Commit Graph

167 Commits

Author SHA1 Message Date
Tang Chen c2974058a9 memory-hotplug: document and enable CONFIG_MOVABLE_NODE
Add help info for CONFIG_MOVABLE_NODE and permit its selection.

This option allows the user to online all memory of a node as movable
memory.  So that the whole node can be hotplugged.  Users who don't use
the hotplug feature are also fine with this option on since they won't
online memory as movable.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
[akpm@linux-foundation.org: tweak help text]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 15:02:12 -08:00
Linus Torvalds f6e858a00a Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc VM changes from Andrew Morton:
 "The rest of most-of-MM.  The other MM bits await a slab merge.

  This patch includes the addition of a huge zero_page.  Not a
  performance boost but it an save large amounts of physical memory in
  some situations.

  Also a bunch of Fujitsu engineers are working on memory hotplug.
  Which, as it turns out, was badly broken.  About half of their patches
  are included here; the remainder are 3.8 material."

However, this merge disables CONFIG_MOVABLE_NODE, which was totally
broken.  We don't add new features with "default y", nor do we add
Kconfig questions that are incomprehensible to most people without any
help text.  Does the feature even make sense without compaction or
memory hotplug?

* akpm: (54 commits)
  mm/bootmem.c: remove unused wrapper function reserve_bootmem_generic()
  mm/memory.c: remove unused code from do_wp_page()
  asm-generic, mm: pgtable: consolidate zero page helpers
  mm/hugetlb.c: fix warning on freeing hwpoisoned hugepage
  hwpoison, hugetlbfs: fix RSS-counter warning
  hwpoison, hugetlbfs: fix "bad pmd" warning in unmapping hwpoisoned hugepage
  mm: protect against concurrent vma expansion
  memcg: do not check for mm in __mem_cgroup_count_vm_event
  tmpfs: support SEEK_DATA and SEEK_HOLE (reprise)
  mm: provide more accurate estimation of pages occupied by memmap
  fs/buffer.c: remove redundant initialization in alloc_page_buffers()
  fs/buffer.c: do not inline exported function
  writeback: fix a typo in comment
  mm: introduce new field "managed_pages" to struct zone
  mm, oom: remove statically defined arch functions of same name
  mm, oom: remove redundant sleep in pagefault oom handler
  mm, oom: cleanup pagefault oom handler
  memory_hotplug: allow online/offline memory to result movable node
  numa: add CONFIG_MOVABLE_NODE for movable-dedicated node
  mm, memcg: avoid unnecessary function call when memcg is disabled
  ...
2012-12-13 13:11:15 -08:00
Lai Jiangshan 20b2f52b73 numa: add CONFIG_MOVABLE_NODE for movable-dedicated node
We need a node which only contains movable memory.  This feature is very
important for node hotplug.  If a node has normal/highmem, the memory may
be used by the kernel and can't be offlined.  If the node only contains
movable memory, we can offline the memory and the node.

All are prepared, we can actually introduce N_MEMORY.
add CONFIG_MOVABLE_NODE make we can use it for movable-dedicated node

[akpm@linux-foundation.org: fix Kconfig text]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Tested-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 17:38:34 -08:00
Rafael Aquini 18468d93e5 mm: introduce a common interface for balloon pages mobility
Memory fragmentation introduced by ballooning might reduce significantly
the number of 2MB contiguous memory blocks that can be used within a guest,
thus imposing performance penalties associated with the reduced number of
transparent huge pages that could be used by the guest workload.

This patch introduces a common interface to help a balloon driver on
making its page set movable to compaction, and thus allowing the system
to better leverage the compation efforts on memory defragmentation.

[akpm@linux-foundation.org: use PAGE_FLAGS_CHECK_AT_PREP, s/__balloon_page_flags/page_flags_cleared/, small cleanups]
[rientjes@google.com: allow balloon compaction for any system with memory compaction enabled, which is the defconfig]
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-11 17:22:26 -08:00
Rik van Riel 05106e6a54 mm: enable CONFIG_COMPACTION by default
Now that lumpy reclaim has been removed, compaction is the only way left
to free up contiguous memory areas.  It is time to just enable
CONFIG_COMPACTION by default.

Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:53 +09:00
Gerald Schaefer 15626062f4 thp, x86: introduce HAVE_ARCH_TRANSPARENT_HUGEPAGE
Cleanup patch in preparation for transparent hugepage support on s390.
Adding new architectures to the TRANSPARENT_HUGEPAGE config option can
make the "depends" line rather ugly, like "depends on (X86 || (S390 &&
64BIT)) && MMU".

This patch adds a HAVE_ARCH_TRANSPARENT_HUGEPAGE instead.  x86 already has
MMU "def_bool y", so the MMU check is superfluous there and
HAVE_ARCH_TRANSPARENT_HUGEPAGE can be selected in arch/x86/Kconfig.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:29 +09:00
Minchan Kim ee6f509c32 mm: factor out memory isolate functions
mm/page_alloc.c has some memory isolation functions but they are used only
when we enable CONFIG_{CMA|MEMORY_HOTPLUG|MEMORY_FAILURE}.  So let's make
it configurable by new CONFIG_MEMORY_ISOLATION so that it can reduce
binary size and we can check it simple by CONFIG_MEMORY_ISOLATION, not if
defined CONFIG_{CMA|MEMORY_HOTPLUG|MEMORY_FAILURE}.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:45 -07:00
Linus Torvalds a3fe778c78 Frontswap provides a "transcendent memory" interface for swap pages.
In some environments, dramatic performance savings may be obtained because
 swapped pages are saved in RAM (or a RAM-like device) instead of a swap disk.
 This tag provides the basic infrastructure along with some changes to the
 existing backends.
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Merge tag 'stable/frontswap.v16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm

Pull frontswap feature from Konrad Rzeszutek Wilk:
 "Frontswap provides a "transcendent memory" interface for swap pages.
  In some environments, dramatic performance savings may be obtained
  because swapped pages are saved in RAM (or a RAM-like device) instead
  of a swap disk.  This tag provides the basic infrastructure along with
  some changes to the existing backends."

Fix up trivial conflict in mm/Makefile due to removal of swap token code
changing a line next to the new frontswap entry.

This pull request came in before the merge window even opened, it got
delayed to after the merge window by me just wanting to make sure it had
actual users.  Apparently IBM is using this on their embedded side, and
Jan Beulich says that it's already made available for SLES and OpenSUSE
users.

Also acked by Rik van Riel, and Konrad points to other people liking it
too.  So in it goes.

By Dan Magenheimer (4) and Konrad Rzeszutek Wilk (2)
via Konrad Rzeszutek Wilk
* tag 'stable/frontswap.v16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm:
  frontswap: s/put_page/store/g s/get_page/load
  MAINTAINER: Add myself for the frontswap API
  mm: frontswap: config and doc files
  mm: frontswap: core frontswap functionality
  mm: frontswap: core swap subsystem hooks and headers
  mm: frontswap: add frontswap header file
2012-06-04 12:28:45 -07:00
Christopher Yeoh 5febcbe99d Cross Memory Attach: make it Kconfigurable
Add a Kconfig option to allow people who don't want cross memory attach to
not have it included in their build.

Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-29 16:22:20 -07:00
Michal Nazarewicz 47118af076 mm: mmzone: MIGRATE_CMA migration type added
The MIGRATE_CMA migration type has two main characteristics:
(i) only movable pages can be allocated from MIGRATE_CMA
pageblocks and (ii) page allocator will never change migration
type of MIGRATE_CMA pageblocks.

This guarantees (to some degree) that page in a MIGRATE_CMA page
block can always be migrated somewhere else (unless there's no
memory left in the system).

It is designed to be used for allocating big chunks (eg. 10MiB)
of physically contiguous memory.  Once driver requests
contiguous memory, pages from MIGRATE_CMA pageblocks may be
migrated away to create a contiguous block.

