diff options
Diffstat (limited to 'Documentation/admin-guide')
36 files changed, 674 insertions, 172 deletions
diff --git a/Documentation/admin-guide/abi-obsolete.rst b/Documentation/admin-guide/abi-obsolete.rst index d095867899c5..594e697aa1b2 100644 --- a/Documentation/admin-guide/abi-obsolete.rst +++ b/Documentation/admin-guide/abi-obsolete.rst @@ -7,5 +7,5 @@ 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 The description of the interface will document the reason why it is obsolete and when it can be expected to be removed.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:: $srctree/Documentation/ABI/obsolete +.. kernel-abi:: ABI/obsolete :rst: diff --git a/Documentation/admin-guide/abi-removed.rst b/Documentation/admin-guide/abi-removed.rst index f7e9e43023c1..f9e000c81828 100644 --- a/Documentation/admin-guide/abi-removed.rst +++ b/Documentation/admin-guide/abi-removed.rst @@ -1,5 +1,5 @@ ABI removed symbols =================== -.. kernel-abi:: $srctree/Documentation/ABI/removed +.. kernel-abi:: ABI/removed :rst: diff --git a/Documentation/admin-guide/abi-stable.rst b/Documentation/admin-guide/abi-stable.rst index 70490736e0d3..fc3361d847b1 100644 --- a/Documentation/admin-guide/abi-stable.rst +++ b/Documentation/admin-guide/abi-stable.rst @@ -10,5 +10,5 @@ for at least 2 years. Most interfaces (like syscalls) are expected to never change and always be available. -.. kernel-abi:: $srctree/Documentation/ABI/stable +.. kernel-abi:: ABI/stable :rst: diff --git a/Documentation/admin-guide/abi-testing.rst b/Documentation/admin-guide/abi-testing.rst index b205b16a72d0..19767926b344 100644 --- a/Documentation/admin-guide/abi-testing.rst +++ b/Documentation/admin-guide/abi-testing.rst @@ -16,5 +16,5 @@ 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:: $srctree/Documentation/ABI/testing +.. kernel-abi:: ABI/testing :rst: diff --git a/Documentation/admin-guide/acpi/cppc_sysfs.rst b/Documentation/admin-guide/acpi/cppc_sysfs.rst index e53d76365aa7..36981c667823 100644 --- a/Documentation/admin-guide/acpi/cppc_sysfs.rst +++ b/Documentation/admin-guide/acpi/cppc_sysfs.rst @@ -75,4 +75,4 @@ taking two different snapshots of feedback counters at time T1 and T2. delivered_counter_delta = fbc_t2[del] - fbc_t1[del] reference_counter_delta = fbc_t2[ref] - fbc_t1[ref] - delivered_perf = (refernce_perf x delivered_counter_delta) / reference_counter_delta + delivered_perf = (reference_perf x delivered_counter_delta) / reference_counter_delta diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index e4551579cb12..ee2b0030d416 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -328,7 +328,7 @@ as idle:: From now on, any pages on zram are idle pages. The idle mark will be removed until someone requests access of the block. IOW, unless there is access request, those pages are still idle pages. -Additionally, when CONFIG_ZRAM_MEMORY_TRACKING is enabled pages can be +Additionally, when CONFIG_ZRAM_TRACK_ENTRY_ACTIME is enabled pages can be marked as idle based on how long (in seconds) it's been since they were last accessed:: diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 3f85254f3cef..17e6e9565156 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1093,7 +1093,11 @@ All time durations are in microseconds. A read-write single value file which exists on non-root cgroups. The default is "100". - The weight in the range [1, 10000]. + For non idle groups (cpu.idle = 0), the weight is in the + range [1, 10000]. + + If the cgroup has been configured to be SCHED_IDLE (cpu.idle = 1), + then the weight will show as a 0. cpu.weight.nice A read-write single value file which exists on non-root @@ -1157,6 +1161,16 @@ All time durations are in microseconds. values similar to the sched_setattr(2). This maximum utilization value is used to clamp the task specific maximum utilization clamp. + cpu.idle + A read-write single value file which exists on non-root cgroups. + The default is 0. + + This is the cgroup analog of the per-task SCHED_IDLE sched policy. + Setting this value to a 1 will make the scheduling policy of the + cgroup SCHED_IDLE. The threads inside the cgroup will retain their + own relative priorities, but the cgroup itself will be treated as + very low priority relative to its peers. + Memory @@ -1679,6 +1693,21 @@ PAGE_SIZE multiple when read back. limit, it will refuse to take any more stores before existing entries fault back in or are written out to disk. + memory.zswap.writeback + A read-write single value file. The default value is "1". The + initial value of the root cgroup is 1, and when a new cgroup is + created, it inherits the current value of its parent. + + When this is set to 0, all swapping attempts to swapping devices + are disabled. This included both zswap writebacks, and swapping due + to zswap store failures. If the zswap store failures are recurring + (for e.g if the pages are incompressible), users can observe + reclaim inefficiency after disabling writeback (because the same + pages might be rejected again and again). + + Note that this is subtly different from setting memory.swap.max to + 0, as it still allows for pages to be written to the zswap pool. + memory.pressure A read-only nested-keyed file. @@ -2316,6 +2345,13 @@ Cpuset Interface Files treated to have an implicit value of "cpuset.cpus" in the formation of local partition. + cpuset.cpus.isolated + A read-only and root cgroup only multiple values file. + + This file shows the set of all isolated CPUs used in existing + isolated partitions. It will be empty if no isolated partition + is created. + 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 @@ -2358,11 +2394,11 @@ Cpuset Interface Files 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 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. + When set to "isolated", the CPUs in that partition will be in + an isolated state without any load balancing from the scheduler + and excluded from the unbound workqueues. Tasks placed in such + a partition with multiple CPUs should be carefully distributed + and bound to each of the individual CPUs for optimal performance. A partition root ("root" or "isolated") can be in one of the two possible states - valid or invalid. An invalid partition diff --git a/Documentation/admin-guide/cifs/todo.rst b/Documentation/admin-guide/cifs/todo.rst index 2646ed2e2d3e..9a65c670774e 100644 --- a/Documentation/admin-guide/cifs/todo.rst +++ b/Documentation/admin-guide/cifs/todo.rst @@ -2,7 +2,8 @@ TODO ==== -Version 2.14 December 21, 2018 +As of 6.7 kernel. See https://wiki.samba.org/index.php/LinuxCIFSKernel +for list of features added by release A Partial List of Missing Features ================================== @@ -12,22 +13,22 @@ for visible, important contributions to this module. Here is a partial list of the known problems and missing features: a) SMB3 (and SMB3.1.1) missing optional features: + multichannel performance optimizations, algorithmic channel selection, + directory leases optimizations, + support for faster packet signing (GMAC), + support for compression over the network, + T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl + are currently the only two server side copy mechanisms supported) - - multichannel (partially integrated), integration of multichannel with RDMA - - directory leases (improved metadata caching). Currently only implemented for root dir - - T10 copy offload ie "ODX" (copy chunk, and "Duplicate Extents" ioctl - currently the only two server side copy mechanisms supported) +b) Better optimized compounding and error handling for sparse file support, + perhaps addition of new optional SMB3.1.1 fsctls to make collapse range + and insert range more atomic -b) improved sparse file support (fiemap and SEEK_HOLE are implemented - but additional features would be supportable by the protocol such - as FALLOC_FL_COLLAPSE_RANGE and FALLOC_FL_INSERT_RANGE) - -c) Directory entry caching relies on a 1 second timer, rather than - using Directory Leases, currently only the root file handle is cached longer - by leveraging Directory Leases +c) Support for SMB3.1.1 over QUIC (and perhaps other socket based protocols + like SCTP) d) quota support (needs minor kernel change since quota calls otherwise - won't make it to network filesystems or deviceless filesystems). + won't