diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/blockdev/zram.rst | 100 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v1/memory.rst | 3 | ||||
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 6 | ||||
| -rw-r--r-- | Documentation/admin-guide/cifs/usage.rst | 2 | ||||
| -rw-r--r-- | Documentation/admin-guide/kdump/vmcoreinfo.rst | 29 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 51 | ||||
| -rw-r--r-- | Documentation/admin-guide/mm/damon/usage.rst | 59 | ||||
| -rw-r--r-- | Documentation/admin-guide/mm/zswap.rst | 4 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/kernel.rst | 27 |
9 files changed, 255 insertions, 26 deletions
diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index c73b16930449..e4551579cb12 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -348,8 +348,13 @@ this can be accomplished with:: echo huge_idle > /sys/block/zramX/writeback +If a user chooses to writeback only incompressible pages (pages that none of +algorithms can compress) this can be accomplished with:: + + echo incompressible > /sys/block/zramX/writeback + If an admin wants to write a specific page in zram device to the backing device, -they could write a page index into the interface. +they could write a page index into the interface:: echo "page_index=1251" > /sys/block/zramX/writeback @@ -401,6 +406,87 @@ budget in next setting is user's job. If admin wants to measure writeback count in a certain period, they could know it via /sys/block/zram0/bd_stat's 3rd column. +recompression +------------- + +With CONFIG_ZRAM_MULTI_COMP, zram can recompress pages using alternative +(secondary) compression algorithms. The basic idea is that alternative +compression algorithm can provide better compression ratio at a price of +(potentially) slower compression/decompression speeds. Alternative compression +algorithm can, for example, be more successful compressing huge pages (those +that default algorithm failed to compress). Another application is idle pages +recompression - pages that are cold and sit in the memory can be recompressed +using more effective algorithm and, hence, reduce zsmalloc memory usage. + +With CONFIG_ZRAM_MULTI_COMP, zram supports up to 4 compression algorithms: +one primary and up to 3 secondary ones. Primary zram compressor is explained +in "3) Select compression algorithm", secondary algorithms are configured +using recomp_algorithm device attribute. + +Example::: + + #show supported recompression algorithms + cat /sys/block/zramX/recomp_algorithm + #1: lzo lzo-rle lz4 lz4hc [zstd] + #2: lzo lzo-rle lz4 [lz4hc] zstd + +Alternative compression algorithms are sorted by priority. In the example +above, zstd is used as the first alternative algorithm, which has priority +of 1, while lz4hc is configured as a compression algorithm with priority 2. +Alternative compression algorithm's priority is provided during algorithms +configuration::: + + #select zstd recompression algorithm, priority 1 + echo "algo=zstd priority=1" > /sys/block/zramX/recomp_algorithm + + #select deflate recompression algorithm, priority 2 + echo "algo=deflate priority=2" > /sys/block/zramX/recomp_algorithm + +Another device attribute that CONFIG_ZRAM_MULTI_COMP enables is recompress, +which controls recompression. + +Examples::: + + #IDLE pages recompression is activated by `idle` mode + echo "type=idle" > /sys/block/zramX/recompress + + #HUGE pages recompression is activated by `huge` mode + echo "type=huge" > /sys/block/zram0/recompress + + #HUGE_IDLE pages recompression is activated by `huge_idle` mode + echo "type=huge_idle" > /sys/block/zramX/recompress + +The number of idle pages can be significant, so user-space can pass a size +threshold (in bytes) to the recompress knob: zram will recompress only pages +of equal or greater size::: + + #recompress all pages larger than 3000 bytes + echo "threshold=3000" > /sys/block/zramX/recompress + + #recompress idle pages larger than 2000 bytes + echo "type=idle threshold=2000" > /sys/block/zramX/recompress + +Recompression of idle pages requires memory tracking. + +During re-compression for every page, that matches re-compression criteria, +ZRAM iterates the list of registered alternative compression algorithms in +order of their priorities. ZRAM stops either when re-compression was +successful (re-compressed object is smaller in size than the original one) +and matches re-compression criteria (e.g. size threshold) or when there are +no secondary algorithms left to try. If none of the secondary algorithms can +successfully re-compressed the page such a page is marked as incompressible, +so ZRAM will not attempt to re-compress it in the future. + +This re-compression behaviour, when it iterates through the list of +registered compression