To minimise number of migrations, MIGRATE_CMA migration type
is the last type tried when page allocator falls back to other
migration types when requested.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Rob Clark <rob.clark@linaro.org>
Tested-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Tested-by: Robert Nelson <robertcnelson@gmail.com>
Tested-by: Barry Song <Baohua.Song@csr.com>
2012-05-21 15:09:32 +02:00
Dan Magenheimer 27c6aec214 mm: frontswap: config and doc files
This patch 4of4 adds configuration and documentation files including a FAQ.

[v14: updated docs/FAQ to use zcache and RAMster as examples]
[v10: no change]
[v9: akpm@linux-foundation.org: sysfs->debugfs; no longer need Doc/ABI file]
[v8: rebase to 3.0-rc4]
[v7: rebase to 3.0-rc3]
[v6: rebase to 3.0-rc1]
[v5: change config default to n]
[v4: rebase to 2.6.39]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Acked-by: Jan Beulich <JBeulich@novell.com>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Rik Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-05-15 11:34:03 -04:00
Tejun Heo d4bbf7e775 Merge branch 'master' into x86/memblock
Conflicts & resolutions:

* arch/x86/xen/setup.c

	dc91c728fd "xen: allow extra memory to be in multiple regions"
	24aa07882b "memblock, x86: Replace memblock_x86_reserve/free..."

	conflicted on xen_add_extra_mem() updates.  The resolution is
	trivial as the latter just want to replace
	memblock_x86_reserve_range() with memblock_reserve().

* drivers/pci/intel-iommu.c

	166e9278a3 "x86/ia64: intel-iommu: move to drivers/iommu/"
	5dfe8660a3 "bootmem: Replace work_with_active_regions() with..."

	conflicted as the former moved the file under drivers/iommu/.
	Resolved by applying the chnages from the latter on the moved
	file.

* mm/Kconfig

	6661672053 "memblock: add NO_BOOTMEM config symbol"
	c378ddd53f "memblock, x86: Make ARCH_DISCARD_MEMBLOCK a config option"

	conflicted trivially.  Both added config options.  Just
	letting both add their own options resolves the conflict.

* mm/memblock.c

	d1f0ece6cd "mm/memblock.c: small function definition fixes"
	ed7b56a799 "memblock: Remove memblock_memory_can_coalesce()"

	confliected.  The former updates function removed by the
	latter.  Resolution is trivial.

Signed-off-by: Tejun Heo <tj@kernel.org>
2011-11-28 09:46:22 -08:00
Sam Ravnborg 6661672053 memblock: add NO_BOOTMEM config symbol
With the NO_BOOTMEM symbol added architectures may now use the following
syntax to tell that they do not need bootmem:

	select NO_BOOTMEM

This is much more convinient than adding a new kconfig symbol which was
otherwise required.

Adding this symbol does not conflict with the architctures that already
define their own symbol.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31 17:30:47 -07:00
Tejun Heo c378ddd53f memblock, x86: Make ARCH_DISCARD_MEMBLOCK a config option
From 6839454ae63f1eb21e515c10229ca95c22955fec Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 14 Jul 2011 11:22:17 +0200

Make ARCH_DISCARD_MEMBLOCK a config option so that it can be handled
together with other MEMBLOCK options.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110714094603.GH3455@htj.dyndns.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-14 11:47:52 -07:00
Tejun Heo 7c0caeb866 memblock: Add optional region->nid
From 83103b92f3234ec830852bbc5c45911bd6cbdb20 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 14 Jul 2011 11:22:16 +0200

Add optional region->nid which can be enabled by arch using
CONFIG_HAVE_MEMBLOCK_NODE_MAP.  When enabled, memblock also carries
NUMA node information and replaces early_node_map[].

Newly added memblocks have MAX_NUMNODES as nid.  Arch can then call
memblock_set_node() to set node information.  memblock takes care of
merging and node affine allocations w.r.t. node information.

When MEMBLOCK_NODE_MAP is enabled, early_node_map[], related data
structures and functions to manipulate and iterate it are disabled.
memblock version of __next_mem_pfn_range() is provided such that
for_each_mem_pfn_range() behaves the same and its users don't have to
be updated.

-v2: Yinghai spotted section mismatch caused by missing
     __init_memblock in memblock_set_node().  Fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20110714094342.GF3455@htj.dyndns.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-07-14 11:47:43 -07:00
Michael Witten 140a1ef2f9 mm Kconfig typo: cleancacne -> cleancache
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-06-10 14:47:52 +02:00
Dan Magenheimer 077b1f83a6 mm: cleancache core ops functions and config
This third patch of eight in this cleancache series provides
the core code for cleancache that interfaces between the hooks in
VFS and individual filesystems and a cleancache backend.  It also
includes build and config patches.

Two new files are added: mm/cleancache.c and include/linux/cleancache.h.

Note that CONFIG_CLEANCACHE can default to on; in systems that do
not provide a cleancache backend, all hooks devolve to a simple
check of a global enable flag, so performance impact should
be negligible but can be reduced to zero impact if config'ed off.
However for this first commit, it defaults to off.

Details and a FAQ can be found in Documentation/vm/cleancache.txt

Credits: Cleancache_ops design derived from Jeremy Fitzhardinge
design for tmem

[v8: dan.magenheimer@oracle.com: fix exportfs call affecting btrfs]
[v8: akpm@linux-foundation.org: use static inline function, not macro]
[v7: dan.magenheimer@oracle.com: cleanup sysfs and remove cleancache prefix]
[v6: JBeulich@novell.com: robustly handle buggy fs encode_fh actor definition]
[v5: jeremy@goop.org: clean up global usage and static var names]
[v5: jeremy@goop.org: simplify init hook and any future fs init changes]
[v5: hch@infradead.org: cleaner non-global interface for ops registration]
[v4: adilger@sun.com: interface must support exportfs FS's]
[v4: hch@infradead.org: interface must support 64-bit FS on 32-bit kernel]
[v3: akpm@linux-foundation.org: use one ops struct to avoid pointer hops]
[v3: akpm@linux-foundation.org: document and ensure PageLocked reqts are met]
[v3: ngupta@vflare.org: fix success/fail codes, change funcs to void]
[v2: viro@ZenIV.linux.org.uk: use sane types]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Acked-by: Jan Beulich <JBeulich@novell.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
2011-05-26 10:01:36 -06:00
Andrea Arcangeli 33a938774f mm: compaction: don't depend on HUGETLB_PAGE
Commit 5d6892407 ("thp: select CONFIG_COMPACTION if TRANSPARENT_HUGEPAGE
enabled") causes this warning during the configuration process:

  warning: (TRANSPARENT_HUGEPAGE) selects COMPACTION which has unmet
  direct dependencies (EXPERIMENTAL && HUGETLB_PAGE && MMU)

COMPACTION doesn't depend on HUGETLB_PAGE, it doesn't depend on THP
either, it is also useful for regular alloc_pages(order > 0) including
the very kernel stack during fork (THREAD_ORDER = 1).  It's always
better to enable COMPACTION.

The warning should be an error because we would end up with MIGRATION
not selected, and COMPACTION wouldn't work without migration (despite it
seems to build with an inline migrate_pages returning -ENOSYS).

I'd also like to remove EXPERIMENTAL: compaction has been in the kernel
for some releases (for full safety the default remains disabled which I
think is enough).

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Luca Tettamanti <kronos.it@gmail.com>
Tested-by: Luca Tettamanti <kronos.it@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:02 +10:00
Andrea Arcangeli 5d6892407c thp: select CONFIG_COMPACTION if TRANSPARENT_HUGEPAGE enabled
With transparent hugepage support we need compaction for the "defrag"
sysfs controls to be effective.

At the moment THP hangs the system if COMPACTION isn't selected, as
without COMPACTION lumpy reclaim wouldn't be entirely disabled.  So at the
moment it's not orthogonal.  When lumpy will be removed from the VM I can
remove the select COMPACTION in theory, but then 99% of THP users would be
still doing a mistake in disabling compaction, even if the mistake won't
return in fatal runtime but just slightly degraded performance.  So from a
theoretical standpoing forcing the below select is not needed (the
dependency isn't strict nor at compile time nor at runtime) but from a
practical standpoint it is safer.