make it to network filesystems or deviceless filesystems). e) Additional use cases can be optimized to use "compounding" (e.g. open/query/close and open/setinfo/close) to reduce the number of @@ -92,23 +93,20 @@ t) split cifs and smb3 support into separate modules so legacy (and less v) Additional testing of POSIX Extensions for SMB3.1.1 -w) Add support for additional strong encryption types, and additional spnego - authentication mechanisms (see MS-SMB2). GCM-256 is now partially implemented. +w) Support for the Mac SMB3.1.1 extensions to improve interop with Apple servers + +x) Support for additional authentication options (e.g. IAKERB, peer-to-peer + Kerberos, SCRAM and others supported by existing servers) -x) Finish support for SMB3.1.1 compression +y) Improved tracing, more eBPF trace points, better scripts for performance + analysis Known Bugs ========== See https://bugzilla.samba.org - search on product "CifsVFS" for current bug list. Also check http://bugzilla.kernel.org (Product = File System, Component = CIFS) - -1) existing symbolic links (Windows reparse points) are recognized but - can not be created remotely. They are implemented for Samba and those that - support the CIFS Unix extensions, although earlier versions of Samba - overly restrict the pathnames. -2) follow_link and readdir code does not follow dfs junctions - but recognizes them +and xfstest results e.g. https://wiki.samba.org/index.php/Xfstest-results-smb3 Misc testing to do ================== diff --git a/Documentation/admin-guide/cifs/usage.rst b/Documentation/admin-guide/cifs/usage.rst index 5f936b4b6018..aa8290a29dc8 100644 --- a/Documentation/admin-guide/cifs/usage.rst +++ b/Documentation/admin-guide/cifs/usage.rst @@ -81,7 +81,7 @@ much older and less secure than the default dialect SMB3 which includes many advanced security features such as downgrade attack detection and encrypted shares and stronger signing and authentication algorithms. There are additional mount options that may be helpful for SMB3 to get -improved POSIX behavior (NB: can use vers=3.0 to force only SMB3, never 2.1): +improved POSIX behavior (NB: can use vers=3 to force SMB3 or later, never 2.1): ``mfsymlinks`` and either ``cifsacl`` or ``modefromsid`` (usually with ``idsfromsid``) @@ -715,6 +715,7 @@ DebugData Displays information about active CIFS sessions and Stats Lists summary resource usage information as well as per share statistics. open_files List all the open file handles on all active SMB sessions. +mount_params List of all mount parameters available for the module ======================= ======================================================= Configuration pseudo-files: @@ -864,6 +865,11 @@ i.e.:: echo "value" > /sys/module/cifs/parameters/<param> +More detailed descriptions of the available module parameters and their values +can be seen by doing: + + modinfo cifs (or modinfo smb3) + ================= ========================================================== 1. enable_oplocks Enable or disable oplocks. Oplocks are enabled by default. [Y/y/1]. To disable use any of [N/n/0]. diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt index 839054923530..94c98be1329a 100644 --- a/Documentation/admin-guide/devices.txt +++ b/Documentation/admin-guide/devices.txt @@ -2704,6 +2704,9 @@ ... 185 = /dev/ttyNX15 Hilscher netX serial port 15 186 = /dev/ttyJ0 JTAG1 DCC protocol based serial port emulation + + If maximum number of uartlite serial ports is more than 4, then the driver + uses dynamic allocation instead of static allocation for major number. 187 = /dev/ttyUL0 Xilinx uartlite - port 0 ... 190 = /dev/ttyUL3 Xilinx uartlite - port 3 diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst index 0c526dac8428..0e9b48daf690 100644 --- a/Documentation/admin-guide/dynamic-debug-howto.rst +++ b/Documentation/admin-guide/dynamic-debug-howto.rst @@ -321,13 +321,13 @@ Examples :#> ddcmd 'format "nfsd: READ" +p' // enable messages in files of which the paths include string "usb" - :#> ddcmd 'file *usb* +p' > /proc/dynamic_debug/control + :#> ddcmd 'file *usb* +p' // enable all messages - :#> ddcmd '+p' > /proc/dynamic_debug/control + :#> ddcmd '+p' // add module, function to all enabled messages - :#> ddcmd '+mf' > /proc/dynamic_debug/control + :#> ddcmd '+mf' // boot-args example, with newlines and comments for readability Kernel command line: ... diff --git a/Documentation/admin-guide/features.rst b/Documentation/admin-guide/features.rst index 8c167082a84f..7651eca38227 100644 --- a/Documentation/admin-guide/features.rst +++ b/Documentation/admin-guide/features.rst @@ -1,3 +1,3 @@ .. SPDX-License-Identifier: GPL-2.0 -.. kernel-feat:: $srctree/Documentation/features +.. kernel-feat:: features diff --git a/Documentation/admin-guide/hw_random.rst b/Documentation/admin-guide/hw_random.rst index d494601717f1..bfc39f1cf470 100644 --- a/Documentation/admin-guide/hw_random.rst +++ b/Documentation/admin-guide/hw_random.rst @@ -14,10 +14,9 @@ into that core. To make the most effective use of these mechanisms, you should download the support software as well. Download the -latest version of the "rng-tools" package from the -hw_random driver's official Web site: +latest version of the "rng-tools" package from: - http://sourceforge.net/projects/gkernel/ + https://github.com/nhorman/rng-tools Those tools use /dev/hwrng to fill the kernel entropy pool, which is used internally and exported by the /dev/urandom and diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst index 43ea35613dfc..fb40a1f6f79e 100644 --- a/Documentation/admin-guide/index.rst +++ b/Documentation/admin-guide/index.rst @@ -119,6 +119,7 @@ configure specific aspects of kernel behavior to your liking. parport perf-security pm/index + pmf pnp rapidio ras diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 78e4d2e7ba14..bced9e4b6e08 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -172,7 +172,7 @@ variables. Offset of the free_list's member. This value is used to compute the number of free pages. -Each zone has a free_area structure array called free_area[MAX_ORDER + 1]. +Each zone has a free_area structure array called free_area[NR_PAGE_ORDERS]. The free_list represents a linked list of free page blocks. (list_head, next|prev) @@ -189,11 +189,11 @@ Offsets of the vmap_area's members. They carry vmalloc-specific information. Makedumpfile gets the start address of the vmalloc region from this. -(zone.free_area, MAX_ORDER + 1) -------------------------------- +(zone.free_area, NR_PAGE_ORDERS) +-------------------------------- Free areas descriptor. User-space tools use this value to iterate the -free_area ranges. MAX_ORDER is used by the zone buddy allocator. +free_area ranges. NR_PAGE_ORDERS is used by the zone buddy allocator. prb --- diff --git a/Documentation/admin-guide/kernel-parameters.rst b/Documentation/admin-guide/kernel-parameters.rst index 102937bc8443..4410384596a9 100644 --- a/Documentation/admin-guide/kernel-parameters.rst +++ b/Documentation/admin-guide/kernel-parameters.rst @@ -218,8 +218,3 @@ bytes respectively. Such letter suffixes can also be entirely omitted: .. include:: kernel-parameters.txt :literal: - -Todo ----- - - Add more DRM drivers. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 65731b060e3f..31b3a25680d0 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1,3 +1,14 @@ + accept_memory= [MM] + Format: { eager | lazy } + default: lazy + By default, unaccepted memory is accepted lazily to + avoid prolonged boot times. The lazy option will add + some runtime overhead until all memory is eventually + accepted. In most cases the overhead is negligible. + For some workloads or for debugging purposes + accept_memory=eager can be used to accept all memory + at once during boot. + acpi= [HW,ACPI,X86,ARM64,RISCV64] Advanced Configuration and Power Interface Format: { force | on | off | strict | noirq | rsdt | @@ -877,9 +888,9 @@ memory region [offset, offset + size] for that kernel image. If '@offset' is omitted, then a suitable offset is selected automatically. - [KNL, X86-64, ARM64, RISCV] Select a region under 4G first, and - fall back to reserve region above 4G when '@offset' - hasn't been specified. + [KNL, X86-64, ARM64, RISCV, LoongArch] Select a region + under 4G first, and fall back to reserve region above + 4G when '@offset' hasn't been specified. See Documentation/admin-guide/kdump/kdump.rst for further details. crashkernel=range1:size1[,range2:size2,...][@offset] @@ -890,25 +901,27 @@ Documentation/admin-guide/kdump/kdump.rst for an example. crashkernel=size[KMG],high - [KNL, X86-64, ARM64, RISCV] range could be above 4G. + [KNL, X86-64, ARM64, RISCV, LoongArch] range could be + above 4G. Allow kernel to allocate physical memory region from top, so could be above 4G if system have more than 4G ram installed. Otherwise memory region will be allocated below 4G, if available. It will be ignored if crashkernel=X is specified. crashkernel=size[KMG],low - [KNL, X86-64, ARM64, RISCV] range under 4G. When crashkernel=X,high - is passed, kernel could allocate physical memory region - above 4G, that cause second kernel crash on system - that require some amount of low memory, e.g. swiotlb - requires at least 64M+32K low memory, also enough extra - low memory is needed to make sure DMA buffers for 32-bit - devices won't run out. Kernel would try to allocate + [KNL, X86-64, ARM64, RISCV, LoongArch] range under 4G. + When crashkernel=X,high is passed, kernel could allocate + physical memory region above 4G, that cause second kernel + crash on system that require some amount of low memory, + e.g. swiotlb requires at least 64M+32K low memory, also + enough extra low memory is needed to make sure DMA buffers + for 32-bit devices won't run out. Kernel would try to allocate default size of memory below 4G automatically. The default size is platform dependent. --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB) --> arm64: 128MiB --> riscv: 128MiB + --> loongarch: 128MiB This one lets the user specify own low range under 4G for second kernel instead. 0: to disable low allocation. @@ -970,17 +983,17 @@ buddy allocator. Bigger value increase the probability of catching random memory corruption, but reduce the amount of memory for normal system use. The maximum - possible value is MAX_ORDER/2. Setting this parameter - to 1 or 2 should be enough to identify most random - memory corruption problems caused by bugs in kernel or - driver code when a CPU writes to (or reads from) a - random memory location. Note that there exists a class - of memory corruptions problems caused by buggy H/W or - F/W or by drivers badly programming DMA (basically when - memory is written at bus level and the CPU MMU is - bypassed) which are not detectable by - CONFIG_DEBUG_PAGEALLOC, hence this option will not help - tracking down these problems. + possible value is MAX_PAGE_ORDER/2. Setting this + parameter to 1 or 2 should be enough to identify most + random memory corruption problems caused by bugs in + kernel or driver code when a CPU writes to (or reads + from) a random memory location. Note that there exists + a class of memory corruptions problems caused by buggy + H/W or F/W or by drivers badly programming DMA + (basically when memory is written at bus level and the + CPU MMU is bypassed) which are not detectable by + CONFIG_DEBUG_PAGEALLOC, hence this option will not + help tracking down these problems. debug_pagealloc= [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this parameter @@ -2438,7 +2451,7 @@ between unregistering the boot console and initializing the real console. - keepinitrd [HW,ARM] + keepinitrd [HW,ARM] See retain_initrd. kernelcore= [KNL,X86,IA-64,PPC] Format: nn[KMGTPE] | nn% | "mirror" @@ -3985,9 +3998,9 @@ vulnerability. System may allow data leaks with this option. - no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES] Disable paravirtualized - steal time accounting. steal time is computed, but - won't influence scheduler behaviour + no-steal-acc [X86,PV_OPS,ARM64,PPC/PSERIES,RISCV] Disable + paravirtualized steal time accounting. steal time is + computed, but won't influence scheduler behaviour nosync [HW,M68K] Disables sync negotiation for all devices. @@ -4136,7 +4149,7 @@ [KNL] Minimal page reporting order Format: <integer> Adjust the minimal page reporting order. The page - reporting is disabled when it exceeds MAX_ORDER. + reporting is disabled when it exceeds MAX_PAGE_ORDER. panic= [KNL] Kernel behaviour on panic: delay <timeout> timeout > 0: seconds before rebooting @@ -5302,6 +5315,12 @@ Dump ftrace buffer after reporting RCU CPU stall warning. + rcupdate.rcu_cpu_stall_notifiers= [KNL] + Provide RCU CPU stall notifiers, but see the + warnings in the RCU_CPU_STALL_NOTIFIER Kconfig + option's help text. TL;DR: You almost certainly + do not want rcupdate.rcu_cpu_stall_notifiers. + rcupdate.rcu_cpu_stall_suppress= [KNL] Suppress RCU CPU stall warning messages. @@ -5544,6 +5563,13 @@ print every Nth verbose statement, where N is the value specified. + regulator_ignore_unused + [REGULATOR] + Prevents regulator framework from disabling regulators + that are unused, due no driver claiming them. This may + be useful for debug and development, but should not be + needed on a platform with proper driver support. + relax_domain_level= [KNL, SMP] Set scheduler's default relax_domain_level. See Documentation/admin-guide/cgroup-v1/cpusets.rst. @@ -5580,7 +5606,8 @@ Useful for devices that are detected asynchronously (e.g. USB and MMC devices). - retain_initrd [RAM] Keep initrd memory after extraction + retain_initrd [RAM] Keep initrd memory after extraction. After boot, it will + be accessible via /sys/firmware/initrd. retbleed= [X86] Control mitigation of RETBleed (Arbitrary Speculative Code Execution with Return Instructions) @@ -6908,6 +6935,9 @@ pause after every control message); o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra delay after resetting its port); + p = USB_QUIRK_SHORT_SET_ADDRESS_REQ_TIMEOUT + (Reduce timeout of the SET_ADDRESS + request from 5000 ms to 500 ms); Example: quirks=0781:5580:bk,0a5c:5834:gij usbhid.mousepoll= diff --git a/Documentation/admin-guide/kernel-per-CPU-kthreads.rst b/Documentation/admin-guide/kernel-per-CPU-kthreads.rst index 993c2a05f5ee..b6aeae3327ce 100644 --- a/Documentation/admin-guide/kernel-per-CPU-kthreads.rst +++ b/Documentation/admin-guide/kernel-per-CPU-kthreads.rst @@ -243,13 +243,9 @@ To reduce its OS jitter, do any of the following: 3. Do any of the following needed to avoid jitter that your application cannot tolerate: - a. Build your kernel with CONFIG_SLUB=y rather than - CONFIG_SLAB=y, thus avoiding the slab allocator's periodic - use of each CPU's workqueues to run its cache_reap() - function. - b. Avoid using oprofile, thus avoiding OS jitter from + a. Avoid using oprofile, thus avoiding OS jitter from wq_sync_buffer(). - c. Limit your CPU frequency so that a CPU-frequency + b. Limit your CPU frequency so that a CPU-frequency governor is not required, possibly enlisting the aid of special heatsinks or other cooling technologies. If done correctly, and if you CPU architecture permits, you should @@ -259,7 +255,7 @@ To reduce its OS jitter, do any of the following: WARNING: Please check your CPU specifications to make sure that this is safe on your particular system. - d. As of v3.18, Christoph Lameter's on-demand vmstat workers + c. As of v3.18, Christoph Lameter's on-demand vmstat workers commit prevents OS jitter due to vmstat_update() on CONFIG_SMP=y systems. Before v3.18, is not possible to entirely get rid of the OS jitter, but you can @@ -274,7 +270,7 @@ To reduce its OS jitter, do any of the following: (based on an earlier one from Gilad Ben-Yossef) that reduces or even eliminates vmstat overhead for some workloads at https://lore.kernel.org/r/00000140e9dfd6bd-40db3d4f-c1be-434f-8132-7820f81bb586-000000@email.amazonses.com. - e. If running on high-end powerpc servers, build with + d. If running on high-end powerpc servers, build with CONFIG_PPC_RTAS_DAEMON=n. This prevents the RTAS daemon from running on each CPU every second or so. (This will require editing Kconfig files and will defeat @@ -282,12 +278,12 @@ To reduce its OS jitter, do any of the following: due to the rtas_event_scan() function. WARNING: Please check your CPU specifications to make sure that this is safe on your particular system. - f. If running on Cell Processor, build your kernel with + e. If running on Cell Processor, build your kernel with CBE_CPUFREQ_SPU_GOVERNOR=n to avoid OS jitter from spu_gov_work(). WARNING: Please