algorithms, increases our chances of finding the +algorithm that successfully compresses a particular page. Sometimes, however, +it is convenient (and sometimes even necessary) to limit recompression to +only one particular algorithm so that it will not try any other algorithms. +This can be achieved by providing a algo=NAME parameter::: + + #use zstd algorithm only (if registered) + echo "type=huge algo=zstd" > /sys/block/zramX/recompress + memory tracking =============== @@ -411,9 +497,11 @@ pages of the process with*pagemap. If you enable the feature, you could see block state via /sys/kernel/debug/zram/zram0/block_state". The output is as follows:: - 300 75.033841 .wh. - 301 63.806904 s... - 302 63.806919 ..hi + 300 75.033841 .wh... + 301 63.806904 s..... + 302 63.806919 ..hi.. + 303 62.801919 ....r. + 304 146.781902 ..hi.n First column zram's block index. @@ -430,6 +518,10 @@ Third column huge page i: idle page + r: + recompressed page (secondary compression algorithm) + n: + none (including secondary) of algorithms could compress it First line of above example says 300th block is accessed at 75.033841sec and the block's state is huge so it is written back to the backing diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index 5b86245450bd..60370f2c67b9 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -543,7 +543,8 @@ inactive_anon # of bytes of anonymous and swap cache memory on inactive LRU list. active_anon # of bytes of anonymous and swap cache memory on active LRU list. -inactive_file # of bytes of file-backed memory on inactive LRU list. +inactive_file # of bytes of file-backed memory and MADV_FREE anonymous memory( + LazyFree pages) on inactive LRU list. active_file # of bytes of file-backed memory on active LRU list. unevictable # of bytes of memory that cannot be reclaimed (mlocked etc). =============== =============================================================== diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index dc254a3cb956..74cec76be9f2 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1488,12 +1488,18 @@ PAGE_SIZE multiple when read back. pgscan_direct (npn) Amount of scanned pages directly (in an inactive LRU list) + pgscan_khugepaged (npn) + Amount of scanned pages by khugepaged (in an inactive LRU list) + pgsteal_kswapd (npn) Amount of reclaimed pages by kswapd pgsteal_direct (npn) Amount of reclaimed pages directly + pgsteal_khugepaged (npn) + Amount of reclaimed pages by khugepaged + pgfault (npn) Total number of page faults incurred diff --git a/Documentation/admin-guide/cifs/usage.rst b/Documentation/admin-guide/cifs/usage.rst index 3766bf8a1c20..ed3b8dc854ec 100644 --- a/Documentation/admin-guide/cifs/usage.rst +++ b/Documentation/admin-guide/cifs/usage.rst @@ -858,7 +858,7 @@ CIFS kernel module parameters These module parameters can be specified or modified either during the time of module loading or during the runtime by using the interface:: - /proc/module/cifs/parameters/<param> + /sys/module/cifs/parameters/<param> i.e.:: diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 6726f439958c..86fd88492870 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -595,3 +595,32 @@ X2TLB ----- Indicates whether the crashed kernel enabled SH extended mode. + +RISCV64 +======= + +VA_BITS +------- + +The maximum number of bits for virtual addresses. Used to compute the +virtual memory ranges. + +PAGE_OFFSET +----------- + +Indicates the virtual kernel start address of the direct-mapped RAM region. + +phys_ram_base +------------- + +Indicates the start physical RAM address. + +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END|KERNEL_LINK_ADDR +---------------------------------------------------------------------------------------------- + +Used to get the correct ranges: + + * MODULES_VADDR ~ MODULES_END : Kernel module space. + * VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space. + * VMEMMAP_START ~ VMEMMAP_END : vmemmap space, used for struct page array. + * KERNEL_LINK_ADDR : start address of Kernel link and BPF diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb388c6c8c60..6cfa6e3996cf 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1050,6 +1050,11 @@ them frequently to increase the rate of SLB faults on kernel addresses. + stress_hpt [PPC] + Limits the number of kernel HPT entries in the hash + page table to increase the rate of hash page table + faults on kernel addresses. + disable= [IPV6] See Documentation/networking/ipv6.rst. @@ -2308,7 +2313,13 @@ Provide an override to the IOAPIC-ID<->DEVICE-ID mapping provided in the IVRS ACPI table. By default, PCI segment is 0, and can be omitted. - For example: + + For example, to map IOAPIC-ID decimal 10 to + PCI segment 0x1 and PCI device 00:14.0, + write the parameter