If anybody really wants THP to run without compaction, it'd be such a
weird setup that editing the Kconfig file to allow it will be surely not a
problem.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:45 -08:00
Andrea Arcangeli 13ece886d9 thp: transparent hugepage config choice
Allow to choose between the always|madvise default for page faults and
khugepaged at config time.  madvise guarantees zero risk of higher memory
footprint for applications (applications using madvise(MADV_HUGEPAGE)
won't risk to use any more memory by backing their virtual regions with
hugepages).

Initially set the default to N and don't depend on EMBEDDED.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:45 -08:00
Johannes Weiner f2d6bfe9ff thp: add x86 32bit support
Add support for transparent hugepages to x86 32bit.

Share the same VM_ bitflag for VM_MAPPED_COPY.  mm/nommu.c will never
support transparent hugepages.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:44 -08:00
Andrea Arcangeli 4c76d9d1fb thp: CONFIG_TRANSPARENT_HUGEPAGE
Add config option.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:40 -08:00
Linus Torvalds 0fc0531e0a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: update comments to reflect that percpu allocations are always zero-filled
  percpu: Optimize __get_cpu_var()
  x86, percpu: Optimize this_cpu_ptr
  percpu: clear memory allocated with the km allocator
  percpu: fix build breakage on s390 and cleanup build configuration tests
  percpu: use percpu allocator on UP too
  percpu: reduce PCPU_MIN_UNIT_SIZE to 32k
  vmalloc: pcpu_get/free_vm_areas() aren't needed on UP

Fixed up trivial conflicts in include/linux/percpu.h
2010-10-22 17:31:36 -07:00
Andrea Arcangeli 152e0659fc mm: avoid warning when COMPACTION is selected
COMPACTION enables MIGRATION, but MIGRATION spawns a warning if numa or
memhotplug aren't selected.  However MIGRATION doesn't depend on them.  I
guess it's just trying to be strict doing a double check on who's enabling
it, but it doesn't know that compaction also enables MIGRATION.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09 18:57:24 -07:00
Tejun Heo bbddff0545 percpu: use percpu allocator on UP too
On UP, percpu allocations were redirected to kmalloc.  This has the
following problems.

* For certain amount of allocations (determined by
  PERCPU_DYNAMIC_EARLY_SLOTS and PERCPU_DYNAMIC_EARLY_SIZE), percpu
  allocator can be used before the usual kernel memory allocator is
  brought online.  On SMP, this is used to initialize the kernel
  memory allocator.

* percpu allocator honors alignment upto PAGE_SIZE but kmalloc()
  doesn't.  For example, workqueue makes use of larger alignments for
  cpu_workqueues.

Currently, users of percpu allocators need to handle UP differently,
which is somewhat fragile and ugly.  Other than small amount of
memory, there isn't much to lose by enabling percpu allocator on UP.
It can simply use kernel memory based chunk allocation which was added
for SMP archs w/o MMUs.

This patch removes mm/percpu_up.c, builds mm/percpu.c on UP too and
makes UP build use percpu-km.  As percpu addresses and kernel
addresses are always identity mapped and static percpu variables don't
need any special treatment, nothing is arch dependent and mm/percpu.c
implements generic setup_per_cpu_areas() for UP.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-09-08 11:11:23 +02:00
Yinghai Lu 95f72d1ed4 lmb: rename to memblock
via following scripts

      FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

      sed -i \
        -e 's/lmb/memblock/g' \
        -e 's/LMB/MEMBLOCK/g' \
        $FILES

      for N in $(find . -name lmb.[ch]); do
        M=$(echo $N | sed 's/lmb/memblock/g')
        mv $N $M
      done

and remove some wrong change like lmbench and dlmb etc.

also move memblock.c from lib/ to mm/

Suggested-by: Ingo Molnar <mingo@elte.hu>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-14 17:14:00 +10:00
Mel Gorman e9e96b39f9 mm: allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove
CONFIG_MIGRATION currently depends on CONFIG_NUMA or on the architecture
being able to hot-remove memory.  The main users of page migration such as
sys_move_pages(), sys_migrate_pages() and cpuset process migration are
only beneficial on NUMA so it makes sense.

As memory compaction will operate within a zone and is useful on both NUMA
and non-NUMA systems, this patch allows CONFIG_MIGRATION to be set if the
user selects CONFIG_COMPACTION as an option.

[akpm@linux-foundation.org: Depend on CONFIG_HUGETLB_PAGE]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:59 -07:00
Linus Torvalds a626b46e17 Merge branch 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits)
  early_res: Need to save the allocation name in drop_range_partial()
  sparsemem: Fix compilation on PowerPC
  early_res: Add free_early_partial()
  x86: Fix non-bootmem compilation on PowerPC
  core: Move early_res from arch/x86 to kernel/
  x86: Add find_fw_memmap_area
  Move round_up/down to kernel.h
  x86: Make 32bit support NO_BOOTMEM
  early_res: Enhance check_and_double_early_res
  x86: Move back find_e820_area to e820.c
  x86: Add find_early_area_size
  x86: Separate early_res related code from e820.c
  x86: Move bios page reserve early to head32/64.c
  sparsemem: Put mem map for one node together.
  sparsemem: Put usemap for one node together
  x86: Make 64 bit use early_res instead of bootmem before slab
  x86: Only call dma32_reserve_bootmem 64bit !CONFIG_NUMA
  x86: Make early_node_mem get mem > 4 GB if possible
  x86: Dynamically increase early_res array size
  x86: Introduce max_early_res and early_res_count
  ...
2010-03-03 08:15:05 -08:00
Yinghai Lu 9bdac91424 sparsemem: Put mem map for one node together.
Add vmemmap_alloc_block_buf for mem map only.

It will fallback to the old way if it cannot get a block that big.

Before this patch, when a node have 128g ram installed, memmap are
split into two parts or more.
[    0.000000]  [ffffea0000000000-ffffea003fffffff] PMD -> [ffff880100600000-ffff88013e9fffff] on node 1
[    0.000000]  [ffffea0040000000-ffffea006fffffff] PMD -> [ffff88013ec00000-ffff88016ebfffff] on node 1
[    0.000000]  [ffffea0070000000-ffffea007fffffff] PMD -> [ffff882000600000-ffff8820105fffff] on node 0
[    0.000000]  [ffffea0080000000-ffffea00bfffffff] PMD -> [ffff882010800000-ffff8820507fffff] on node 0
[    0.000000]  [ffffea00c0000000-ffffea00dfffffff] PMD -> [ffff882050a00000-ffff8820709fffff] on node 0
[    0.000000]  [ffffea00e0000000-ffffea00ffffffff] PMD -> [ffff884000600000-ffff8840205fffff] on node 2
[    0.000000]  [ffffea0100000000-ffffea013fffffff] PMD -> [ffff884020800000-ffff8840607fffff] on node 2
[    0.000000]  [ffffea0140000000-ffffea014fffffff] PMD -> [ffff884060a00000-ffff8840709fffff] on node 2
[    0.000000]  [ffffea0150000000-ffffea017fffffff] PMD -> [ffff886000600000-ffff8860305fffff] on node 3
[    0.000000]  [ffffea0180000000-ffffea01bfffffff] PMD -> [ffff886030800000-ffff8860707fffff] on node 3
[    0.000000]  [ffffea01c0000000-ffffea01ffffffff] PMD -> [ffff888000600000-ffff8880405fffff] on node 4
[    0.000000]  [ffffea0200000000-ffffea022fffffff] PMD -> [ffff888040800000-ffff8880707fffff] on node 4
[    0.000000]  [ffffea0230000000-ffffea023fffffff] PMD -> [ffff88a000600000-ffff88a0105fffff] on node 5
[    0.000000]  [ffffea0240000000-ffffea027fffffff] PMD -> [ffff88a010800000-ffff88a0507fffff] on node 5
[    0.000000]  [ffffea0280000000-ffffea029fffffff] PMD -> [ffff88a050a00000-ffff88a0709fffff] on node 5
[    0.000000]  [ffffea02a0000000-ffffea02bfffffff] PMD -> [ffff88c000600000-ffff88c0205fffff] on node 6
[    0.000000]  [ffffea02c0000000-ffffea02ffffffff] PMD -> [ffff88c020800000-ffff88c0607fffff] on node 6
[    0.000000]  [ffffea0300000000-ffffea030fffffff] PMD -> [ffff88c060a00000-ffff88c0709fffff] on node 6
[    0.000000]  [ffffea0310000000-ffffea033fffffff] PMD -> [ffff88e000600000-ffff88e0305fffff] on node 7
[    0.000000]  [ffffea0340000000-ffffea037fffffff] PMD -> [ffff88e030800000-ffff88e0707fffff] on node 7

