From 3d08cd331c1adcf0d917392f7e527b3f00511748 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 24 May 2024 06:52:22 +0200 Subject: Merging upstream version 6.8. Signed-off-by: Daniel Baumann --- man5/tmpfs.5 | 281 ----------------------------------------------------------- 1 file changed, 281 deletions(-) delete mode 100644 man5/tmpfs.5 (limited to 'man5/tmpfs.5') diff --git a/man5/tmpfs.5 b/man5/tmpfs.5 deleted file mode 100644 index 55fc826..0000000 --- a/man5/tmpfs.5 +++ /dev/null @@ -1,281 +0,0 @@ -.\" Copyright (c) 2016 by Michael Kerrisk -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.TH tmpfs 5 2023-10-31 "Linux man-pages 6.7" -.SH NAME -tmpfs \- a virtual memory filesystem -.SH DESCRIPTION -The -.B tmpfs -facility allows the creation of filesystems whose contents reside -in virtual memory. -Since the files on such filesystems typically reside in RAM, -file access is extremely fast. -.P -The filesystem is automatically created when mounting -a filesystem with the type -.B tmpfs -via a command such as the following: -.P -.in +4n -.EX -$ sudo mount \-t tmpfs \-o size=10M tmpfs /mnt/mytmpfs -.EE -.in -.P -A -.B tmpfs -filesystem has the following properties: -.IP \[bu] 3 -The filesystem can employ swap space when physical memory pressure -demands it. -.IP \[bu] -The filesystem consumes only as much physical memory and swap space -as is required to store the current contents of the filesystem. -.IP \[bu] -During a remount operation -.RI ( "mount\ \-o\ remount" ), -the filesystem size can be changed -(without losing the existing contents of the filesystem). -.P -If a -.B tmpfs -filesystem is unmounted, its contents are discarded (lost). -.\" See mm/shmem.c:shmem_parse_options for options it supports. -.SS Mount options -The -.B tmpfs -filesystem supports the following mount options: -.TP -.BR size "=\fIbytes\fP" -Specify an upper limit on the size of the filesystem. -The size is given in bytes, and rounded up to entire pages. -The limit is removed if the size is -.BR 0 . -.IP -The size may have a -.BR k , -.BR m , -or -.B g -suffix for Ki, Mi, Gi (binary kilo (kibi), binary mega (mebi), and binary giga -(gibi)). -.IP -The size may also have a % suffix to limit this instance to a percentage of -physical RAM. -.IP -The default, when neither -.B size -nor -.B nr_blocks -is specified, is -.IR size=50% . -.TP -.BR nr_blocks "=\fIblocks\fP" -The same as -.BR size , -but in blocks of -.BR PAGE_CACHE_SIZE . -.IP -Blocks may be specified with -.BR k , -.BR m , -or -.B g -suffixes like -.BR size , -but not a % suffix. -.TP -.BR nr_inodes "=\fIinodes\fP" -The maximum number of inodes for this instance. -The default is half of the number of your physical RAM pages, or (on a -machine with highmem) the number of lowmem RAM pages, whichever is smaller. -The limit is removed if the number is -.BR 0 . -.IP -Inodes may be specified with -.BR k , -.BR m , -or -.B g -suffixes like -.BR size , -but not a % suffix. -.TP -.BR noswap "(since Linux 6.4)" -.\" commit 2c6efe9cf2d7841b75fe38ed1adbd41a90f51ba0 -Disables swap. -Remounts must respect the original settings. -By default swap is enabled. -.TP -.BR mode "=\fImode\fP" -Set initial permissions of the root directory. -.TP -.BR gid "=\fIgid\fP (since Linux 2.5.7)" -.\" Technically this is also in some version of Linux 2.4. -.\" commit 099445b489625b80b1d6687c9b6072dbeaca4096 -Set the initial group ID of the root directory. -.TP -.BR uid "=\fIuid\fP (since Linux 2.5.7)" -.