check your CPU specifications to make sure that this is safe on your particular system. - g. If running on PowerMAC, build your kernel with + f. If running on PowerMAC, build your kernel with CONFIG_PMAC_RACKMETER=n to disable the CPU-meter, avoiding OS jitter from rackmeter_do_timer(). diff --git a/Documentation/admin-guide/media/index.rst b/Documentation/admin-guide/media/index.rst index 43f4a292b245..be7e0e4482ca 100644 --- a/Documentation/admin-guide/media/index.rst +++ b/Documentation/admin-guide/media/index.rst @@ -20,16 +20,8 @@ Documentation/driver-api/media/index.rst - for driver development information and Kernel APIs used by media devices; -The media subsystem -=================== - -.. only:: html - - .. class:: toc-title - - Table of Contents - .. toctree:: + :caption: Table of Contents :maxdepth: 2 :numbered: diff --git a/Documentation/admin-guide/media/starfive_camss.rst b/Documentation/admin-guide/media/starfive_camss.rst new file mode 100644 index 000000000000..ca42e9447c47 --- /dev/null +++ b/Documentation/admin-guide/media/starfive_camss.rst @@ -0,0 +1,72 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. include:: <isonum.txt> + +================================ +Starfive Camera Subsystem driver +================================ + +Introduction +------------ + +This file documents the driver for the Starfive Camera Subsystem found on +Starfive JH7110 SoC. The driver is located under drivers/staging/media/starfive/ +camss. + +The driver implements V4L2, Media controller and v4l2_subdev interfaces. Camera +sensor using V4L2 subdev interface in the kernel is supported. + +The driver has been successfully used on the Gstreamer 1.18.5 with v4l2src +plugin. + + +Starfive Camera Subsystem hardware +---------------------------------- + +The Starfive Camera Subsystem hardware consists of:: + + |\ +---------------+ +-----------+ + +----------+ | \ | | | | + | | | | | | | | + | MIPI |----->| |----->| ISP |----->| | + | | | | | | | | + +----------+ | | | | | Memory | + |MUX| +---------------+ | Interface | + +----------+ | | | | + | | | |---------------------------->| | + | Parallel |----->| | | | + | | | | | | + +----------+ | / | | + |/ +-----------+ + +- MIPI: The MIPI interface, receiving data from a MIPI CSI-2 camera sensor. + +- Parallel: The parallel interface, receiving data from a parallel sensor. + +- ISP: The ISP, processing raw Bayer data from an image sensor and producing + YUV frames. + + +Topology +-------- + +The media controller pipeline graph is as follows: + +.. _starfive_camss_graph: + +.. kernel-figure:: starfive_camss_graph.dot + :alt: starfive_camss_graph.dot + :align: center + +The driver has 2 video devices: + +- capture_raw: The capture device, capturing image data directly from a sensor. +- capture_yuv: The capture device, capturing YUV frame data processed by the + ISP module + +The driver has 3 subdevices: + +- stf_isp: is responsible for all the isp operations, outputs YUV frames. +- cdns_csi2rx: a CSI-2 bridge supporting up to 4 CSI lanes in input, and 4 + different pixel streams in output. +- imx219: an image sensor, image data is sent through MIPI CSI-2. diff --git a/Documentation/admin-guide/media/starfive_camss_graph.dot b/Documentation/admin-guide/media/starfive_camss_graph.dot new file mode 100644 index 000000000000..8eff1f161ac7 --- /dev/null +++ b/Documentation/admin-guide/media/starfive_camss_graph.dot @@ -0,0 +1,12 @@ +digraph board { + rankdir=TB + n00000001 [label="{{<port0> 0} | stf_isp\n/dev/v4l-subdev0 | {<port1> 1}}", shape=Mrecord, style=filled, fillcolor=green] + n00000001:port1 -> n00000008 [style=dashed] + n00000004 [label="capture_raw\n/dev/video0", shape=box, style=filled, fillcolor=yellow] + n00000008 [label="capture_yuv\n/dev/video1", shape=box, style=filled, fillcolor=yellow] + n0000000e [label="{{<port0> 0} | cdns_csi2rx.19800000.csi-bridge\n | {<port1> 1 | <port2> 2 | <port3> 3 | <port4> 4}}", shape=Mrecord, style=filled, fillcolor=green] + n0000000e:port1 -> n00000001:port0 [style=dashed] + n0000000e:port1 -> n00000004 [style=dashed] + n00000018 [label="{{} | imx219 6-0010\n/dev/v4l-subdev1 | {<port0> 0}}", shape=Mrecord, style=filled, fillcolor=green] + n00000018:port0 -> n0000000e:port0 [style=bold] +} diff --git a/Documentation/admin-guide/media/v4l-drivers.rst b/Documentation/admin-guide/media/v4l-drivers.rst index 61283d67ceef..f4bb2605f07e 100644 --- a/Documentation/admin-guide/media/v4l-drivers.rst +++ b/Documentation/admin-guide/media/v4l-drivers.rst @@ -28,6 +28,7 @@ Video4Linux (V4L) driver-specific documentation si470x si4713 si476x + starfive_camss vimc visl vivid diff --git a/Documentation/admin-guide/media/visl.rst b/Documentation/admin-guide/media/visl.rst index 4328c6c72d30..db1ef29438e1 100644 --- a/Documentation/admin-guide/media/visl.rst +++ b/Documentation/admin-guide/media/visl.rst @@ -71,6 +71,7 @@ The following codecs are supported: - VP9 - H.264 - HEVC +- AV1 visl trace events ----------------- @@ -79,6 +80,7 @@ The trace events are defined on a per-codec basis, e.g.: .. code-block:: bash $ ls /sys/kernel/tracing/events/ | grep visl + visl_av1_controls visl_fwht_controls visl_h264_controls visl_hevc_controls diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst index da94feb97ed1..9d23144bf985 100644 --- a/Documentation/admin-guide/mm/damon/usage.rst +++ b/Documentation/admin-guide/mm/damon/usage.rst @@ -59,41 +59,47 @@ Files Hierarchy The files hierarchy of DAMON sysfs interface is shown below. In the below figure, parents-children relations are represented with indentations, each directory is having ``/`` suffix, and files in each directory are separated by -comma (","). :: - - /sys/kernel/mm/damon/admin - │ kdamonds/nr_kdamonds - │ │ 0/state,pid - │ │ │ contexts/nr_contexts - │ │ │ │ 0/avail_operations,operations - │ │ │ │ │ monitoring_attrs/ +comma (","). + +.. parsed-literal:: + + :ref:`/sys/kernel/mm/damon <sysfs_root>`/admin + │ :ref:`kdamonds <sysfs_kdamonds>`/nr_kdamonds + │ │ :ref:`0 <sysfs_kdamond>`/state,pid + │ │ │ :ref:`contexts <sysfs_contexts>`/nr_contexts + │ │ │ │ :ref:`0 <sysfs_context>`/avail_operations,operations + │ │ │ │ │ :ref:`monitoring_attrs <sysfs_monitoring_attrs>`/ │ │ │ │ │ │ intervals/sample_us,aggr_us,update_us │ │ │ │ │ │ nr_regions/min,max - │ │ │ │ │ targets/nr_targets - │ │ │ │ │ │ 0/pid_target - │ │ │ │ │ │ │ regions/nr_regions - │ │ │ │ │ │ │ │ 0/start,end + │ │ │ │ │ :ref:`targets <sysfs_targets>`/nr_targets + │ │ │ │ │ │ :ref:`0 <sysfs_target>`/pid_target + │ │ │ │ │ │ │ :ref:`regions <sysfs_regions>`/nr_regions + │ │ │ │ │ │ │ │ :ref:`0 <sysfs_region>`/start,end │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... - │ │ │ │ │ schemes/nr_schemes - │ │ │ │ │ │ 0/action,apply_interval_us - │ │ │ │ │ │ │ access_pattern/ + │ │ │ │ │ :ref:`schemes <sysfs_schemes>`/nr_schemes + │ │ │ │ │ │ :ref:`0 <sysfs_scheme>`/action,apply_interval_us + │ │ │ │ │ │ │ :ref:`access_pattern <sysfs_access_pattern>`/ │ │ │ │ │ │ │ │ sz/min,max │ │ │ │ │ │ │ │ nr_accesses/min,max │ │ │ │ │ │ │ │ age/min,max - │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms + │ │ │ │ │ │ │ :ref:`quotas <sysfs_quotas>`/ms,bytes,reset_interval_ms │ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil - │ │ │ │ │ │ │ watermarks/metric,interval_us,high,mid,low - │ │ │ │ │ │ │ filters/nr_filters + │ │ │ │ │ │ │ │ :ref:`goals <sysfs_schemes_quota_goals>`/nr_goals + │ │ │ │ │ │ │ │ │ 0/target_value,current_value + │ │ │ │ │ │ │ :ref:`watermarks <sysfs_watermarks>`/metric,interval_us,high,mid,low + │ │ │ │ │ │ │ :ref:`filters <sysfs_filters>`/nr_filters │ │ │ │ │ │ │ │ 0/type,matching,memcg_id - │ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds - │ │ │ │ │ │ │ tried_regions/total_bytes + │ │ │ │ │ │ │ :ref:`stats <sysfs_schemes_stats>`/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds + │ │ │ │ │ │ │ :ref:`tried_regions <sysfs_schemes_tried_regions>`/total_bytes │ │ │ │ │ │ │ │ 0/start,end,nr_accesses,age │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... +.. _sysfs_root: + Root ---- @@ -102,6 +108,8 @@ has one directory named ``admin``. The directory contains the files for privileged user space programs' control of DAMON. User space tools or daemons having the root permission could use this directory. +.. _sysfs_kdamonds: + kdamonds/ --------- @@ -113,6 +121,8 @@ details) exists. In the beginning, this directory has only one file, child directories named ``0`` to ``N-1``. Each directory represents each kdamond. +.. _sysfs_kdamond: + kdamonds/<N>/ ------------- @@ -120,29 +130,37 @@ In each kdamond directory, two files (``state`` and ``pid``) and one directory (``contexts``) exist. Reading ``state`` returns ``on`` if the kdamond is currently running, or -``off`` if it is not running. Writing ``on`` or ``off`` makes the kdamond be -in the state. Writing ``commit`` to the ``state`` file makes kdamond reads the -user inputs in the sysfs files except ``state`` file again. Writing -``update_schemes_stats`` to ``state`` file updates the contents of stats files -for each DAMON-based operation scheme of the kdamond. For details of the -stats, please refer to :ref:`stats section <sysfs_schemes_stats>`. - -Writing ``update_schemes_tried_regions`` to ``state`` file updates the -DAMON-based operation scheme action tried regions directory for each -DAMON-based operation scheme of the kdamond. Writing -``update_schemes_tried_bytes`` to ``state`` file updates only -``.../tried_regions/total_bytes`` files. Writing -``clear_schemes_tried_regions`` to ``state`` file clears the DAMON-based -operating scheme action tried regions directory for each DAMON-based operation -scheme of the kdamond. For details of the DAMON-based operation scheme action -tried regions directory, please refer to :ref:`tried_regions section -<sysfs_schemes_tried_regions>`. +``off`` if it is not running. + +Users can write below commands for the kdamond to the ``state`` file. + +- ``on``: Start running. +- ``off``: Stop running. +- ``commit``: Read the user inputs in the sysfs files except ``state`` file + again. +- ``commit_schemes_quota_goals``: Read the DAMON-based operation schemes' + :ref:`quota goals <sysfs_schemes_quota_goals>`. +- ``update_schemes_stats``: Update the contents of stats files for each + DAMON-based operation scheme of the kdamond. For details of the stats, + please refer to :ref:`stats section <sysfs_schemes_stats>`. +- ``update_schemes_tried_regions``: Update the DAMON-based operation scheme + action tried regions directory for each DAMON-based operation scheme of the + kdamond. For details of the DAMON-based operation scheme action tried + regions directory, please refer to + :ref:`tried_regions section <sysfs_schemes_tried_regions>`. +- ``update_schemes_tried_bytes``: Update only ``.../tried_regions/total_bytes`` + files. +- ``clear_schemes_tried_regions``: Clear the DAMON-based operating scheme + action tried regions directory for each DAMON-based operation scheme of the + kdamond. If the state is ``on``, reading ``pid`` shows the pid of the kdamond thread. ``contexts`` directory contains files for controlling the monitoring contexts that this kdamond will execute. +.. _sysfs_contexts: + kdamonds/<N>/contexts/ ---------------------- @@ -153,7 +171,7 @@ number (``N``) to the file creates the number of child directories named as details). At the moment, only one context per kdamond is supported, so only ``0`` or ``1`` can be written to the file. -.. _sysfs_contexts: +.. _sysfs_context: contexts/<N>/ ------------- @@ -203,6 +221,8 @@ writing to and rading from the files. For more details about the intervals and monitoring regions range, please refer to the Design document (:doc:`/mm/damon/design`). +.. _sysfs_targets: + contexts/<N>/targets/ --------------------- @@ -210,6 +230,8 @@ In the beginning, this directory has only one file, ``nr_targets``. Writing a number (``N``) to the file creates the number of child directories named ``0`` to ``N-1``. Each directory represents each monitoring target. +.. _sysfs_target: + targets/<N>/ ------------ @@ -244,6 +266,8 @@ In the beginning, this directory has only one file, ``nr_regions``. Writing a number (``N``) to the file creates the number of child directories named ``0`` to ``N-1``. Each directory represents each initial monitoring target region. +.. _sysfs_region: + regions/<N>/ ------------ @@ -254,6 +278,8 @@ region by writing to and reading from the files, respectively. Each region should not overlap with others. ``end`` of directory ``N`` should be equal or smaller than ``start`` of directory ``N+1``. +.. _sysfs_schemes: + contexts/<N>/schemes/ --------------------- @@ -265,6 +291,8 @@ In the beginning, this directory has only one file, ``nr_schemes``. Writing a number (``N``) to the file creates the number of child directories named ``0`` to ``N-1``. Each directory represents each DAMON-based operation scheme. +.. _sysfs_scheme: + schemes/<N>/ ------------ @@ -277,7 +305,7 @@ The ``action`` file is for setting and getting the scheme's :ref:`action from the file and their meaning are as below. Note that support of each action depends on the running DAMON operations set -:ref:`implementation <sysfs_contexts>`. +:ref:`implementation <sysfs_context>`. - ``willneed``: Call ``madvise()`` for the region with ``MADV_WILLNEED``. Supported by ``vaddr`` and ``fvaddr`` operations set. @@ -299,6 +327,8 @@ Note that support of each action depends on the running DAMON operations set The ``apply_interval_us`` file is for setting and getting the scheme's :ref:`apply_interval <damon_design_damos>` in microseconds. +.. _sysfs_access_pattern: + schemes/<N>/access_pattern/ --------------------------- @@ -312,6 +342,8 @@ to and reading from the ``min`` and ``max`` files under ``sz``, ``nr_accesses``, and ``age`` directories, respectively. Note that the ``min`` and the ``max`` form a closed interval. +.. _sysfs_quotas: + schemes/<N>/quotas/ ------------------- @@ -319,8 +351,7 @@ The directory for the :ref:`quotas <damon_design_damos_quotas>` of the given DAMON-based operation scheme. Under ``quotas`` directory, three files (``ms``, ``bytes``, -``reset_interval_ms``) and one directory (``weights``) having three files -(``sz_permil``, ``nr_accesses_permil``, and ``age_permil``) in it exist. +``reset_interval_ms``) and two directores (``weights`` and ``goals``) exist. You can set the ``time quota`` in milliseconds, ``size quota`` in bytes, and ``reset interval`` in milliseconds by writing the values to the three files, @@ -330,11 +361,37 @@ apply the action to only up to ``bytes`` bytes of memory regions within the ``reset_interval_ms``. Setting both ``ms`` and ``bytes`` zero disables the quota limits. -You can also set the :ref:`prioritization weights +Under ``weights`` directory, three files (``sz_permil``, +``nr_accesses_permil``, and ``age_permil``) exist. +You can set the :ref:`prioritization weights <damon_design_damos_quotas_prioritization>` for size, access frequency, and age in per-thousand unit by writing the values to the three files under the ``weights`` directory. +.. _sysfs_schemes_quota_goals: + +schemes/<N>/quotas/goals/ +------------------------- + +The directory for the :ref:`automatic quota tuning goals +<damon_design_damos_quotas_auto_tuning>` of the given DAMON-based operation +scheme. + +In the beginning, this directory has only one file, ``nr_goals``. Writing a +number (``N``) to the file creates the number of child directories named ``0`` +to ``N-1``. Each directory represents each goal and current achievement. +Among the multiple feedback, the best one is used. + +Each goal directory contains two files, namely ``target_value`` and +``current_value``. Users can set and get any number to those files to set the +feedback. User space main workload's latency or throughput, system metrics +like free memory ratio or memory pressure stall time (PSI) could be example +metrics for the values. Note that users should write +``commit_schemes_quota_goals`` to the ``state`` file of the :ref:`kdamond +directory <sysfs_kdamond>` to pass the feedback to DAMON. + +.. _sysfs_watermarks: + schemes/<N>/watermarks/ ----------------------- @@ -354,6 +411,8 @@ as below. The ``interval`` should written in microseconds unit. +.. _sysfs_filters: + schemes/<N>/filters/ -------------------- @@ -394,7 +453,7 @@ pages of all memory cgroups except ``/having_care_already``.:: echo N > 1/matching Note that ``anon`` and ``memcg`` filters are currently supported only when -``paddr`` :ref:`implementation <sysfs_contexts>` is being used. +``paddr`` :ref:`implementation <sysfs_context>` is being used. Also, memory