after patch will get
[    0.000000]  [ffffea0000000000-ffffea006fffffff] PMD -> [ffff880100200000-ffff88016e5fffff] on node 0
[    0.000000]  [ffffea0070000000-ffffea00dfffffff] PMD -> [ffff882000200000-ffff8820701fffff] on node 1
[    0.000000]  [ffffea00e0000000-ffffea014fffffff] PMD -> [ffff884000200000-ffff8840701fffff] on node 2
[    0.000000]  [ffffea0150000000-ffffea01bfffffff] PMD -> [ffff886000200000-ffff8860701fffff] on node 3
[    0.000000]  [ffffea01c0000000-ffffea022fffffff] PMD -> [ffff888000200000-ffff8880701fffff] on node 4
[    0.000000]  [ffffea0230000000-ffffea029fffffff] PMD -> [ffff88a000200000-ffff88a0701fffff] on node 5
[    0.000000]  [ffffea02a0000000-ffffea030fffffff] PMD -> [ffff88c000200000-ffff88c0701fffff] on node 6
[    0.000000]  [ffffea0310000000-ffffea037fffffff] PMD -> [ffff88e000200000-ffff88e0701fffff] on node 7

-v2: change buf to vmemmap_buf instead according to Ingo
     also add CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER according to Ingo
-v3: according to Andrew, use sizeof(name) instead of hard coded 15

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-19-git-send-email-yinghai@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-12 09:42:38 -08:00
Paul Mundt 0176bd3dab sh: Drop down to a single quicklist.
We previously had 2 quicklists, one for the PGD case and one for PTEs.
Now that the PGD/PMD cases are handled through slab caches due to the
multi-level configurability, only the PTE quicklist remains. As such,
reduce NR_QUICK to its appropriate size and bump down the PTE quicklist
index.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-05 12:35:00 +09:00
Andi Kleen 27df5068e2 HWPOISON: Add PROC_FS dependency to hwpoison injector v2
The injector filter requires stable_page_flags() which is supplied
by procfs. So make it dependent on that.

Also add ifdefs around the filter code in memory-failure.c so that
when the filter is disabled due to missing dependencies the whole
code still builds.

Reported-by: Ingo Molnar
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-21 19:56:42 +01:00
David Howells 6e14154676 NOMMU: Optimise away the {dac_,}mmap_min_addr tests
In NOMMU mode clamp dac_mmap_min_addr to zero to cause the tests on it to be
skipped by the compiler.  We do this as the minimum mmap address doesn't make
any sense in NOMMU mode.

mmap_min_addr and round_hint_to_min() can be discarded entirely in NOMMU mode.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-12-17 09:25:19 +11:00
Andi Kleen 413f9efbc5 HWPOISON: mention HWPoison in Kconfig entry
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:20:00 +01:00
Wu Fengguang 478c5ffc0b HWPOISON: add page flags filter
When specified, only poison pages if ((page_flags & mask) == value).

-       corrupt-filter-flags-mask
-       corrupt-filter-flags-value

This allows stress testing of many kinds of pages.

Strictly speaking, the buddy pages requires taking zone lock, to avoid
setting PG_hwpoison on a "was buddy but now allocated to someone" page.
However we can just do nothing because we set PG_locked in the beginning,
this prevents the page allocator from allocating it to someone. (It will
BUG() on the unexpected PG_locked, which is fine for hwpoison testing.)

[AK: Add select PROC_PAGE_MONITOR to satisfy dependency]

CC: Nick Piggin <npiggin@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-16 12:19:59 +01:00
Hugh Dickins d0f209f68f ksm: remove unswappable max_kernel_pages
Now that ksm pages are swappable, and the known holes plugged, remove
mention of unswappable kernel pages from KSM documentation and comments.

Remove the totalram_pages/4 initialization of max_kernel_pages.  In fact,
remove max_kernel_pages altogether - we can reinstate it if removal turns
out to break someone's script; but if we later want to limit KSM's memory
usage, limiting the stable nodes would not be an effective approach.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Chris Wright <chrisw@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:20 -08:00
Hugh Dickins a70caa8ba4 mm: stop ptlock enlarging struct page
CONFIG_DEBUG_SPINLOCK adds 12 or 16 bytes to a 32- or 64-bit spinlock_t,
and CONFIG_DEBUG_LOCK_ALLOC adds another 12 or 24 bytes to it: lockdep
enables both of those, and CONFIG_LOCK_STAT adds 8 or 16 bytes to that.

When 2.6.15 placed the split page table lock inside struct page (usually
sized 32 or 56 bytes), only CONFIG_DEBUG_SPINLOCK was a possibility, and
we ignored the enlargement (but fitted in CONFIG_GENERIC_LOCKBREAK's 4 by
letting the spinlock_t occupy both page->private and page->mapping).

Should these debugging options be allowed to double the size of a struct
page, when only one minority use of the page (as a page table) needs to
fit a spinlock in there?  Perhaps not.

Take the easy way out: switch off SPLIT_PTLOCK_CPUS when DEBUG_SPINLOCK or
DEBUG_LOCK_ALLOC is in force.  I've sometimes tried to be cleverer,
kmallocing a cacheline for the spinlock when it doesn't fit, but given up
each time.  Falling back to mm->page_table_lock (as we do when ptlock is
not split) lets lockdep check out the strictest path anyway.

And now that some arches allow 8192 cpus, use 999999 for infinity.

(What has this got to do with KSM swapping?  It doesn't care about the
size of struct page, but may care about random junk in page->mapping - to
be explained separately later.)

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:17 -08:00
Hugh Dickins af8e3354b4 mm: CONFIG_MMU for PG_mlocked
Remove three degrees of obfuscation, left over from when we had
CONFIG_UNEVICTABLE_LRU.  MLOCK_PAGES is CONFIG_HAVE_MLOCKED_PAGE_BIT is
CONFIG_HAVE_MLOCK is CONFIG_MMU.  rmap.o (and memory-failure.o) are only
built when CONFIG_MMU, so don't need such conditions at all.

Somehow, I feel no compulsion to remove the CONFIG_HAVE_MLOCK* lines from
169 defconfigs: leave those to evolve in due course.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15 08:53:17 -08:00
Andi Kleen 6ad696d2cf mm: allow memory hotplug and hibernation in the same kernel
Allow memory hotplug and hibernation in the same kernel

Memory hotplug and hibernation were exclusive in Kconfig.  This is
obviously a problem for distribution kernels who want to support both in
the same image.

After some discussions with Rafael and others the only problem is with
parallel memory hotadd or removal while a hibernation operation is in
process.  It was also working for s390 before.

This patch removes the Kconfig level exclusion, and simply makes the
memory add / remove functions grab the pm_mutex to exclude against
hibernation.

