linux/include
Lee Schermerhorn 71fe804b6d mempolicy: use struct mempolicy pointer in shmem_sb_info
This patch replaces the mempolicy mode, mode_flags, and nodemask in the
shmem_sb_info struct with a struct mempolicy pointer, initialized to NULL.
This removes dependency on the details of mempolicy from shmem.c and hugetlbfs
inode.c and simplifies the interfaces.

mpol_parse_str() in mempolicy.c is changed to return, via a pointer to a
pointer arg, a struct mempolicy pointer on success.  For MPOL_DEFAULT, the
returned pointer is NULL.  Further, mpol_parse_str() now takes a 'no_context'
argument that causes the input nodemask to be stored in the w.user_nodemask of
the created mempolicy for use when the mempolicy is installed in a tmpfs inode
shared policy tree.  At that time, any cpuset contextualization is applied to
the original input nodemask.  This preserves the previous behavior where the
input nodemask was stored in the superblock.  We can think of the returned
mempolicy as "context free".

Because mpol_parse_str() is now calling mpol_new(), we can remove from
mpol_to_str() the semantic checks that mpol_new() already performs.

Add 'no_context' parameter to mpol_to_str() to specify that it should format
the nodemask in w.user_nodemask for 'bind' and 'interleave' policies.

Change mpol_shared_policy_init() to take a pointer to a "context free" struct
mempolicy and to create a new, "contextualized" mempolicy using the mode,
mode_flags and user_nodemask from the input mempolicy.

  Note: we know that the mempolicy passed to mpol_to_str() or
  mpol_shared_policy_init() from a tmpfs superblock is "context free".  This
  is currently the only instance thereof.  However, if we found more uses for
  this concept, and introduced any ambiguity as to whether a mempolicy was
  context free or not, we could add another internal mode flag to identify
  context free mempolicies.  Then, we could remove the 'no_context' argument
  from mpol_to_str().

Added shmem_get_sbmpol() to return a reference counted superblock mempolicy,
if one exists, to pass to mpol_shared_policy_init().  We must add the
reference under the sb stat_lock to prevent races with replacement of the mpol
by remount.  This reference is removed in mpol_shared_policy_init().

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: another build fix]
[akpm@linux-foundation.org: yet another build fix]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:25 -07:00
..
acpi
asm-alpha mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-arm mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-avr32 mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-blackfin
asm-cris mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-frv mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-generic
asm-h8300
asm-ia64 mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-m32r mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-m68k mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-m68knommu
asm-mips mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-mn10300 mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-parisc mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-powerpc mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-ppc mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-s390 s390: implement pte special bit 2008-04-28 08:58:23 -07:00
asm-sh mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-sparc mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-sparc64 mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-um mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-v850
asm-x86 mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
asm-xtensa mm: introduce pte_special pte bit 2008-04-28 08:58:23 -07:00
crypto
keys
linux mempolicy: use struct mempolicy pointer in shmem_sb_info 2008-04-28 08:58:25 -07:00
math-emu
media
mtd
net
pcmcia
rdma
rxrpc
scsi
sound
video
xen
Kbuild