X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=Documentation%2Ffilesystems%2Ftmpfs.txt;h=222437efd75a8231751c83a9d68195364b22ad62;hb=7110879cf2afbfb7af79675f5ff109e63d631c25;hp=1773106976a26ebf7aaf425141797ea43f4563f1;hpb=58a343f22e8ef987b90e34bbef7f1455e3bb5a15;p=linux-2.6-omap-h63xx.git diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt index 1773106976a..222437efd75 100644 --- a/Documentation/filesystems/tmpfs.txt +++ b/Documentation/filesystems/tmpfs.txt @@ -39,7 +39,7 @@ tmpfs has the following uses: tmpfs /dev/shm tmpfs defaults 0 0 Remember to create the directory that you intend to mount tmpfs on - if necessary (/dev/shm is automagically created if you use devfs). + if necessary. This mount is _not_ needed for SYSV shared memory. The internal mount is used for that. (In the 2.3 kernel versions it was @@ -63,7 +63,7 @@ size: The limit of allocated bytes for this tmpfs instance. The nr_blocks: The same as size, but in blocks of PAGE_CACHE_SIZE. nr_inodes: The maximum number of inodes for this instance. The default is half of the number of your physical RAM pages, or (on a - a machine with highmem) the number of lowmem RAM pages, + machine with highmem) the number of lowmem RAM pages, whichever is the lower. These parameters accept a suffix k, m or g for kilo, mega and giga and @@ -92,12 +92,24 @@ NodeList format is a comma-separated list of decimal numbers and ranges, a range being two hyphen-separated decimal numbers, the smallest and largest node numbers in the range. For example, mpol=bind:0-3,5,7,9-15 +NUMA memory allocation policies have optional flags that can be used in +conjunction with their modes. These optional flags can be specified +when tmpfs is mounted by appending them to the mode before the NodeList. +See Documentation/vm/numa_memory_policy.txt for a list of all available +memory allocation policy mode flags. + + =static is equivalent to MPOL_F_STATIC_NODES + =relative is equivalent to MPOL_F_RELATIVE_NODES + +For example, mpol=bind=static:NodeList, is the equivalent of an +allocation policy of MPOL_BIND | MPOL_F_STATIC_NODES. + Note that trying to mount a tmpfs with an mpol option will fail if the running kernel does not support NUMA; and will fail if its nodelist -specifies a node >= MAX_NUMNODES. If your system relies on that tmpfs -being mounted, but from time to time runs a kernel built without NUMA -capability (perhaps a safe recovery kernel), or configured to support -fewer nodes, then it is advisable to omit the mpol option from automatic +specifies a node which is not online. If your system relies on that +tmpfs being mounted, but from time to time runs a kernel built without +NUMA capability (perhaps a safe recovery kernel), or with fewer nodes +online, then it is advisable to omit the mpol option from automatic mount options. It can be added later, when the tmpfs is already mounted on MountPoint, by 'mount -o remount,mpol=Policy:NodeList MountPoint'. @@ -121,4 +133,4 @@ RAM/SWAP in 10240 inodes and it is only accessible by root. Author: Christoph Rohland , 1.12.01 Updated: - Hugh Dickins , 19 February 2006 + Hugh Dickins , 4 June 2007