Better save the sigmask instead of throwing it away so it can be restored.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Prodive a MODALIAS= enviroment variable for devices on the mac-io bus.
Change the buffer length counter to not waste memory by advancing the
pointer for the next string too far.  Tested on an ibook1 with modular
pmac_zilog.
Signed-off-by: NOlaf Hering <olh@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- kexec.h is included from assembly code, thus C code must be properly
  protected.

- (embedded) ppc32 systems use machine_kexec_simple whose declaration
  vanished during a recent powerpc merge change.
Signed-off-by: NAlbert Herranz <albert_herranz@yahoo.es>
Cc: <fastboot@osdl.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Remove the SELinux security structure magic number fields and tests, along
with some unnecessary tests for NULL security pointers.  These fields and
tests are leftovers from the early attempts to support SELinux as a
loadable module during LSM development.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch changes the SELinux file_alloc_security function to use
GFP_KERNEL rather than GFP_ATOMIC; the use of GFP_ATOMIC appears to be a
remnant of when this function was being called with the files_lock spinlock
held, and is no longer necessary.  Please apply.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the SELinux mprotect checks on executable mappings so that they are not
re-applied when the mapping is already executable as well as cleaning up
the code.  This avoids a situation where e.g.  an application is prevented
from removing PROT_WRITE on an already executable mapping previously
authorized via execmem permission due to an execmod denial.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

mm/slab.c:1522:13: error: incompatible types for operation (&)
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix kernel-doc for calculate_slab_order().
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix kzalloc() and kstrdup() caller report for CONFIG_DEBUG_SLAB.  We must
pass the caller to __cache_alloc() instead of directly doing
__builtin_return_address(0) there; otherwise kzalloc() and kstrdup() are
reported as the allocation site instead of the real one.

Thanks to Valdis Kletnieks for reporting the problem and Steven Rostedt for
the original idea.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Sometimes it's nice to know who's calling.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Replace uses of kmem_cache_t with proper struct kmem_cache in mm/slab.c.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Rename the ac_data() function to more descriptive cpu_cache_get().
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce virt_to_cache() and virt_to_slab() functions to reduce duplicate
code and introduce a proper abstraction should we want to support other kind
of mapping for address to slab and cache (eg.  for vmalloc() or I/O memory).
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

From: Manfred Spraul <manfred@colorfullife.com>

Reduce the amount of inline functions in slab to the functions that
are used in the hot path:

  - no inline for debug functions
  - no __always_inline, inline is already __always_inline
  - remove inline from a few numa support functions.

Before:

   text    data     bss     dec     hex filename
  13588     752      48   14388    3834 mm/slab.o (defconfig)
  16671    2492      48   19211    4b0b mm/slab.o (numa)

After:

   text    data     bss     dec     hex filename
  13366     752      48   14166    3756 mm/slab.o (defconfig)
  16230    2492      48   18770    4952 mm/slab.o (numa)
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Create two helper functions slab_get_obj() and slab_put_obj() to replace
duplicated code in mm/slab.c
Signed-off-by: NMatthew Dobson <colpatch@us.ibm.com>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Create a helper function, slab_destroy_objs() which called from
slab_destroy().  This makes slab_destroy() smaller and more readable, and
moves ifdefs outside the function body.
Signed-off-by: NMatthew Dobson <colpatch@us.ibm.com>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clean up cache_estimate() in mm/slab.c and improves the algorithm from O(n) to
O(1).  We first calculate the maximum number of objects a slab can hold after
struct slab and kmem_bufctl_t for each object has been given enough space.
After that, to respect alignment rules, we decrease the number of objects if
necessary.  As required padding is at most align-1 and memory of obj_size is
at least align, it is always enough to decrease number of objects by one.

The optimization was originally made by Balbir Singh with more improvements
from Steven Rostedt.  Manfred Spraul provider further modifications: no loop
at all for the off-slab case and added comments to explain the background.
Acked-by: NBalbir Singh <bsingharora@gmail.com>
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

I noticed the code for index_of is a creative way of finding the cache
index using the compiler to optimize to a single hard coded number.  But
I couldn't help noticing that it uses two methods to let you know that
someone used it wrong.  One is at compile time (the correct way), and
the other is at run time (not good).
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Clean up kmem_cache_alloc_node a bit.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

An object cache has two different object lengths:

  - the amount of memory available for the user (object size)
  - the amount of memory allocated internally (buffer size)

This patch does some renames to make the code reflect that better.
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Migrate a page with buffers without requiring writeback

This introduces a new address space operation migratepage() that may be used
by a filesystem to implement its own version of page migration.

A version is provided that migrates buffers attached to pages.  Some
filesystems (ext2, ext3, xfs) are modified to utilize this feature.

The swapper address space operation are modified so that a regular
migrate_page() will occur for anonymous pages without writeback (migrate_pages
forces every anonymous page to have a swap entry).
Signed-off-by: NMike Kravetz <kravetz@us.ibm.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Modify policy layer to support direct page migration

- Add migrate_pages_to() allowing the migration of a list of pages to a a
  specified node or to vma with a specific allocation policy in sets of
  MIGRATE_CHUNK_SIZE pages

- Modify do_migrate_pages() to do a staged move of pages from the source
  nodes to the target nodes.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add remove_from_swap

remove_from_swap() allows the restoration of the pte entries that existed
before page migration occurred for anonymous pages by walking the reverse
maps.  This reduces swap use and establishes regular pte's without the need
for page faults.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add direct migration support with fall back to swap.

Direct migration support on top of the swap based page migration facility.

This allows the direct migration of anonymous pages and the migration of file
backed pages by dropping the associated buffers (requires writeout).

Fall back to swap out if necessary.

The patch is based on lots of patches from the hotplug project but the code
was restructured, documented and simplified as much as possible.