regions that are filtered out by ``addr`` or ``target`` filters are not counted as the scheme has tried to those, while regions that filtered @@ -449,6 +508,8 @@ and query-like efficient data access monitoring results retrievals. For the latter use case, in particular, users can set the ``action`` as ``stat`` and set the ``access pattern`` as their interested pattern that they want to query. +.. _sysfs_schemes_tried_region: + tried_regions/<N>/ ------------------ diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst index e59231ac6bb7..a639cac12477 100644 --- a/Documentation/admin-guide/mm/ksm.rst +++ b/Documentation/admin-guide/mm/ksm.rst @@ -80,6 +80,9 @@ pages_to_scan how many pages to scan before ksmd goes to sleep e.g. ``echo 100 > /sys/kernel/mm/ksm/pages_to_scan``. + The pages_to_scan value cannot be changed if ``advisor_mode`` has + been set to scan-time. + Default: 100 (chosen for demonstration purposes) sleep_millisecs @@ -164,6 +167,29 @@ smart_scan optimization is enabled. The ``pages_skipped`` metric shows how effective the setting is. +advisor_mode + The ``advisor_mode`` selects the current advisor. Two modes are + supported: none and scan-time. The default is none. By setting + ``advisor_mode`` to scan-time, the scan time advisor is enabled. + The section about ``advisor`` explains in detail how the scan time + advisor works. + +adivsor_max_cpu + specifies the upper limit of the cpu percent usage of the ksmd + background thread. The default is 70. + +advisor_target_scan_time + specifies the target scan time in seconds to scan all the candidate + pages. The default value is 200 seconds. + +advisor_min_pages_to_scan + specifies the lower limit of the ``pages_to_scan`` parameter of the + scan time advisor. The default is 500. + +adivsor_max_pages_to_scan + specifies the upper limit of the ``pages_to_scan`` parameter of the + scan time advisor. The default is 30000. + The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``: general_profit @@ -263,6 +289,35 @@ ksm_swpin_copy note that KSM page might be copied when swapping in because do_swap_page() cannot do all the locking needed to reconstitute a cross-anon_vma KSM page. +Advisor +======= + +The number of candidate pages for KSM is dynamic. It can be often observed +that during the startup of an application more candidate pages need to be +processed. Without an advisor the ``pages_to_scan`` parameter needs to be +sized for the maximum number of candidate pages. The scan time advisor can +changes the ``pages_to_scan`` parameter based on demand. + +The advisor can be enabled, so KSM can automatically adapt to changes in the +number of candidate pages to scan. Two advisors are implemented: none and +scan-time. With none, no advisor is enabled. The default is none. + +The scan time advisor changes the ``pages_to_scan`` parameter based on the +observed scan times. The possible values for the ``pages_to_scan`` parameter is +limited by the ``advisor_max_cpu`` parameter. In addition there is also the +``advisor_target_scan_time`` parameter. This parameter sets the target time to +scan all the KSM candidate pages. The parameter ``advisor_target_scan_time`` +decides how aggressive the scan time advisor scans candidate pages. Lower +values make the scan time advisor to scan more aggresively. This is the most +important parameter for the configuration of the scan time advisor. + +The initial value and the maximum value can be changed with +``advisor_min_pages_to_scan`` and ``advisor_max_pages_to_scan``. The default +values are sufficient for most workloads and use cases. + +The ``pages_to_scan`` parameter is re-calculated after a scan has been completed. + + -- Izik Eidus, Hugh Dickins, 17 Nov 2009 diff --git a/Documentation/admin-guide/mm/pagemap.rst b/Documentation/admin-guide/mm/pagemap.rst index fe17cf210426..f5f065c67615 100644 --- a/Documentation/admin-guide/mm/pagemap.rst +++ b/Documentation/admin-guide/mm/pagemap.rst @@ -253,6 +253,7 @@ Following flags about pages are currently supported: - ``PAGE_IS_SWAPPED`` - Page is in swapped - ``PAGE_IS_PFNZERO`` - Page has zero PFN - ``PAGE_IS_HUGE`` - Page is THP or Hugetlb backed +- ``PAGE_IS_SOFT_DIRTY`` - Page is soft-dirty The ``struct pm_scan_arg`` is used as the argument of the IOCTL. diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index b0cc8243e093..04eb45a2f940 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -45,10 +45,25 @@ components: the two is using hugepages just because of the fact the TLB miss is going to run faster. +Modern kernels support "multi-size THP" (mTHP), which introduces the +ability to allocate memory in blocks that are bigger than a base page +but smaller than traditional PMD-size (as described above), in +increments of a power-of-2 number of pages. mTHP can back anonymous +memory (for example 16K, 32K, 64K, etc). These THPs continue to be +PTE-mapped, but in many cases can still provide similar benefits to +those outlined above: Page faults are significantly reduced (by a +factor of e.g. 4, 8, 16, etc), but latency spikes are much less +prominent because the size of each page isn't as huge as the PMD-sized +variant and there is less memory to clear in each page fault. Some +architectures also employ TLB compression mechanisms to squeeze more +entries in when a set of PTEs are virtually and physically contiguous +and approporiately aligned. In this case, TLB misses will occur less +often. + THP can be enabled system wide or restricted to certain tasks or even memory ranges inside task's address space. Unless THP is completely disabled, there is ``khugepaged`` daemon that scans memory and -collapses sequences of basic pages into huge pages. +collapses sequences of basic pages into PMD-sized huge pages. The THP behaviour is controlled via :ref:`sysfs <thp_sysfs>` interface and using madvise(2) and prctl(2) system calls. @@ -95,12 +110,40 @@ Global THP controls Transparent Hugepage Support for anonymous memory can be entirely disabled (mostly for debugging purposes) or only enabled inside MADV_HUGEPAGE regions (to avoid the risk of consuming more memory resources) or enabled -system wide. This can be achieved with one of:: +system wide. This can be achieved per-supported-THP-size with one of:: + + echo always >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled + echo madvise >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled + echo never >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled + +where <size> is the hugepage size being addressed, the available sizes +for which vary by system. + +For example:: + + echo always >/sys/kernel/mm/transparent_hugepage/hugepages-2048kB/enabled + +Alternatively it is possible to specify that a given hugepage size +will inherit the top-level "enabled" value:: + + echo inherit >/sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/enabled + +For example:: + + echo inherit >/sys/kernel/mm/transparent_hugepage/hugepages-2048kB/enabled + +The top-level setting (for use with "inherit") can be set by issuing +one of the following commands:: echo always >/sys/kernel/mm/transparent_hugepage/enabled echo madvise >/sys/kernel/mm/transparent_hugepage/enabled echo never >/sys/kernel/mm/transparent_hugepage/enabled +By default, PMD-sized hugepages have enabled="inherit" and all other +hugepage sizes have enabled="never". If enabling multiple hugepage +sizes, the kernel will select the most appropriate enabled size for a +given allocation. + It's also possible to limit defrag efforts in the VM to generate anonymous hugepages in case they're not immediately free to madvise regions or to never try to defrag memory and simply fallback to regular @@ -146,25 +189,34 @@ madvise never should be self-explanatory. -By default kernel tries to use huge zero page on read page fault to -anonymous mapping. It's possible to disable huge zero page by writing 0 -or enable it back by writing 1:: +By default kernel tries to use huge, PMD-mappable zero page on read +page fault to anonymous mapping. It's possible to disable huge zero +page by writing 0 or enable it back by writing 1:: echo 0 >/sys/kernel/mm/transparent_hugepage/use_zero_page echo 1 >/sys/kernel/mm/transparent_hugepage/use_zero_page -Some userspace (such as a test program, or an optimized memory allocation -library) may want to