Fixes a regression - old kernels didn't exclude memory hotadd and
hibernation.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-17 17:40:33 -08:00
Linus Torvalds 0a53f1693c Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/ppc64: Use preempt_schedule_irq instead of preempt_schedule
  powerpc: Minor cleanup to lib/Kconfig.debug
  powerpc: Minor cleanup to sound/ppc/Kconfig
  powerpc: Minor cleanup to init/Kconfig
  powerpc: Limit memory hotplug support to PPC64 Book-3S machines
  powerpc: Limit hugetlbfs support to PPC64 Book-3S machines
  powerpc: Fix compile errors found by new ppc64e_defconfig
  powerpc: Add a Book-3E 64-bit defconfig
  powerpc/booke: Fix xmon single step on PowerPC Book-E
  powerpc: Align vDSO base address
  powerpc: Fix segment mapping in vdso32
  powerpc/iseries: Remove compiler version dependent hack
  powerpc/perf_events: Fix priority of MSR HV vs PR bits
  powerpc/5200: Update defconfigs
  drivers/serial/mpc52xx_uart.c: Use UPIO_MEM rather than SERIAL_IO_MEM
  powerpc/boot/dts: drop obsolete 'fsl5200-clocking'
  of: Remove nested function
  mpc5200: support for the MAN mpc5200 based board mucmc52
  mpc5200: support for the MAN mpc5200 based board uc101
2009-10-29 08:59:06 -07:00
Russell King 1a83e175dc mm: fix sparsemem configuration
Currently, sparsemem is only available if EXPERIMENTAL is enabled.
However, it hasn't ever been marked experimental.

It's been about four years since sparsemem was merged, and we have
platforms which depend on it; allow architectures to decide whether
sparsemem should be the default memory model.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-29 07:39:31 -07:00
Kumar Gala ed84a07a12 powerpc: Limit memory hotplug support to PPC64 Book-3S machines
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-27 16:42:41 +11:00
Hugh Dickins c73602ad31 ksm: more on default values
Adjust the max_kernel_pages default to a quarter of totalram_pages,
instead of nr_free_buffer_pages() / 4: the KSM pages themselves come from
highmem, and even on a 16GB PAE machine, 4GB of KSM pages would only be
pinning 32MB of lowmem with their rmap_items, so no need for the more
obscure calculation (nor for its own special init function).

There is no way for the user to switch KSM on if CONFIG_SYSFS is not
enabled, so in that case default run to KSM_RUN_MERGE.

Update KSM Documentation and Kconfig to reflect the new defaults.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-08 07:36:38 -07:00
Linus Torvalds d949f36f18 x86: Fix hwpoison code related build failure on 32-bit NUMAQ
This build failure triggers:

 In file included from include/linux/suspend.h:8,
                 from arch/x86/kernel/asm-offsets_32.c:11,
                 from arch/x86/kernel/asm-offsets.c:2:
 include/linux/mm.h:503:2: error: #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS

Because due to the hwpoison page flag we ran out of page
flags on 32-bit.

Dont turn on hwpoison on 32-bit NUMA (it's rare in any
case).

Also clean up the Kconfig dependencies in the generic MM
code by introducing ARCH_SUPPORTS_MEMORY_FAILURE.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-27 09:55:11 +02:00
Linus Torvalds db16826367 Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6
* 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits)
  HWPOISON: Enable error_remove_page on btrfs
  HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
  HWPOISON: Add madvise() based injector for hardware poisoned pages v4
  HWPOISON: Enable error_remove_page for NFS
  HWPOISON: Enable .remove_error_page for migration aware file systems
  HWPOISON: The high level memory error handler in the VM v7
  HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process
  HWPOISON: shmem: call set_page_dirty() with locked page
  HWPOISON: Define a new error_remove_page address space op for async truncation
  HWPOISON: Add invalidate_inode_page
  HWPOISON: Refactor truncate to allow direct truncating of page v2
  HWPOISON: check and isolate corrupted free pages v2
  HWPOISON: Handle hardware poisoned pages in try_to_unmap
  HWPOISON: Use bitmask/action code for try_to_unmap behaviour
  HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2
  HWPOISON: Add poison check to page fault handling
  HWPOISON: Add basic support for poisoned pages in fault handler v3
  HWPOISON: Add new SIGBUS error codes for hardware poison signals
  HWPOISON: Add support for poison swap entries v2
  HWPOISON: Export some rmap vma locking to outside world
  ...
2009-09-24 07:53:22 -07:00
Hugh Dickins 7701c9c0f5 ksm: add some documentation
Add Documentation/vm/ksm.txt: how to use the Kernel Samepage Merging feature

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:33 -07:00
Hugh Dickins f8af4da3b4 ksm: the mm interface to ksm
This patch presents the mm interface to a dummy version of ksm.c, for
better scrutiny of that interface: the real ksm.c follows later.

When CONFIG_KSM is not set, madvise(2) reject MADV_MERGEABLE and
MADV_UNMERGEABLE with EINVAL, since that seems more helpful than
pretending that they can be serviced.  But when CONFIG_KSM=y, accept them
even if KSM is not currently running, and even on areas which KSM will not
touch (e.g.  hugetlb or shared file or special driver mappings).

Like other madvices, report ENOMEM despite success if any area in the
range is unmapped, and use EAGAIN to report out of memory.

Define vma flag VM_MERGEABLE to identify an area on which KSM may try
merging pages: leave it to ksm_madvise() to decide whether to set it.
Define mm flag MMF_VM_MERGEABLE to identify an mm which might contain
VM_MERGEABLE areas, to minimize callouts when forking or exiting.

Based upon earlier patches by Chris Wright and Izik Eidus.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Izik Eidus <ieidus@redhat.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:31 -07:00
Andi Kleen cae681fc12 HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs
Useful for some testing scenarios, although specific testing is often
done better through MADV_POISON

This can be done with the x86 level MCE injector too, but this interface
allows it to do independently from low level x86 changes.

v2: Add module license (Haicheng Li)

Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:17 +02:00
Andi Kleen 6a46079cf5 HWPOISON: The high level memory error handler in the VM v7
Add the high level memory handler that poisons pages
that got corrupted by hardware (typically by a two bit flip in a DIMM
or a cache) on the Linux level. The goal is to prevent everyone
from accessing these pages in the future.

This done at the VM level by marking a page hwpoisoned
and doing the appropriate action based on the type of page
it is.

The code that does this is portable and lives in mm/memory-failure.c

To quote the overview comment:

High level machine check handler. Handles pages reported by the
hardware as being corrupted usually due to a 2bit ECC memory or cache
failure.

This focuses on pages detected as corrupted in the background.
When the current CPU tries to consume corruption the currently
running process can just be killed directly instead. This implies
that if the error cannot be handled for some reason it's safe to
just ignore it because no corruption has been consumed yet. Instead
when that happens another machine check will happen.

Handles page cache pages in various states. The tricky part
here is that we can access any page asynchronous to other VM
users, because memory failures could happen anytime and anywhere,
possibly violating some of their assumptions. This is why this code
has to be extremely careful. Generally it tries to use normal locking
rules, as in get the standard locks, even if that means the
error handling takes potentially a long time.

Some of the operations here are somewhat inefficient and have non
linear algorithmic complexity, because the data structures have not
been optimized for this case. This is in particular the case
for the mapping from a vma to a process. Since this case is expected
to be rare we hope we can get away with this.

There are in principle two strategies to kill processes on poison:
- just unmap the data and wait for an actual reference before
killing
- kill as soon as corruption is detected.
Both have advantages and disadvantages and should be used
in different situations. Right now both are implemented and can
be switched with a new sysctl vm.memory_failure_early_kill
The default is early kill.

The patch does some rmap data structure walking on its own to collect
processes to kill. This is unusual because normally all rmap data structure
knowledge is in rmap.c only. I put it here for now to keep
everything together and rmap knowledge has been seeping out anyways

Includes contributions from Johannes Weiner, Chris Mason, Fengguang Wu,
Nick Piggin (who did a lot of great work) and others.

