diff options
Diffstat (limited to 'Documentation/admin-guide')
55 files changed, 1969 insertions, 560 deletions
diff --git a/Documentation/admin-guide/README.rst b/Documentation/admin-guide/README.rst index 95a28f47ac30..261b7b4cca1f 100644 --- a/Documentation/admin-guide/README.rst +++ b/Documentation/admin-guide/README.rst @@ -398,8 +398,8 @@ If something goes wrong If you for some reason cannot do the above (you have a pre-compiled kernel image or similar), telling me as much about your setup as - possible will help. Please read the :ref:`admin-guide/reporting-bugs.rst <reportingbugs>` - document for details. + possible will help. Please read + 'Documentation/admin-guide/reporting-issues.rst' for details. - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you cannot change values or set break points.) To do this, first compile the diff --git a/Documentation/admin-guide/acpi/cppc_sysfs.rst b/Documentation/admin-guide/acpi/cppc_sysfs.rst index a4b99afbe331..fccf22114e85 100644 --- a/Documentation/admin-guide/acpi/cppc_sysfs.rst +++ b/Documentation/admin-guide/acpi/cppc_sysfs.rst @@ -8,7 +8,7 @@ CPPC ==== CPPC defined in the ACPI spec describes a mechanism for the OS to manage the -performance of a logical processor on a contigious and abstract performance +performance of a logical processor on a contiguous and abstract performance scale. CPPC exposes a set of registers to describe abstract performance scale, to request performance levels and to measure per-cpu delivered performance. @@ -45,7 +45,7 @@ for each cpu X:: * lowest_freq : CPU frequency corresponding to lowest_perf (in MHz). * nominal_freq : CPU frequency corresponding to nominal_perf (in MHz). The above frequencies should only be used to report processor performance in - freqency instead of abstract scale. These values should not be used for any + frequency instead of abstract scale. These values should not be used for any functional decisions. * feedback_ctrs : Includes both Reference and delivered performance counter. diff --git a/Documentation/admin-guide/binderfs.rst b/Documentation/admin-guide/binderfs.rst index 8243af9b3510..199d84314a14 100644 --- a/Documentation/admin-guide/binderfs.rst +++ b/Documentation/admin-guide/binderfs.rst @@ -70,5 +70,5 @@ Deleting binder Devices Binderfs binder devices can be deleted via `unlink() <unlink_>`_. This means that the `rm() <rm_>`_ tool can be used to delete them. Note that the ``binder-control`` device cannot be deleted since this would make the binderfs -instance unuseable. The ``binder-control`` device will be deleted when the +instance unusable. The ``binder-control`` device will be deleted when the binderfs instance is unmounted and all references to it have been dropped. diff --git a/Documentation/admin-guide/blockdev/paride.rst b/Documentation/admin-guide/blockdev/paride.rst index 87b4278bf314..e1ce90af602a 100644 --- a/Documentation/admin-guide/blockdev/paride.rst +++ b/Documentation/admin-guide/blockdev/paride.rst @@ -220,7 +220,7 @@ example:: Finally, you can load high-level drivers for each kind of device that you have connected. By default, each driver will autoprobe for a single device, but you can support up to four similar devices by giving their -individual co-ordinates when you load the driver. +individual coordinates when you load the driver. For example, if you had two no-name CD-ROM drives both using the KingByte KBIC-951A adapter, one on port 0x378 and the other on 0x3bc diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index a6fd1f9b5faf..700329d25f57 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -266,6 +266,7 @@ line of text and contains the following stats separated by whitespace: No memory is allocated for such pages. pages_compacted the number of pages freed during compaction huge_pages the number of incompressible pages + huge_pages_since the number of incompressible pages since zram set up ================ ============================================================= File /sys/block/zram<id>/bd_stat @@ -334,6 +335,11 @@ Admin can request writeback of those idle pages at right timing via:: With the command, zram writeback idle pages from memory to the storage. +If admin want to write a specific page in zram device to backing device, +they could write a page index into the interface. + + echo "page_index=1251" > /sys/block/zramX/writeback + If there are lots of write IO with flash device, potentially, it has flash wearout problem so that admin needs to design write limitation to guarantee storage health for entire product life. @@ -360,7 +366,7 @@ like below:: /sys/block/zram0/writeback_limit. $ echo 1 > /sys/block/zram0/writeback_limit_enable -If admins want to allow further write again once the bugdet is exhausted, +If admins want to allow further write again once the budget is exhausted, he could do it like below:: $ echo $((400<<MB_SHIFT>>4K_SHIFT)) > \ diff --git a/Documentation/admin-guide/bug-bisect.rst b/Documentation/admin-guide/bug-bisect.rst index 59567da344e8..325c5d0ed34a 100644 --- a/Documentation/admin-guide/bug-bisect.rst +++ b/Documentation/admin-guide/bug-bisect.rst @@ -15,7 +15,7 @@ give up. Report as much as you have found to the relevant maintainer. See MAINTAINERS for who that is for the subsystem you have worked on. Before you submit a bug report read -:ref:`Documentation/admin-guide/reporting-bugs.rst <reportingbugs>`. +'Documentation/admin-guide/reporting-issues.rst'. Devices not appearing ===================== diff --git a/Documentation/admin-guide/bug-hunting.rst b/Documentation/admin-guide/bug-hunting.rst index f7c80f4649fc..95299b08c405 100644 --- a/Documentation/admin-guide/bug-hunting.rst +++ b/Documentation/admin-guide/bug-hunting.rst @@ -263,7 +263,7 @@ Please notice that it will point to: - The last developers that touched the source code (if this is done inside a git tree). On the above example, Tejun and Bhaktipriya (in this - specific case, none really envolved on the development of this file); + specific case, none really involved on the development of this file); - The driver maintainer (Hans Verkuil); - The subsystem maintainer (Mauro Carvalho Chehab); - The driver and/or subsystem mailing list (linux-media@vger.kernel.org); diff --git a/Documentation/admin-guide/cgroup-v1/memcg_test.rst b/Documentation/admin-guide/cgroup-v1/memcg_test.rst index 3f7115e07b5d..45b94f7b3beb 100644 --- a/Documentation/admin-guide/cgroup-v1/memcg_test.rst +++ b/Documentation/admin-guide/cgroup-v1/memcg_test.rst @@ -133,18 +133,9 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. 8. LRU ====== - Each memcg has its own private LRU. Now, its handling is under global - VM's control (means that it's handled under global pgdat->lru_lock). - Almost all routines around memcg's LRU is called by global LRU's - list management functions under pgdat->lru_lock. - - A special function is mem_cgroup_isolate_pages(). This scans - memcg's private LRU and call __isolate_lru_page() to extract a page - from LRU. - - (By __isolate_lru_page(), the page is removed from both of global and - private LRU.) - + Each memcg has its own vector of LRUs (inactive anon, active anon, + inactive file, active file, unevictable) of pages from each node, + each LRU handled under a single lru_lock for that memcg and node. 9. Typical Tests. ================= @@ -219,13 +210,11 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. This is an easy way to test page migration, too. -9.5 mkdir/rmdir ---------------- +9.5 nested cgroups +------------------ - When using hierarchy, mkdir/rmdir test should be done. - Use tests like the following:: + Use tests like the following for testing nested cgroups:: - echo 1 >/opt/cgroup/01/memory/use_hierarchy mkdir /opt/cgroup/01/child_a mkdir /opt/cgroup/01/child_b diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst index 12757e63b26c..52688ae34461 100644 --- a/Documentation/admin-guide/cgroup-v1/memory.rst +++ b/Documentation/admin-guide/cgroup-v1/memory.rst @@ -77,6 +77,8 @@ Brief summary of control files. memory.soft_limit_in_bytes set/show soft limit of memory usage memory.stat show various statistics memory.use_hierarchy set/show hierarchical account enabled + This knob is deprecated and shouldn't be + used. memory.force_empty trigger forced page reclaim memory.pressure_level set memory pressure notifications memory.swappiness set/show swappiness parameter of vmscan @@ -285,20 +287,17 @@ When oom event notifier is registered, event will be delivered. 