as: + ivrs_ioapic=10@0001:00:14.0 + + Deprecated formats: * To map IOAPIC-ID decimal 10 to PCI device 00:14.0 write the parameter as: ivrs_ioapic[10]=00:14.0 @@ -2320,7 +2331,13 @@ Provide an override to the HPET-ID<->DEVICE-ID mapping provided in the IVRS ACPI table. By default, PCI segment is 0, and can be omitted. - For example: + + For example, to map HPET-ID decimal 10 to + PCI segment 0x1 and PCI device 00:14.0, + write the parameter as: + ivrs_hpet=10@0001:00:14.0 + + Deprecated formats: * To map HPET-ID decimal 0 to PCI device 00:14.0 write the parameter as: ivrs_hpet[0]=00:14.0 @@ -2331,15 +2348,20 @@ ivrs_acpihid [HW,X86-64] Provide an override to the ACPI-HID:UID<->DEVICE-ID mapping provided in the IVRS ACPI table. + By default, PCI segment is 0, and can be omitted. For example, to map UART-HID:UID AMD0020:0 to PCI segment 0x1 and PCI device ID 00:14.5, write the parameter as: - ivrs_acpihid[0001:00:14.5]=AMD0020:0 + ivrs_acpihid=AMD0020:0@0001:00:14.5 - By default, PCI segment is 0, and can be omitted. - For example, PCI device 00:14.5 write the parameter as: + Deprecated formats: + * To map UART-HID:UID AMD0020:0 to PCI segment is 0, + PCI device ID 00:14.5, write the parameter as: ivrs_acpihid[00:14.5]=AMD0020:0 + * To map UART-HID:UID AMD0020:0 to PCI segment 0x1 and + PCI device ID 00:14.5, write the parameter as: + ivrs_acpihid[0001:00:14.5]=AMD0020:0 js= [HW,JOY] Analog joystick See Documentation/input/joydev/joystick.rst. @@ -6266,6 +6288,25 @@ See also Documentation/trace/ftrace.rst "trace options" section. + trace_trigger=[trigger-list] + [FTRACE] Add a event trigger on specific events. + Set a trigger on top of a specific event, with an optional + filter. + + The format is is "trace_trigger=<event>.<trigger>[ if <filter>],..." + Where more than one trigger may be specified that are comma deliminated. + + For example: + + trace_trigger="sched_switch.stacktrace if prev_state == 2" + + The above will enable the "stacktrace" trigger on the "sched_switch" + event but only trigger it if the "prev_state" of the "sched_switch" + event is "2" (TASK_UNINTERUPTIBLE). + + See also "Event triggers" in Documentation/trace/events.rst + + traceoff_on_warning [FTRACE] enable this option to disable tracing when a warning is hit. This turns off "tracing_on". Tracing can diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst index b47b0cbbd491..1a5b6b71efa1 100644 --- a/Documentation/admin-guide/mm/damon/usage.rst +++ b/Documentation/admin-guide/mm/damon/usage.rst @@ -88,6 +88,9 @@ comma (","). :: │ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil │ │ │ │ │ │ │ watermarks/metric,interval_us,high,mid,low │ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds + │ │ │ │ │ │ │ tried_regions/ + │ │ │ │ │ │ │ │ 0/start,end,nr_accesses,age + │ │ │ │ │ │ │ │ ... │ │ │ │ │ │ ... │ │ │ │ ... │ │ ... @@ -125,7 +128,14 @@ 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>`. +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 ``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>`. If the state is ``on``, reading ``pid`` shows the pid of the kdamond thread. @@ -166,6 +176,8 @@ You can set and get what type of monitoring operations DAMON will use for the context by writing one of the keywords listed in ``avail_operations`` file and reading from the ``operations`` file. +.. _sysfs_monitoring_attrs: + contexts/<N>/monitoring_attrs/ ------------------------------ @@ -235,6 +247,9 @@ In each region directory, you will find two files (``start`` and ``end``). You can set and get the start and end addresses of the initial monitoring target 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``. + contexts/<N>/schemes/ --------------------- @@ -252,8 +267,9 @@ to ``N-1``. Each directory represents each DAMON-based operation scheme. schemes/<N>/ ------------ -In each scheme directory, four directories (``access_pattern``, ``quotas``, -``watermarks``, and ``stats``) and one file (``action``) exist. +In each scheme directory, five directories (``access_pattern``, ``quotas``, +``watermarks``, ``stats``, and ``tried_regions``) and one file (``action``) +exist. The ``action`` file is for setting and getting what action you want to apply to memory regions having specific access pattern of the interest. The keywords @@ -348,6 +364,32 @@ should ask DAMON sysfs interface to updte the content of the files for the stats by writing a special keyword, ``update_schemes_stats`` to the relevant ``kdamonds/<N>/state`` file. +.. _sysfs_schemes_tried_regions: + +schemes/<N>/tried_regions/ +-------------------------- + +When a special keyword, ``update_schemes_tried_regions``, is written to the +relevant ``kdamonds/<N>/state`` file, DAMON creates directories named integer +starting from ``0`` under this