Cc: npiggin@suse.de
Cc: riel@redhat.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
2009-09-16 11:50:15 +02:00
Linus Torvalds 227423904c Merge branch 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, pat: Fix cacheflush address in change_page_attr_set_clr()
  mm: remove !NUMA condition from PAGEFLAGS_EXTENDED condition set
  x86: Fix earlyprintk=dbgp for machines without NX
  x86, pat: Sanity check remap_pfn_range for RAM region
  x86, pat: Lookup the protection from memtype list on vm_insert_pfn()
  x86, pat: Add lookup_memtype to get the current memtype of a paddr
  x86, pat: Use page flags to track memtypes of RAM pages
  x86, pat: Generalize the use of page flag PG_uncached
  x86, pat: Add rbtree to do quick lookup in memtype tracking
  x86, pat: Add PAT reserve free to io_mapping* APIs
  x86, pat: New i/f for driver to request memtype for IO regions
  x86, pat: ioremap to follow same PAT restrictions as other PAT users
  x86, pat: Keep identity maps consistent with mmaps even when pat_disabled
  x86, mtrr: make mtrr_aps_delayed_init static bool
  x86, pat/mtrr: Rendezvous all the cpus for MTRR/PAT init
  generic-ipi: Allow cpus not yet online to call smp_call_function with irqs disabled
  x86: Fix an incorrect argument of reserve_bootmem()
  x86: Fix system crash when loading with "reservetop" parameter
2009-09-15 09:19:38 -07:00
H. Peter Anvin a269cca992 mm: remove !NUMA condition from PAGEFLAGS_EXTENDED condition set
CONFIG_PAGEFLAGS_EXTENDED disables a trick to conserve pageflags.
This trick is indended to be enabled when the pressure on page flags
is very high.

The previous condition was:

-       depends on 64BIT || SPARSEMEM_VMEMMAP || !NUMA || !SPARSEMEM

... however, the sparsemem code already has a way to crowd out the
node number from the pageflags, which means that !NUMA actually
doesn't contribute to hard pageflags exhaustion.

This is required for the new PG_uncached flag to not cause pageflags
exhaustion on x86_32 + PAE + SPARSEMEM + !NUMA.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <4A9828F4.4040905@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Suresh Siddha <suresh.siddha@intel.com>
2009-08-31 11:17:44 -07:00
Eric Paris 788084aba2 Security/SELinux: seperate lsm specific mmap_min_addr
Currently SELinux enforcement of controls on the ability to map low memory
is determined by the mmap_min_addr tunable.  This patch causes SELinux to
ignore the tunable and instead use a seperate Kconfig option specific to how
much space the LSM should protect.

The tunable will now only control the need for CAP_SYS_RAWIO and SELinux
permissions will always protect the amount of low memory designated by
CONFIG_LSM_MMAP_MIN_ADDR.

This allows users who need to disable the mmap_min_addr controls (usual reason
being they run WINE as a non-root user) to do so and still have SELinux
controls preventing confined domains (like a web server) from being able to
map some area of low memory.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-17 15:09:11 +10:00
Linus Torvalds 517d08699b Merge branch 'akpm'
* akpm: (182 commits)
  fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
  fbdev: *bfin*: fix __dev{init,exit} markings
  fbdev: *bfin*: drop unnecessary calls to memset
  fbdev: bfin-t350mcqb-fb: drop unused local variables
  fbdev: blackfin has __raw I/O accessors, so use them in fb.h
  fbdev: s1d13xxxfb: add accelerated bitblt functions
  tcx: use standard fields for framebuffer physical address and length
  fbdev: add support for handoff from firmware to hw framebuffers
  intelfb: fix a bug when changing video timing
  fbdev: use framebuffer_release() for freeing fb_info structures
  radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
  s3c-fb: CPUFREQ frequency scaling support
  s3c-fb: fix resource releasing on error during probing
  carminefb: fix possible access beyond end of carmine_modedb[]
  acornfb: remove fb_mmap function
  mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
  mb862xxfb: restrict compliation of platform driver to PPC
  Samsung SoC Framebuffer driver: add Alpha Channel support
  atmel-lcdc: fix pixclock upper bound detection
  offb: use framebuffer_alloc() to allocate fb_info struct
  ...

Manually fix up conflicts due to kmemcheck in mm/slab.c
2009-06-16 19:50:13 -07:00
KOSAKI Motohiro 6837765963 mm: remove CONFIG_UNEVICTABLE_LRU config option
Currently, nobody wants to turn UNEVICTABLE_LRU off.  Thus this
configurability is unnecessary.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:42 -07:00
Gerald Schaefer 0399790498 [S390] pm: memory hotplug power management callbacks
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-16 10:31:20 +02:00
Christoph Lameter e0a94c2a63 security: use mmap_min_addr indepedently of security models
This patch removes the dependency of mmap_min_addr on CONFIG_SECURITY.
It also sets a default mmap_min_addr of 4096.

mmapping of addresses below 4096 will only be possible for processes
with CAP_SYS_RAWIO.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Eric Paris <eparis@redhat.com>
Looks-ok-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
2009-06-04 12:07:48 +10:00
David Howells fc4d5c292b nommu: make the initial mmap allocation excess behaviour Kconfig configurable
NOMMU mmap() has an option controlled by a sysctl variable that determines
whether the allocations made by do_mmap_private() should have the excess
space trimmed off and returned to the allocator.  Make the initial setting
of this variable a Kconfig configuration option.

The reason there can be excess space is that the allocator only allocates
in power-of-2 size chunks, but mmap()'s can be made in sizes that aren't a
power of 2.

There are two alternatives:

 (1) Keep the excess as dead space.  The dead space then remains unused for the
     lifetime of the mapping.  Mappings of shared objects such as libc, ld.so
     or busybox's text segment may retain their dead space forever.

 (2) Return the excess to the allocator.  This means that the dead space is
     limited to less than a page per mapping, but it means that for a transient
     process, there's more chance of fragmentation as the excess space may be
     reused fairly quickly.

During the boot process, a lot of transient processes are created, and
this can cause a lot of fragmentation as the pagecache and various slabs
grow greatly during this time.

By turning off the trimming of excess space during boot and disabling
batching of frees, Coldfire can manage to boot.

A better way of doing things might be to have /sbin/init turn this option
off.  By that point libc, ld.so and init - which are all long-duration
processes - have all been loaded and trimmed.

Reported-by: Lanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Lanttor Guo <lanttor.guo@freescale.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06 16:36:10 -07:00
David Howells 5a52edded3 mm: point the UNEVICTABLE_LRU config option at the documentation
Point the UNEVICTABLE_LRU config option at the documentation describing
the option.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-13 15:04:31 -07:00
David Howells 71aa653c6b nommu: make CONFIG_UNEVICTABLE_LRU available when CONFIG_MMU=n
Make CONFIG_UNEVICTABLE_LRU available when CONFIG_MMU=n.  There's no logical
reason it shouldn't be available, and it can be used for ramfs.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Enrik Berkhan <Enrik.Berkhan@ge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:15 -07:00
David Howells 33925b25d2 nommu: there is no mlock() for NOMMU, so don't provide the bits
The mlock() facility does not exist for NOMMU since all mappings are
effectively locked anyway, so we don't make the bits available when
they're not useful.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Enrik Berkhan <Enrik.Berkhan@ge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:14 -07:00
Geert Uytterhoeven 67faaada1e Remove obsolete CONFIG_RESOURCES_64BIT
commit 8308c54d7e ("generic: redefine
resource_size_t as phys_addr_t") made CONFIG_RESOURCES_64BIT obsolete, but
didn't remove it. Remove it.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:14 -08:00
Lee Schermerhorn 894bc31041 Unevictable LRU Infrastructure
When the system contains lots of mlocked or otherwise unevictable pages,
the pageout code (kswapd) can spend lots of time scanning over these
pages.  Worse still, the presence of lots of unevictable pages can confuse
kswapd into thinking that more aggressive pageout modes are required,
resulting in all kinds of bad behaviour.

