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-rw-r--r--Documentation/filesystems/tmpfs.txt16
1 files changed, 14 insertions, 2 deletions
diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt
index 3015da0c6b2..98ef5512415 100644
--- a/Documentation/filesystems/tmpfs.txt
+++ b/Documentation/filesystems/tmpfs.txt
@@ -82,21 +82,31 @@ 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
+A memory policy with a valid NodeList will be saved, as specified, for
+use at file creation time. When a task allocates a file in the file
+system, the mount option memory policy will be applied with a NodeList,
+if any, modified by the calling task's cpuset constraints
+[See Documentation/cgroups/cpusets.txt] and any optional flags, listed
+below. If the resulting NodeLists is the empty set, the effective memory
+policy for the file will revert to "default" policy.
+
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.
+memory allocation policy mode flags and their effect on memory policy.
=static is equivalent to MPOL_F_STATIC_NODES
=relative is equivalent to MPOL_F_RELATIVE_NODES
@@ -134,3 +144,5 @@ Author:
Christoph Rohland <cr@sap.com>, 1.12.01
Updated:
Hugh Dickins, 4 June 2007
+Updated:
+ KOSAKI Motohiro, 16 Mar 2010