2.6 Locking ----------- - lock_page_cgroup()/unlock_page_cgroup() should not be called under - the i_pages lock. - - Other lock order is following: - - PG_locked. - mm->page_table_lock - pgdat->lru_lock - lock_page_cgroup. +Lock order is as follows: - In many cases, just lock_page_cgroup() is called. + Page lock (PG_locked bit of page->flags) + mm->page_table_lock or split pte_lock + lock_page_memcg (memcg->move_lock) + mapping->i_pages lock + lruvec->lru_lock. - per-zone-per-cgroup LRU (cgroup's private LRU) is just guarded by - pgdat->lru_lock, it has no lock of its own. +Per-node-per-memcgroup LRU (cgroup's private LRU) is guarded by +lruvec->lru_lock; PG_lru bit of page->flags is cleared before +isolating a page from its LRU under lruvec->lru_lock. 2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM) ----------------------------------------------- @@ -495,16 +494,13 @@ cgroup might have some charge associated with it, even though all tasks have migrated away from it. (because we charge against pages, not against tasks.) -We move the stats to root (if use_hierarchy==0) or parent (if -use_hierarchy==1), and no change on the charge except uncharging +We move the stats to parent, and no change on the charge except uncharging from the child. Charges recorded in swap information is not updated at removal of cgroup. Recorded information is discarded and a cgroup which uses swap (swapcache) will be charged as a new owner of it. -About use_hierarchy, see Section 6. - 5. Misc. interfaces =================== @@ -527,8 +523,6 @@ About use_hierarchy, see Section 6. write will still return success. In this case, it is expected that memory.kmem.usage_in_bytes == memory.usage_in_bytes. - About use_hierarchy, see Section 6. - 5.2 stat file ------------- @@ -675,31 +669,20 @@ hierarchy:: d e In the diagram above, with hierarchical accounting enabled, all memory -usage of e, is accounted to its ancestors up until the root (i.e, c and root), -that has memory.use_hierarchy enabled. If one of the ancestors goes over its -limit, the reclaim algorithm reclaims from the tasks in the ancestor and the -children of the ancestor. - -6.1 Enabling hierarchical accounting and reclaim ------------------------------------------------- +usage of e, is accounted to its ancestors up until the root (i.e, c and root). +If one of the ancestors goes over its limit, the reclaim algorithm reclaims +from the tasks in the ancestor and the children of the ancestor. -A memory cgroup by default disables the hierarchy feature. Support -can be enabled by writing 1 to memory.use_hierarchy file of the root cgroup:: +6.1 Hierarchical accounting and reclaim +--------------------------------------- - # echo 1 > memory.use_hierarchy - -The feature can be disabled by:: - - # echo 0 > memory.use_hierarchy +Hierarchical accounting is enabled by default. Disabling the hierarchical +accounting is deprecated. An attempt to do it will result in a failure +and a warning printed to dmesg. -NOTE1: - Enabling/disabling will fail if either the cgroup already has other - cgroups created below it, or if the parent cgroup has use_hierarchy - enabled. +For compatibility reasons writing 1 to memory.use_hierarchy will always pass:: -NOTE2: - When panic_on_oom is set to "2", the whole system will panic in - case of an OOM event in any cgroup. + # echo 1 > memory.use_hierarchy 7. Soft limits ============== diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 608d7c279396..63521cd36ce5 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1274,6 +1274,9 @@ PAGE_SIZE multiple when read back. kernel_stack Amount of memory allocated to kernel stacks. + pagetables + Amount of memory allocated for page tables. + percpu(npn) Amount of memory used for storing per-cpu kernel data structures. @@ -1300,6 +1303,14 @@ PAGE_SIZE multiple when read back. Amount of memory used in anonymous mappings backed by transparent hugepages + file_thp + Amount of cached filesystem data backed by transparent + hugepages + + shmem_thp + Amount of shm, tmpfs, shared anonymous mmap()s backed by + transparent hugepages + inactive_anon, active_anon, inactive_file, active_file, unevictable Amount of memory, swap-backed and filesystem-backed, on the internal memory management lists used by the diff --git a/Documentation/admin-guide/cifs/introduction.rst b/Documentation/admin-guide/cifs/introduction.rst index 0b98f672d36f..cc2851d93d17 100644 --- a/Documentation/admin-guide/cifs/introduction.rst +++ b/Documentation/admin-guide/cifs/introduction.rst @@ -9,7 +9,7 @@ Introduction PC operating systems. New and improved versions of CIFS are now called SMB2 and SMB3. Use of SMB3 (and later, including SMB3.1.1) is strongly preferred over using older dialects like CIFS due to - security reaasons. All modern dialects, including the most recent, + security reasons. All modern dialects, including the most recent, SMB3.1.1 are supported by the CIFS VFS module. The SMB3 protocol is implemented and supported by all major file servers such as all modern versions of Windows (including Windows 2016 diff --git a/Documentation/admin-guide/cifs/usage.rst b/Documentation/admin-guide/cifs/usage.rst index 7b32d5063803..b6d9f02bc12b 100644 --- a/Documentation/admin-guide/cifs/usage.rst +++ b/Documentation/admin-guide/cifs/usage.rst @@ -115,7 +115,7 @@ later source tree in docs/manpages/mount.cifs.8 Allowing User Unmounts ====================== -To permit users to ummount directories that they have user mounted (see above), +To permit users to unmount directories that they have user mounted (see above), the utility umount.cifs may be used. It may be invoked directly, or if umount.cifs is placed in /sbin, umount can invoke the cifs umount helper (at least for most versions of the umount utility) for umount of cifs @@ -197,7 +197,7 @@ that is ignored by local server applications and non-cifs clients and that will not be traversed by the Samba server). This is opaque to the Linux client application using the cifs vfs. Absolute symlinks will work to Samba 3.0.5 or later, but only for remote clients using the CIFS Unix extensions, and will -be invisbile to Windows clients and typically will not affect local +be invisible to Windows clients and typically will not affect local applications running on the same server as Samba. Use instructions @@ -267,7 +267,7 @@ would be forbidden for Windows/CIFS semantics) as long as the server is configured for Unix Extensions (and the client has not disabled /proc/fs/cifs/LinuxExtensionsEnabled). In addition the mount option ``mapposix`` can be used on CIFS (vers=1.0) to force the mapping of -illegal Windows/NTFS/SMB characters to a remap range (this mount parm +illegal Windows/NTFS/SMB characters to a remap range (this mount parameter is the default for SMB3). This remap (``mapposix``) range is also compatible with Mac (and "Services for Mac" on some older Windows). diff --git a/Documentation/admin-guide/device-mapper/dm-crypt.rst b/Documentation/admin-guide/device-mapper/dm-crypt.rst index bc28a9527ee5..1a6753b76dbb 100644 --- a/Documentation/admin-guide/device-mapper/dm-crypt.rst +++ b/Documentation/admin-guide/device-mapper/dm-crypt.rst @@ -46,7 +46,7 @@ Parameters:: capi:authenc(hmac(sha256),xts(aes))-random capi:rfc7539(chacha20,poly1305)-random - The /proc/crypto contains a list of curently loaded crypto modes. + The /proc/crypto contains a list of currently loaded crypto modes. <key> Key used for encryption. It is encoded either as a hexadecimal number @@ -92,7 +92,7 @@ Parameters:: <#opt_params> Number of optional parameters. If there are no optional parameters, - the optional paramaters section can be skipped or #opt_params can be zero. + the optional parameters section can be skipped or #opt_params can be zero. Otherwise #opt_params is the number of following arguments. Example of optional parameters section: diff --git a/Documentation/admin-guide/device-mapper/dm-integrity.rst b/Documentation/admin-guide/device-mapper/dm-integrity.rst index 3ab4f7756a6e..4e6f504474ac 100644 --- a/Documentation/admin-guide/device-mapper/dm-integrity.rst +++ b/Documentation/admin-guide/device-mapper/dm-integrity.rst @@ -117,7 +117,7 @@ journal_watermark:number commit_time:number Commit time in milliseconds. When this time passes, the journal is - written. The journal is also written immediatelly if the FLUSH + written. The journal is also written immediately if the FLUSH request is received. internal_hash:algorithm(:key) (the key is optional) @@ -147,7 +147,7 @@ journal_crypt:algorithm(:key) (the key is optional) "salsa20" or "ctr(aes)"). The journal contains history of last writes to the block device, - an attacker reading the journal could see the last sector nubmers + an attacker reading the journal could see the last sector numbers that were written. From the sector numbers, the attacker can infer the size of files that were written. To protect against this situation, you can encrypt the journal. diff --git a/Documentation/admin-guide/device-mapper/dm-raid.rst b/Documentation/admin-guide/device-mapper/dm-raid.rst index 7ef9fe63b3d4..bb17e26e3c1b 100644 --- a/Documentation/admin-guide/device-mapper/dm-raid.rst +++ b/Documentation/admin-guide/device-mapper/dm-raid.rst @@ -418,6 +418,6 @@ Version History specific devices are requested via rebuild. Fix RAID leg rebuild errors. 