Infrastructure to manage pages excluded from reclaim--i.e., hidden from
vmscan.  Based on a patch by Larry Woodman of Red Hat.  Reworked to
maintain "unevictable" pages on a separate per-zone LRU list, to "hide"
them from vmscan.

Kosaki Motohiro added the support for the memory controller unevictable
lru list.

Pages on the unevictable list have both PG_unevictable and PG_lru set.
Thus, PG_unevictable is analogous to and mutually exclusive with
PG_active--it specifies which LRU list the page is on.

The unevictable infrastructure is enabled by a new mm Kconfig option
[CONFIG_]UNEVICTABLE_LRU.

A new function 'page_evictable(page, vma)' in vmscan.c tests whether or
not a page may be evictable.  Subsequent patches will add the various
!evictable tests.  We'll want to keep these tests light-weight for use in
shrink_active_list() and, possibly, the fault path.

To avoid races between tasks putting pages [back] onto an LRU list and
tasks that might be moving the page from non-evictable to evictable state,
the new function 'putback_lru_page()' -- inverse to 'isolate_lru_page()'
-- tests the "evictability" of a page after placing it on the LRU, before
dropping the reference.  If the page has become unevictable,
putback_lru_page() will redo the 'putback', thus moving the page to the
unevictable list.  This way, we avoid "stranding" evictable pages on the
unevictable list.

[akpm@linux-foundation.org: fix fallout from out-of-order merge]
[riel@redhat.com: fix UNEVICTABLE_LRU and !PROC_PAGE_MONITOR build]
[nishimura@mxp.nes.nec.co.jp: remove redundant mapping check]
[kosaki.motohiro@jp.fujitsu.com: unevictable-lru-infrastructure: putback_lru_page()/unevictable page handling rework]
[kosaki.motohiro@jp.fujitsu.com: kill unnecessary lock_page() in vmscan.c]
[kosaki.motohiro@jp.fujitsu.com: revert migration change of unevictable lru infrastructure]
[kosaki.motohiro@jp.fujitsu.com: revert to unevictable-lru-infrastructure-kconfig-fix.patch]
[kosaki.motohiro@jp.fujitsu.com: restore patch failure of vmstat-unevictable-and-mlocked-pages-vm-events.patch]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Debugged-by: Benjamin Kidwell <benjkidwell@yahoo.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:50:26 -07:00
Linus Torvalds e533b22705 Merge branch 'core-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  do_generic_file_read: s/EINTR/EIO/ if lock_page_killable() fails
  softirq, warning fix: correct a format to avoid a warning
  softirqs, debug: preemption check
  x86, pci-hotplug, calgary / rio: fix EBDA ioremap()
  IO resources, x86: ioremap sanity check to catch mapping requests exceeding, fix
  IO resources, x86: ioremap sanity check to catch mapping requests exceeding the BAR sizes
  softlockup: Documentation/sysctl/kernel.txt: fix softlockup_thresh description
  dmi scan: warn about too early calls to dmi_check_system()
  generic: redefine resource_size_t as phys_addr_t
  generic: make PFN_PHYS explicitly return phys_addr_t
  generic: add phys_addr_t for holding physical addresses
  softirq: allocate less vectors
  IO resources: fix/remove printk
  printk: robustify printk, update comment
  printk: robustify printk, fix #2
  printk: robustify printk, fix
  printk: robustify printk

Fixed up conflicts in:
	arch/powerpc/include/asm/types.h
	arch/powerpc/platforms/Kconfig.cputype
manually.
2008-10-16 15:17:40 -07:00
Jan Beulich 9ba16087d9 Kconfig: eliminate "def_bool n" constructs
Using "def_bool n" is pointless, simply using bool here appears more
appropriate.

Further, retaining such options that don't have a prompt and aren't
selected by anything seems also at least questionable.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:31 -07:00
Jeremy Fitzhardinge 600715dcdf generic: add phys_addr_t for holding physical addresses
Add a kernel-wide "phys_addr_t" which is guaranteed to be able to hold
any physical address.  By default it equals the word size of the
architecture, but a 32-bit architecture can set ARCH_PHYS_ADDR_T_64BIT
if it needs a 64-bit phys_addr_t.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 17:24:25 +02:00
Rusty Russell 912985dce4 mm: Make generic weak get_user_pages_fast and EXPORT_GPL it
Out of line get_user_pages_fast fallback implementation, make it a weak
symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST.

Export the symbol to modules so lguest can use it.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-12 17:52:53 +10:00
Andrea Arcangeli cddb8a5c14 mmu-notifiers: core
With KVM/GFP/XPMEM there isn't just the primary CPU MMU pointing to pages.
 There are secondary MMUs (with secondary sptes and secondary tlbs) too.
sptes in the kvm case are shadow pagetables, but when I say spte in
mmu-notifier context, I mean "secondary pte".  In GRU case there's no
actual secondary pte and there's only a secondary tlb because the GRU
secondary MMU has no knowledge about sptes and every secondary tlb miss
event in the MMU always generates a page fault that has to be resolved by
the CPU (this is not the case of KVM where the a secondary tlb miss will
walk sptes in hardware and it will refill the secondary tlb transparently
to software if the corresponding spte is present).  The same way
zap_page_range has to invalidate the pte before freeing the page, the spte
(and secondary tlb) must also be invalidated before any page is freed and
reused.

Currently we take a page_count pin on every page mapped by sptes, but that
means the pages can't be swapped whenever they're mapped by any spte
because they're part of the guest working set.  Furthermore a spte unmap
event can immediately lead to a page to be freed when the pin is released
(so requiring the same complex and relatively slow tlb_gather smp safe
logic we have in zap_page_range and that can be avoided completely if the
spte unmap event doesn't require an unpin of the page previously mapped in
the secondary MMU).

The mmu notifiers allow kvm/GRU/XPMEM to attach to the tsk->mm and know
when the VM is swapping or freeing or doing anything on the primary MMU so
that the secondary MMU code can drop sptes before the pages are freed,
avoiding all page pinning and allowing 100% reliable swapping of guest
physical address space.  Furthermore it avoids the code that teardown the
mappings of the secondary MMU, to implement a logic like tlb_gather in
zap_page_range that would require many IPI to flush other cpu tlbs, for
each fixed number of spte unmapped.

To make an example: if what happens on the primary MMU is a protection
downgrade (from writeable to wrprotect) the secondary MMU mappings will be
invalidated, and the next secondary-mmu-page-fault will call
get_user_pages and trigger a do_wp_page through get_user_pages if it
called get_user_pages with write=1, and it'll re-establishing an updated
spte or secondary-tlb-mapping on the copied page.  Or it will setup a
readonly spte or readonly tlb mapping if it's a guest-read, if it calls
get_user_pages with write=0.  This is just an example.

This allows to map any page pointed by any pte (and in turn visible in the
primary CPU MMU), into a secondary MMU (be it a pure tlb like GRU, or an
full MMU with both sptes and secondary-tlb like the shadow-pagetable layer
with kvm), or a remote DMA in software like XPMEM (hence needing of
schedule in XPMEM code to send the invalidate to the remote node, while no
need to schedule in kvm/gru as it's an immediate event like invalidating
primary-mmu pte).

At least for KVM without this patch it's impossible to swap guests
reliably.  And having this feature and removing the page pin allows
several other optimizations that simplify life considerably.

Dependencies:

1) mm_take_all_locks() to register the mmu notifier when the whole VM
   isn't doing anything with "mm".  This allows mmu notifier users to keep
   track if the VM is in the middle of the invalidate_range_begin/end
   critical section with an atomic counter incraese in range_begin and
   decreased in range_end.  No secondary MMU page fault is allowed to map
   any spte or secondary tlb reference, while the VM is in the middle of
   range_begin/end as any page returned by get_user_pages in that critical
   section could later immediately be freed without any further
   ->invalidate_page notification (invalidate_range_begin/end works on
   ranges and ->invalidate_page isn't called immediately before freeing
   the page).  To stop all page freeing and pagetable overwrites the
   mmap_sem must be taken in write mode and all other anon_vma/i_mmap
   locks must be taken too.