directory. Each directory contains files +exposing detailed information about each of the memory region that the +corresponding scheme's ``action`` has tried to be applied under this directory, +during next :ref:`aggregation interval <sysfs_monitoring_attrs>`. The +information includes address range, ``nr_accesses``, , and ``age`` of the +region. + +The directories will be removed when another special keyword, +``clear_schemes_tried_regions``, is written to the relevant +``kdamonds/<N>/state`` file. + +tried_regions/<N>/ +------------------ + +In each region directory, you will find four files (``start``, ``end``, +``nr_accesses``, and ``age``). Reading the files will show the start and end +addresses, ``nr_accesses``, and ``age`` of the region that corresponding +DAMON-based operation scheme ``action`` has tried to be applied. + Example ~~~~~~~ @@ -465,8 +507,9 @@ regions in case of physical memory monitoring. Therefore, users should set the monitoring target regions by themselves. In such cases, users can explicitly set the initial monitoring target regions -as they want, by writing proper values to the ``init_regions`` file. Each line -of the input should represent one region in below form.:: +as they want, by writing proper values to the ``init_regions`` file. The input +should be a sequence of three integers separated by white spaces that represent +one region in below form.:: <target idx> <start address> <end address> @@ -481,9 +524,9 @@ ranges, ``20-40`` and ``50-100`` as that of pid 4242, which is the second one # cd <debugfs>/damon # cat target_ids 42 4242 - # echo "0 1 100 - 0 100 200 - 1 20 40 + # echo "0 1 100 \ + 0 100 200 \ + 1 20 40 \ 1 50 100" > init_regions Note that this sets the initial monitoring target regions only. In case of diff --git a/Documentation/admin-guide/mm/zswap.rst b/Documentation/admin-guide/mm/zswap.rst index f67de481c7f6..6dd74a18268b 100644 --- a/Documentation/admin-guide/mm/zswap.rst +++ b/Documentation/admin-guide/mm/zswap.rst @@ -70,9 +70,7 @@ e.g. ``zswap.zpool=zbud``. It can also be changed at runtime using the sysfs The zbud type zpool allocates exactly 1 page to store 2 compressed pages, which means the compression ratio will always be 2:1 or worse (because of half-full zbud pages). The zsmalloc type zpool has a more complex compressed page -storage method, and it can achieve greater storage densities. However, -zsmalloc does not implement compressed page eviction, so once zswap fills it -cannot evict the oldest page, it can only reject new pages. +storage method, and it can achieve greater storage densities. When a swap page is passed from frontswap to zswap, zswap maintains a mapping of the swap entry, a combination of the swap type and swap offset, to the zpool diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 39e7a2d46e1e..46e3d62c0eea 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -436,8 +436,8 @@ ignore-unaligned-usertrap On architectures where unaligned accesses cause traps, and where this feature is supported (``CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN``; -currently, ``arc`` and ``ia64``), controls whether all unaligned traps -are logged. +currently, ``arc``, ``ia64`` and ``loongarch``), controls whether all +unaligned traps are logged. = ============================================================= 0 Log all unaligned accesses. @@ -670,6 +670,15 @@ This is the default behavior. an oops event is detected. +oops_limit +========== + +Number of kernel oopses after which the kernel should panic when +``panic_on_oops`` is not set. Setting this to 0 disables checking +the count. Setting this to 1 has the same effect as setting +``panic_on_oops=1``. The default value is 10000. + + osrelease, ostype & version =========================== @@ -1483,8 +1492,8 @@ unaligned-trap On architectures where unaligned accesses cause traps, and where this feature is supported (``CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW``; currently, -``arc`` and ``parisc``), controls whether unaligned traps are caught -and emulated (instead of failing). +``arc``, ``parisc`` and ``loongarch``), controls whether unaligned traps +are caught and emulated (instead of failing). = ======================================================== 0 Do not emulate unaligned accesses. @@ -1526,6 +1535,16 @@ entry will default to 2 instead of 0. 2 Unprivileged calls to ``bpf()`` are disabled = ============================================================= + +warn_limit +========== + +Number of kernel warnings after which the kernel should panic when +``panic_on_warn`` is not set. Setting this to 0 disables checking +the warning count. Setting this to 1 has the same effect as setting +``panic_on_warn=1``. The default value is 0. + + watchdog ======== |