1.15.0 Fix size extensions not being synchronized in case of new MD bitmap - pages allocated; also fix those not occuring after previous reductions + pages allocated; also fix those not occurring after previous reductions 1.15.1 Fix argument count and arguments for rebuild/write_mostly/journal_(dev|mode) on the status line. diff --git a/Documentation/admin-guide/device-mapper/dm-zoned.rst b/Documentation/admin-guide/device-mapper/dm-zoned.rst index e635041351bc..0fac051caeac 100644 --- a/Documentation/admin-guide/device-mapper/dm-zoned.rst +++ b/Documentation/admin-guide/device-mapper/dm-zoned.rst @@ -24,7 +24,7 @@ The dm-zoned implementation is simple and minimizes system overhead (CPU and memory usage as well as storage capacity loss). For a 10TB host-managed disk with 256 MB zones, dm-zoned memory usage per disk instance is at most 4.5 MB and as little as 5 zones will be used -internally for storing metadata and performaing reclaim operations. +internally for storing metadata and performing reclaim operations. dm-zoned target devices are formatted and checked using the dmzadm utility available at: @@ -102,7 +102,7 @@ the buffer zone assigned. If the accessed chunk has no mapping, or the accessed blocks are invalid, the read buffer is zeroed and the read operation terminated. -After some time, the limited number of convnetional zones available may +After some time, the limited number of conventional zones available may be exhausted (all used to map chunks or buffer sequential zones) and unaligned writes to unbuffered chunks become impossible. To avoid this situation, a reclaim process regularly scans used conventional zones and @@ -158,7 +158,7 @@ Ex:: dmzadm --format /dev/sdxx /dev/sdyy -Fomatted device(s) can be started with the dmzadm utility, too.: +Formatted device(s) can be started with the dmzadm utility, too.: Ex:: diff --git a/Documentation/admin-guide/device-mapper/verity.rst b/Documentation/admin-guide/device-mapper/verity.rst index 66f71f0dab1b..1a6b91368e59 100644 --- a/Documentation/admin-guide/device-mapper/verity.rst +++ b/Documentation/admin-guide/device-mapper/verity.rst @@ -69,7 +69,7 @@ Construction Parameters <#opt_params> Number of optional parameters. If there are no optional parameters, - the optional paramaters section can be skipped or #opt_params can be zero. + the optional parameters section can be skipped or #opt_params can be zero. Otherwise #opt_params is the number of following arguments. Example of optional parameters section: @@ -134,7 +134,12 @@ root_hash_sig_key_desc <key_description> the pkcs7 signature of the roothash. The pkcs7 signature is used to validate the root hash during the creation of the device mapper block device. Verification of roothash depends on the config DM_VERITY_VERIFY_ROOTHASH_SIG - being set in the kernel. + being set in the kernel. The signatures are checked against the builtin + trusted keyring by default, or the secondary trusted keyring if + DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING is set. The secondary + trusted keyring includes by default the builtin trusted keyring, and it can + also gain new certificates at run time if they are signed by a certificate + already in the secondary trusted keyring. Theory of operation =================== diff --git a/Documentation/admin-guide/device-mapper/writecache.rst b/Documentation/admin-guide/device-mapper/writecache.rst index d3d7690f5e8d..dce0184e07ca 100644 --- a/Documentation/admin-guide/device-mapper/writecache.rst +++ b/Documentation/admin-guide/device-mapper/writecache.rst @@ -37,10 +37,10 @@ Constructor parameters: autocommit_blocks n (default: 64 for pmem, 65536 for ssd) when the application writes this amount of blocks without issuing the FLUSH request, the blocks are automati |