[PATCH] tmpfs: fix mount mpol nodelist parsing

I've been dissatisfied with the mpol_nodelist mount option which was
added to tmpfs earlier in -rc.  Replace it by mpol=policy:nodelist.

And it was broken: a nodelist is a comma-separated list of numbers and
ranges; the mount options are a comma-separated list of token=values.
Whoops, blindly strsep'ing on commas doesn't work so well: since we've
no numeric tokens, and unlikely to add them, use that to distinguish.

Move the mpol= parsing to shmem_parse_mpol under CONFIG_NUMA, reject
all its options as invalid if not NUMA.  /proc shows MPOL_PREFERRED
as "prefer", so use that name for the policy instead of "preferred".

Enforce that mpol=default has no nodelist; that mpol=prefer has one
node only; that mpol=bind has a nodelist; but let mpol=interleave use
node_online_map if no nodelist given.  Describe this in tmpfs.txt.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Robin Holt <holt@sgi.com>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Hugh Dickins
2006-02-21 23:49:47 +00:00
committed by Linus Torvalds
parent 808c783e9b
commit b00dc3ad74
2 changed files with 81 additions and 21 deletions

View File

@@ -79,15 +79,18 @@ that instance in a system with many cpus making intensive use of it.
tmpfs has a mount option to set the NUMA memory allocation policy for
all files in that instance:
mpol=interleave prefers to allocate memory from each node in turn
mpol=default prefers to allocate memory from the local node
mpol=bind prefers to allocate from mpol_nodelist
mpol=preferred prefers to allocate from first node in mpol_nodelist
all files in that instance (if CONFIG_NUMA is enabled) - which can be
adjusted on the fly via 'mount -o remount ...'
The following mount option is used in conjunction with mpol=interleave,
mpol=bind or mpol=preferred:
mpol_nodelist: nodelist suitable for parsing with nodelist_parse.
mpol=default prefers to allocate memory from the local node
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
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
To specify the initial root directory you can use the following mount
@@ -109,4 +112,4 @@ 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>, 13 March 2005
Hugh Dickins <hugh@veritas.com>, 19 February 2006