\" Technically this is also in some version of Linux 2.4. -.\" commit 099445b489625b80b1d6687c9b6072dbeaca4096 -Set the initial user ID of the root directory. -.TP -.BR huge "=\fIhuge_option\fR (since Linux 4.7.0)" -.\" commit 5a6e75f8110c97e2a5488894d4e922187e6cb343 -Set the huge table memory allocation policy for all files in this instance (if -.B CONFIG_TRANSPARENT_HUGEPAGE -is enabled). -.IP -The -.I huge_option -value is one of the following: -.RS -.TP -.B never -Do not allocate huge pages. -This is the default. -.TP -.B always -Attempt to allocate huge pages every time a new page is needed. -.TP -.B within_size -Only allocate huge page if it will be fully within -.IR i_size . -Also respect -.BR fadvise (2) -and -.BR madvise (2) -hints -.TP -.B advise -Only allocate huge pages if requested with -.BR fadvise (2) -or -.BR madvise (2). -.TP -.B deny -For use in emergencies, to force the huge option off from all mounts. -.TP -.B force -Force the huge option on for all mounts; useful for testing. -.RE -.TP -.BR mpol "=\fImpol_option\fR (since Linux 2.6.15)" -.\" commit 7339ff8302fd70aabf5f1ae26e0c4905fa74a495 -Set the NUMA memory allocation policy for all files in this instance (if -.B CONFIG_NUMA -is enabled). -.IP -The -.I mpol_option -value is one of the following: -.RS -.TP -.B default -Use the process allocation policy (see -.BR set_mempolicy (2)). -.TP -.BR prefer ":\fInode\fP" -Preferably allocate memory from the given -.IR node . -.TP -.BR bind ":\fInodelist\fP" -Allocate memory only from nodes in -.IR nodelist . -.TP -.B interleave -Allocate from each node in turn. -.TP -.BR interleave ":\fInodelist\fP" -Allocate from each node of -.I in -turn. -.TP -.B local -Preferably allocate memory from the local node. -.RE -.IP -In the above, -.I nodelist -is a comma-separated list of decimal numbers and ranges -that specify NUMA nodes. -A range is a pair of hyphen-separated decimal numbers, -the smallest and largest node numbers in the range. -For example, -.IR mpol=bind:0\-3,5,7,9\-15 . -.SH VERSIONS -The -.B tmpfs -facility was added in Linux 2.4, as a successor to the older -.B ramfs -facility, which did not provide limit checking or -allow for the use of swap space. -.SH NOTES -In order for user-space tools and applications to create -.B tmpfs -filesystems, the kernel must be configured with the -.B CONFIG_TMPFS -option. -.P -The -.B tmpfs -filesystem supports extended attributes (see -.BR xattr (7)), -but -.I user -extended attributes are not permitted. -.P -An internal shared memory filesystem is used for -System V shared memory -.RB ( shmget (2)) -and shared anonymous mappings -.RB ( mmap (2) -with the -.B MAP_SHARED -and -.B MAP_ANONYMOUS -flags). -This filesystem is available regardless of whether -the kernel was configured with the -.B CONFIG_TMPFS -option. -.P -A -.B tmpfs -filesystem mounted at -.I /dev/shm -is used for the implementation of POSIX shared memory -.RB ( shm_overview (7)) -and POSIX semaphores -.RB ( sem_overview (7)). -.P -The amount of memory consumed by all -.B tmpfs -filesystems is shown in the -.I Shmem -field of -.I /proc/meminfo -and in the -.I shared -field displayed by -.BR free (1). -.P -The -.B tmpfs -facility was formerly called -.BR shmfs . -.SH SEE ALSO -.BR df (1), -.BR du (1), -.BR memfd_create (2), -.BR mmap (2), -.BR set_mempolicy (2), -.BR shm_open (3), -.BR mount (8) -.P -The kernel source files -.I Documentation/filesystems/tmpfs.txt -and -.IR Documentation/admin\-guide/mm/transhuge.rst . -- cgit v1.2.3