path: root/Documentation/filesystems/tmpfs.txt
diff options
authorLee Schermerhorn <lee.schermerhorn@hp.com>2010-05-24 14:32:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 08:06:57 -0700
commit971ada0f6659488c3f36aed4c6f7670ff5ce4368 (patch)
tree41cae3f0baf63eca482e4e17c3081cc6a8a86439 /Documentation/filesystems/tmpfs.txt
parent15d77835ac48dbc2d4884376ea6a08b65b1c40ba (diff)
mempolicy: document cpuset interaction with tmpfs mpol mount option
Update Documentation/filesystems/tmpfs.txt to describe the interaction of tmpfs mount option memory policy with tasks' cpuset mems_allowed. Note: the mount(8) man page [in the util-linux-ng package] requires similiar updates. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/filesystems/tmpfs.txt')
1 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/filesystems/tmpfs.txt b/Documentation/filesystems/tmpfs.txt
index fe09a2cb1858..98ef55124158 100644
--- a/Documentation/filesystems/tmpfs.txt
+++ b/Documentation/filesystems/tmpfs.txt
@@ -94,11 +94,19 @@ 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