware problem or a kernel bug; there should be other information in the log indicating why this tainting - occured. + occurred. 6) ``U`` if a user or user application specifically requested that the Tainted flag be set, ``' '`` otherwise. |