Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platf...

[safe/jmp/linux-2.6] / Documentation / filesystems / tmpfs.txt

diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt
index 6dd0508..fe09a2c 100644 (file)
--- a/Documentation/filesystems/tmpfs.txt
+++ b/Documentation/filesystems/tmpfs.txt
@@ -82,22 +82,36 @@ tmpfs has a mount option to set the NUMA memory allocation policy for
 all files in that instance (if CONFIG_NUMA is enabled) - which can be
 adjusted on the fly via 'mount -o remount ...'
 
-mpol=default             prefers to allocate memory from the local node
+mpol=default             use the process allocation policy
+                         (see set_mempolicy(2))
 mpol=prefer:Node         prefers to allocate memory from the given Node
 mpol=bind:NodeList       allocates memory only from nodes in NodeList
 mpol=interleave          prefers to allocate from each node in turn
 mpol=interleave:NodeList allocates from each node of NodeList in turn
+mpol=local              prefers to allocate memory from the local node
 
 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 +135,6 @@ RAM/SWAP in 10240 inodes and it is only accessible by root.
 Author:
    Christoph Rohland <cr@sap.com>, 1.12.01
 Updated:
-   Hugh Dickins <hugh@veritas.com>, 19 February 2006
+   Hugh Dickins, 4 June 2007
+Updated:
+   KOSAKI Motohiro, 16 Mar 2010