know the size (in bytes) of a transparent hugepage:: +Some userspace (such as a test program, or an optimized memory +allocation library) may want to know the size (in bytes) of a +PMD-mappable transparent hugepage:: cat /sys/kernel/mm/transparent_hugepage/hpage_pmd_size -khugepaged will be automatically started when -transparent_hugepage/enabled is set to "always" or "madvise, and it'll -be automatically shutdown if it's set to "never". +khugepaged will be automatically started when one or more hugepage +sizes are enabled (either by directly setting "always" or "madvise", +or by setting "inherit" while the top-level enabled is set to "always" +or "madvise"), and it'll be automatically shutdown when the last +hugepage size is disabled (either by directly setting "never", or by +setting "inherit" while the top-level enabled is set to "never"). Khugepaged controls ------------------- +.. note:: + khugepaged currently only searches for opportunities to collapse to + PMD-sized THP and no attempt is made to collapse to other THP + sizes. + khugepaged runs usually at low frequency so while one may not want to invoke defrag algorithms synchronously during the page faults, it should be worth invoking defrag at least in khugepaged. However it's @@ -282,19 +334,26 @@ force Need of application restart =========================== -The transparent_hugepage/enabled values and tmpfs mount option only affect -future behavior. So to make them effective you need to restart any -application that could have been using hugepages. This also applies to the -regions registered in khugepaged. +The transparent_hugepage/enabled and +transparent_hugepage/hugepages-<size>kB/enabled values and tmpfs mount +option only affect future behavior. So to make them effective you need +to restart any application that could have been using hugepages. This +also applies to the regions registered in khugepaged. Monitoring usage ================ -The number of anonymous transparent huge pages currently used by the +.. note:: + Currently the below counters only record events relating to + PMD-sized THP. Events relating to other THP sizes are not included. + +The number of PMD-sized anonymous transparent huge pages currently used by the system is available by reading the AnonHugePages field in ``/proc/meminfo``. -To identify what applications are using anonymous transparent huge pages, -it is necessary to read ``/proc/PID/smaps`` and count the AnonHugePages fields -for each mapping. +To identify what applications are using PMD-sized anonymous transparent huge +pages, it is necessary to read ``/proc/PID/smaps`` and count the AnonHugePages +fields for each mapping. (Note that AnonHugePages only applies to traditional +PMD-sized THP for historical reasons and should have been called +AnonHugePmdMapped). The number of file transparent huge pages mapped to userspace is available by reading ShmemPmdMapped and ShmemHugePages fields in ``/proc/meminfo``. @@ -413,7 +472,7 @@ for huge pages. Optimizing the applications =========================== -To be guaranteed that the kernel will map a 2M page immediately in any +To be guaranteed that the kernel will map a THP immediately in any memory region, the mmap region has to be hugepage naturally aligned. posix_memalign() can provide that guarantee. diff --git a/Documentation/admin-guide/mm/userfaultfd.rst b/Documentation/admin-guide/mm/userfaultfd.rst index 203e26da5f92..e5cc8848dcb3 100644 --- a/Documentation/admin-guide/mm/userfaultfd.rst +++ b/Documentation/admin-guide/mm/userfaultfd.rst @@ -113,6 +113,9 @@ events, except page fault notifications, may be generated: areas. ``UFFD_FEATURE_MINOR_SHMEM`` is the analogous feature indicating support for shmem virtual memory areas. +- ``UFFD_FEATURE_MOVE`` indicates that the kernel supports moving an + existing page contents from userspace. + The userland application should set the feature flags it intends to use when invoking the ``UFFDIO_API`` ioctl, to request that those features be enabled if supported. diff --git a/Documentation/admin-guide/mm/zswap.rst b/Documentation/admin-guide/mm/zswap.rst index 45b98390e938..b42132969e31 100644 --- a/Documentation/admin-guide/mm/zswap.rst +++ b/Documentation/admin-guide/mm/zswap.rst @@ -153,6 +153,26 @@ attribute, e. g.:: Setting this parameter to 100 will disable the hysteresis. +Some users cannot tolerate the swapping that comes with zswap store failures +and zswap writebacks. Swapping can be disabled entirely (without disabling +zswap itself) on a cgroup-basis as follows: + + echo 0 > /sys/fs/cgroup/<cgroup-name>/memory.zswap.writeback + +Note that if the store failures are recurring (for e.g if the pages are +incompressible), users can observe reclaim inefficiency after disabling +writeback (because the same pages might be rejected again and again). + +When there is a sizable amount of cold memory residing in the zswap pool, it +can be advantageous to proactively write these cold pages to swap and reclaim +the memory for other use cases. By default, the zswap shrinker is disabled. +User can enable it as follows: + + echo Y > /sys/module/zswap/parameters/shrinker_enabled + +This can be enabled at the boot time if ``CONFIG_ZSWAP_SHRINKER_DEFAULT_ON`` is +selected. + A debugfs interface is provided for various statistic about pool size, number of pages stored, same-value filled pages and various counters for the reasons pages are rejected. diff --git a/Documentation/admin-guide/perf/dwc_pcie_pmu.rst b/Documentation/admin-guide/perf/dwc_pcie_pmu.rst new file mode 100644 index 000000000000..d47cd229d710 --- /dev/null +++ b/Documentation/admin-guide/perf/dwc_pcie_pmu.rst @@ -0,0 +1,94 @@ +====================================================================== +Synopsys DesignWare Cores (DWC) PCIe Performance Monitoring Unit (PMU) +====================================================================== + +DesignWare Cores (DWC) PCIe PMU +=============================== + +The PMU is a PCIe configuration space register block provided by each PCIe Root +Port in a Vendor-Specific Extended Capability named RAS D.E.S (Debug, Error +injection, and Statistics). + +As the name indicates, the RAS DES capability supports system level +debugging, AER error injection, and collection of statistics. To facilitate +collection of statistics, Synopsys DesignWare Cores PCIe controller +provides the following two features: + +- one 64-bit counter for Time Based Analysis (RX/TX data throughput and + time spent in each low-power LTSSM state) and +- one 32-bit counter for Event Counting (error and non-error events for + a specified lane) + +Note: There is no interrupt for counter overflow. + +Time Based Analysis +------------------- + +Using this feature you can obtain information regarding RX/TX data +throughput and time spent in each low-power LTSSM state by the controller. +The PMU measures data in two categories: + +- Group#0: Percentage of time the controller stays in LTSSM states. +- Group#1: Amount of data processed (Units of 16 bytes). + +Lane Event counters +------------------- + +Using this feature you can obtain Error and Non-Error information in +specific lane by the controller. The PMU event is selected by all of: + +- Group i +- Event j within the Group i +- Lane k + +Some of the events only exist for specific configurations. + +DesignWare Cores (DWC) PCIe PMU Driver +======================================= + +This driver adds PMU devices for each PCIe Root Port named based on the BDF of +the Root Port. For example, + + 30:03.0 PCI bridge: Device 1ded:8000 (rev 01) + +the PMU device name for this Root Port is dwc_rootport_3018. + +The DWC PCIe PMU driver registers a perf PMU driver, which provides +description of available events and configuration options in sysfs, see +/sys/bus/event_source/devices/dwc_rootport_{bdf}. + +The "format" directory describes format of the config fields of the +perf_event_attr structure. The "events" directory provides configuration +templates for all documented events. For example, +"Rx_PCIe_TLP_Data_Payload" is an equivalent of "eventid=0x22,type=0x1". + +The "perf list" command shall list the available events from sysfs, e.g.:: + + $# perf list | grep dwc_rootport + <...> + dwc_rootport_3018/Rx_PCIe_TLP_Data_Payload/ [Kernel PMU event] + <...> + dwc_rootport_3018/rx_memory_read,lane=?