Note that an additional patch that defines the migrate_page() method for
filesystems is necessary in order to avoid writeback for anonymous and file
backed pages.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NMike Kravetz <kravetz@us.ibm.com>
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Check for PageSwapCache after looking up and locking a swap page.

The page migration code may change a swap pte to point to a different page
under lock_page().

If that happens then the vm must retry the lookup operation in the swap space
to find the correct page number.  There are a couple of locations in the VM
where a lock_page() is done on a swap page.  In these locations we need to
check afterwards if the page was migrated.  If the page was migrated then the
old page that was looked up before was freed and no longer has the
PageSwapCache bit set.
Signed-off-by: NHirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: NDave Hansen <haveblue@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

If large amounts of zone memory are used by empty slabs then zone_reclaim
becomes uneffective.  This patch shakes the slab a bit.

The problem with this patch is that the slab reclaim is not containable to a
zone.  Thus slab reclaim may affect the whole system and be extremely slow.
This also means that we cannot determine how many pages were freed in this
zone.  Thus we need to go off node for at least one allocation.

The functionality is disabled by default.

We could modify the shrinkers to take a zone parameter but that would be quite
invasive.  Better ideas are welcome.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In some situations one may want zone_reclaim to behave differently.  For
example a process writing large amounts of memory will spew unto other nodes
to cache the writes if many pages in a zone become dirty.  This may impact the
performance of processes running on other nodes.

Allowing writes during reclaim puts a stop to that behavior and throttles the
process by restricting the pages to the local zone.

Similarly one may want to contain processes to local memory by enabling
regular swap behavior during zone_reclaim.  Off node memory allocation can
then be controlled through memory policies and cpusets.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Currently the zone_reclaim code has a fixed window of 30 seconds of off node
allocations should a local zone have no unused pagecache pages left.  Reclaim
will be attempted again after this timeout period to avoid repeated useless
scans for memory.  This is also useful to established sufficiently large off
node allocation chunks to relieve the local node.

It may be beneficial to adjust that time period for some special situations.
For example if memory use was exceeding node capacity one may want to give up
for longer periods of time.  If memory spikes intermittendly then one may want
to shorten the time period to reduce the number of off node allocations.

This patch allows just that....
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Instead of scanning all the pages in a zone, imitate real swap and scan
only a portion of the pages and gradually scan more if we do not free up
enough pages.  This avoids a zone suddenly loosing all unused pagecache
pages (we may after all access some of these again so they deserve another
chance) but it still frees up large chunks of memory if a zone only
contains unused pagecache pages.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

zone_reclaim should leave that to the real swapper.  We are only interested
in evicting unmapped pages.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

2.6.15's hugepage faulting introduced huge_pages_needed accounting into
hugetlbfs: to count how many pages are already in cache, for spot check on
how far a new mapping may be allowed to extend the file.  But it's muddled:
each hugepage found covers HPAGE_SIZE, not PAGE_SIZE.  Once pages were
already in cache, it would overshoot, wrap its hugepages count backwards,
and so fail a harmless repeat mapping with -ENOMEM.  Fixes the problem
found by Don Dupuis.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Acked-By: NAdam Litke <agl@us.ibm.com>
Acked-by: NWilliam Irwin <wli@holomorphy.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Improve the performance of slab_put_obj().  Without the cast, gcc considers
ptrdiff_t a 64 bit signed integer and ends up emitting code to use a full
signed 128 bit divide on EM64T, which is substantially slower than a 32 bit
unsigned divide.

I noticed this when looking at the profile of a case where the slab balance
is just on edge and thrashes back and forth freeing a block.
Signed-off-by: NBenjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- If we only reclaim nr_pages then its okay to stay on node.
  Switch from > to >= for the comparison.

- vm_table[] entry for zone_reclaim_mode is a bit screwed up.

- Add empty lines around shrink_zone to show that this is the
  central function to be called.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make sc->may_writepage control the writeout behavior of shrink_list.

Remove the laptop_mode trick from shrink_list and instead set may_writepage
in try_to_free_pages properly.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

GFP_ZONETYPES calculate from GFP_ZONEMASK

GFP_ZONETYPES's value is directly related to the value of GFP_ZONEMASK.  It
takes one of two forms depending whether the top bit of GFP_ZONEMASK is a
'loner'.  Supply both forms, enabling the loner.
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

GFP_ZONETYPES define using GFP_ZONEMASK and add commentry

Add commentry explaining the optimisation that we can apply to GFP_ZONETYPES
when the leftmost bit is a 'loaner', it can only be set in isolation.
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Zone reclaim is usually only run on the local node.  Headless nodes do not
have any local processors.  This patch checks for headless nodes and
performs zone reclaim on them.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndy Whitcroft <apw@shadowen.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Ensure that the performance of off node pages stays the same as before.
Off node pagefault tests showed an 18% drop in performance without this
patch.

- Increase the timeout to 30 seconds to reduce the overhead.

- Move all code possible out of the off node hot path for zone reclaim
  (Sorry Andrew, the struct initialization had to be sacrificed).
  The read_page_state() bit us there.

- Check first for the timeout before any other checks.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

OpenBSD doesn't see "." correctly in directories created by Linux.  Copying
files over several KB will buy you infinite loop in __getblk_slow().
Copying files smaller than 1 KB seems to be OK.  Sometimes files will be
filled with zeros.  Sometimes incorrectly copied file will reappear after
next file with truncated size.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The flattened device tree is the only supported way of booting ARCH=powerpc
kernels on non Open Firmware machines.  The documentation for the flattened
tree format and contents has been discussed on mailing lists and lately has
been living in the dtc git tree.  Really, it ought to go in the kernel's
Documentation directory for maximum visibility.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>