/ [Kernel PMU event] + +Time Based Analysis Event Usage +------------------------------- + +Example usage of counting PCIe RX TLP data payload (Units of bytes):: + + $# perf stat -a -e dwc_rootport_3018/Rx_PCIe_TLP_Data_Payload/ + +The average RX/TX bandwidth can be calculated using the following formula: + + PCIe RX Bandwidth = Rx_PCIe_TLP_Data_Payload / Measure_Time_Window + PCIe TX Bandwidth = Tx_PCIe_TLP_Data_Payload / Measure_Time_Window + +Lane Event Usage +------------------------------- + +Each lane has the same event set and to avoid generating a list of hundreds +of events, the user need to specify the lane ID explicitly, e.g.:: + + $# perf stat -a -e dwc_rootport_3018/rx_memory_read,lane=4/ + +The driver does not support sampling, therefore "perf record" will not +work. Per-task (without "-a") perf sessions are not supported. diff --git a/Documentation/admin-guide/perf/imx-ddr.rst b/Documentation/admin-guide/perf/imx-ddr.rst index 90926d0fb8ec..77418ae5a290 100644 --- a/Documentation/admin-guide/perf/imx-ddr.rst +++ b/Documentation/admin-guide/perf/imx-ddr.rst @@ -13,8 +13,8 @@ is one register for each counter. Counter 0 is special in that it always counts interrupt is raised. If any other counter overflows, it continues counting, and no interrupt is raised. -The "format" directory describes format of the config (event ID) and config1 -(AXI filtering) fields of the perf_event_attr structure, see /sys/bus/event_source/ +The "format" directory describes format of the config (event ID) and config1/2 +(AXI filter setting) fields of the perf_event_attr structure, see /sys/bus/event_source/ devices/imx8_ddr0/format/. The "events" directory describes the events types hardware supported that can be used with perf tool, see /sys/bus/event_source/ devices/imx8_ddr0/events/. The "caps" directory describes filter features implemented @@ -28,12 +28,11 @@ in DDR PMU, see /sys/bus/events_source/devices/imx8_ddr0/caps/. AXI filtering is only used by CSV modes 0x41 (axid-read) and 0x42 (axid-write) to count reading or writing matches filter setting. Filter setting is various from different DRAM controller implementations, which is distinguished by quirks -in the driver. You also can dump info from userspace, filter in "caps" directory -indicates whether PMU supports AXI ID filter or not; enhanced_filter indicates -whether PMU supports enhanced AXI ID filter or not. Value 0 for un-supported, and -value 1 for supported. +in the driver. You also can dump info from userspace, "caps" directory show the +type of AXI filter (filter, enhanced_filter and super_filter). Value 0 for +un-supported, and value 1 for supported. -* With DDR_CAP_AXI_ID_FILTER quirk(filter: 1, enhanced_filter: 0). +* With DDR_CAP_AXI_ID_FILTER quirk(filter: 1, enhanced_filter: 0, super_filter: 0). Filter is defined with two configuration parts: --AXI_ID defines AxID matching value. --AXI_MASKING defines which bits of AxID are meaningful for the matching. @@ -65,7 +64,37 @@ value 1 for supported. perf stat -a -e imx8_ddr0/axid-read,axi_id=0x12/ cmd, which will monitor ARID=0x12 -* With DDR_CAP_AXI_ID_FILTER_ENHANCED quirk(filter: 1, enhanced_filter: 1). +* With DDR_CAP_AXI_ID_FILTER_ENHANCED quirk(filter: 1, enhanced_filter: 1, super_filter: 0). This is an extension to the DDR_CAP_AXI_ID_FILTER quirk which permits counting the number of bytes (as opposed to the number of bursts) from DDR read and write transactions concurrently with another set of data counters. + +* With DDR_CAP_AXI_ID_PORT_CHANNEL_FILTER quirk(filter: 0, enhanced_filter: 0, super_filter: 1). + There is a limitation in previous AXI filter, it cannot filter different IDs + at the same time as the filter is shared between counters. This quirk is the + extension of AXI ID filter. One improvement is that counter 1-3 has their own + filter, means that it supports concurrently filter various IDs. Another + improvement is that counter 1-3 supports AXI PORT and CHANNEL selection. Support + selecting address channel or data channel. + + Filter is defined with 2 configuration registers per counter 1-3. + --Counter N MASK COMP register - including AXI_ID and AXI_MASKING. + --Counter N MUX CNTL register - including AXI CHANNEL and AXI PORT. + + - 0: address channel + - 1: data channel + + PMU in DDR subsystem, only one single port0 exists, so axi_port is reserved + which should be 0. + + .. code-block:: bash + + perf stat -a -e imx8_ddr0/axid-read,axi_mask=0xMMMM,axi_id=0xDDDD,axi_channel=0xH/ cmd + perf stat -a -e imx8_ddr0/axid-write,axi_mask=0xMMMM,axi_id=0xDDDD,axi_channel=0xH/ cmd + + .. note:: + + axi_channel is inverted in userspace, and it will be reverted in driver + automatically. So that users do not need specify axi_channel if want to + monitor data channel from DDR transactions, since data channel is more + meaningful. diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst index a2e6f2c81146..f4a4513c526f 100644 --- a/Documentation/admin-guide/perf/index.rst +++ b/Documentation/admin-guide/perf/index.rst @@ -19,6 +19,7 @@ Performance monitor support arm_dsu_pmu thunderx2-pmu alibaba_pmu + dwc_pcie_pmu nvidia-pmu meson-ddr-pmu cxl diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 1cf40f69278c..9eb26014d34b 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -361,7 +361,7 @@ Global Attributes ``amd-pstate`` exposes several global attributes (files) in ``sysfs`` to control its functionality at the system level. They are located in the -``/sys/devices/system/cpu/amd-pstate/`` directory and affect all CPUs. +``/sys/devices/system/cpu/amd_pstate/`` directory and affect all CPUs. ``status`` Operation mode of the driver: "active", "passive" or "disable". diff --git a/Documentation/admin-guide/pmf.rst b/Documentation/admin-guide/pmf.rst new file mode 100644 index 000000000000..9ee729ffc19b --- /dev/null +++ b/Documentation/admin-guide/pmf.rst @@ -0,0 +1,24 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Set udev rules for PMF Smart PC Builder +--------------------------------------- + +AMD PMF(Platform Management Framework) Smart PC Solution builder has to set the system states +like S0i3, Screen lock, hibernate etc, based on the output actions provided by the PMF +TA (Trusted Application). + +In order for this to work the PMF driver generates a uevent for userspace to react to. Below are +sample udev rules that can facilitate this experience when a machine has PMF Smart PC solution builder +enabled. + +Please add the following line(s) to +``/etc/udev/rules.d/99-local.rules``:: + + DRIVERS=="amd-pmf", ACTION=="change", ENV{EVENT_ID}=="0", RUN+="/usr/bin/systemctl suspend" + DRIVERS=="amd-pmf", ACTION=="change", ENV{EVENT_ID}=="1", RUN+="/usr/bin/systemctl hibernate" + DRIVERS=="amd-pmf", ACTION=="change", ENV{EVENT_ID}=="2", RUN+="/bin/loginctl lock-sessions" + +EVENT_ID values: +0= Put the system to S0i3/S2Idle +1= Put the system to hibernate +2= Lock the screen diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index c7525942f12c..396091651955 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -345,7 +345,10 @@ optmem_max ---------- Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence -of struct cmsghdr structures with appended data. +of struct cmsghdr structures with appended data. TCP tx zerocopy also uses +optmem_max as a limit for its internal structures. + +Default : 128 KB fb_tunnels_only_for_init_net ---------------------------- diff --git a/Documentation/admin-guide/sysrq.rst b/Documentation/admin-guide/sysrq.rst index 51906e47327b..2f2e5bd440f9 100644 --- a/Documentation/admin-guide/sysrq.rst +++ b/Documentation/admin-guide/sysrq.rst @@ -75,10 +75,19 @@ On other submit a patch to be included in this section. On all - Write a character to /proc/sysrq-trigger. e.g.:: + Write a single character to /proc/sysrq-trigger. + Only the first character is processed, the rest of the string is + ignored. However, it is not recommended to write any extra characters + as the behavior is undefined and might change in the future versions. + E.g.:: echo t > /proc/sysrq-trigger + Alternatively, write multiple characters prepended by underscore. + This way, all characters will be processed. E.g.:: + + echo _reisub > /proc/sysrq-trigger + The :kbd:`<command key>` is case sensitive. What are the 'command' keys? |