2) It'd be a waste to add branches in the VM if nobody could possibly
   run KVM/GRU/XPMEM on the kernel, so mmu notifiers will only enabled if
   CONFIG_KVM=m/y.  In the current kernel kvm won't yet take advantage of
   mmu notifiers, but this already allows to compile a KVM external module
   against a kernel with mmu notifiers enabled and from the next pull from
   kvm.git we'll start using them.  And GRU/XPMEM will also be able to
   continue the development by enabling KVM=m in their config, until they
   submit all GRU/XPMEM GPLv2 code to the mainline kernel.  Then they can
   also enable MMU_NOTIFIERS in the same way KVM does it (even if KVM=n).
   This guarantees nobody selects MMU_NOTIFIER=y if KVM and GRU and XPMEM
   are all =n.

The mmu_notifier_register call can fail because mm_take_all_locks may be
interrupted by a signal and return -EINTR.  Because mmu_notifier_reigster
is used when a driver startup, a failure can be gracefully handled.  Here
an example of the change applied to kvm to register the mmu notifiers.
Usually when a driver startups other allocations are required anyway and
-ENOMEM failure paths exists already.

 struct  kvm *kvm_arch_create_vm(void)
 {
        struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
+       int err;

        if (!kvm)
                return ERR_PTR(-ENOMEM);

        INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);

+       kvm->arch.mmu_notifier.ops = &kvm_mmu_notifier_ops;
+       err = mmu_notifier_register(&kvm->arch.mmu_notifier, current->mm);
+       if (err) {
+               kfree(kvm);
+               return ERR_PTR(err);
+       }
+
        return kvm;
 }

mmu_notifier_unregister returns void and it's reliable.

The patch also adds a few needed but missing includes that would prevent
kernel to compile after these changes on non-x86 archs (x86 didn't need
them by luck).

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix mm/filemap_xip.c build]
[akpm@linux-foundation.org: fix mm/mmu_notifier.c build]
Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Kanoj Sarcar <kanojsarcar@yahoo.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Avi Kivity <avi@qumranet.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Chris Wright <chrisw@redhat.com>
Cc: Marcelo Tosatti <marcelo@kvack.org>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Izik Eidus <izike@qumranet.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28 16:30:21 -07:00
Nick Piggin 8174c430e4 x86: lockless get_user_pages_fast()
Implement get_user_pages_fast without locking in the fastpath on x86.

Do an optimistic lockless pagetable walk, without taking mmap_sem or any
page table locks or even mmap_sem.  Page table existence is guaranteed by
turning interrupts off (combined with the fact that we're always looking
up the current mm, means we can do the lockless page table walk within the
constraints of the TLB shootdown design).  Basically we can do this
lockless pagetable walk in a similar manner to the way the CPU's pagetable
walker does not have to take any locks to find present ptes.

This patch (combined with the subsequent ones to convert direct IO to use
it) was found to give about 10% performance improvement on a 2 socket 8
core Intel Xeon system running an OLTP workload on DB2 v9.5

 "To test the effects of the patch, an OLTP workload was run on an IBM
  x3850 M2 server with 2 processors (quad-core Intel Xeon processors at
  2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel.  Comparing
  runs with and without the patch resulted in an overall performance
  benefit of ~9.8%.  Correspondingly, oprofiles showed that samples from
  __up_read and __down_read routines that is seen during thread contention
  for system resources was reduced from 2.8% down to .05%.  Monitoring the
  /proc/vmstat output from the patched run showed that the counter for
  fast_gup contained a very high number while the fast_gup_slow value was
  zero."

(fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a
counter we had for the number of times the slowpath was invoked).

The main reason for the improvement is that DB2 has multiple threads each
issuing direct-IO.  Direct-IO uses get_user_pages, and thus the threads
contend the mmap_sem cacheline, and can also contend on page table locks.

I would anticipate larger performance gains on larger systems, however I
think DB2 uses an adaptive mix of threads and processes, so it could be
that thread contention remains pretty constant as machine size increases.
In which case, we stuck with "only" a 10% gain.

The downside of using get_user_pages_fast is that if there is not a pte
with the correct permissions for the access, we end up falling back to
get_user_pages and so the get_user_pages_fast is a bit of extra work.
However this should not be the common case in most performance critical
code.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: Kconfig fix]
[akpm@linux-foundation.org: Makefile fix/cleanup]
[akpm@linux-foundation.org: warning fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:06 -07:00
Gerald Schaefer 83d1674a94 mm: make CONFIG_MIGRATION available w/o CONFIG_NUMA
We'd like to support CONFIG_MEMORY_HOTREMOVE on s390, which depends on
CONFIG_MIGRATION.  So far, CONFIG_MIGRATION is only available with NUMA
support.

This patch makes CONFIG_MIGRATION selectable for architectures that define
ARCH_ENABLE_MEMORY_HOTREMOVE.  When MIGRATION is enabled w/o NUMA, the
kernel won't compile because migrate_vmas() does not know about
vm_ops->migrate() and vma_migratable() does not know about policy_zone.
To fix this, those two functions can be restricted to '#ifdef CONFIG_NUMA'
because they are not being used w/o NUMA.  vma_migratable() is moved over
from migrate.h to mempolicy.h.

[kosaki.motohiro@jp.fujitsu.com: build fix]
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: KOSAKI Motorhiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:21 -07:00
Linus Torvalds 6c118e43dc Merge git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6: (31 commits)
  avr32: Fix typo of IFSR in a comment in the PIO header file
  avr32: Power Management support ("standby" and "mem" modes)
  avr32: Add system device for the internal interrupt controller (intc)
  avr32: Add simple SRAM allocator
  avr32: Enable SDRAMC clock at startup
  rtc-at32ap700x: Enable wakeup
  macb: Basic suspend/resume support
  atmel_serial: Drain console TX shifter before suspending
  atmel_serial: Fix build on avr32 with CONFIG_PM enabled
  avr32: Use a quicklist for PTE allocation as well
  avr32: Use a quicklist for PGD allocation
  avr32: Cover the kernel page tables in the user PGDs
  avr32: Store virtual addresses in the PGD
  avr32: Remove useless zeroing of swapper_pg_dir at startup
  avr32: Clean up and optimize the TLB operations
  avr32: Rename at32ap.c -> pdc.c
  avr32: Move setup_platform() into chip-specific file
  avr32: Kill special exception handler sections
  avr32: Kill unneeded #include <asm/pgalloc.h> from asm/mmu_context.h
  avr32: Clean up time.c #includes
  ...
2008-07-14 13:37:29 -07:00
Heiko Carstens 421c175c4d [S390] Add support for memory hot-add.
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14 10:02:16 +02:00
Haavard Skinnemoen 38510754a5 avr32: Use a quicklist for PTE allocation as well
Using a quicklist to allocate PTEs might be slightly faster than using
the page allocator directly since we might avoid zeroing the page
after each allocation.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:29 +02:00
Christoph Lameter e20b8cca76 PAGEFLAGS_EXTENDED and separate page flags for Head and Tail
Having separate page flags for the head and the tail of a compound page allows
the compiler to use bitops instead of operations on a word to check for a tail
page.  That is f.e.  important for virt_to_head_page() which is used in
various critical code paths (kfree for example):

Code for PageTail(page)

Before:

 mov    (%rdi),%rdx		page->flags
 mov    %rdx,%rax		3 bytes
 and    $0x12000,%eax		5 bytes
 cmp    $0x12000,%rax		6 bytes
 je     897 <kfree+0xa7>

After:

 mov    (%rdi),%rax
 test   $0x40,%ah			(3 bytes)
 jne    887 <kfree+0x97>

So we go from 14 bytes to 3 bytes and from 3 instructions to one.  From the
use of 2 registers we go to none.

We can only use page flags for this if we have page flags available.  This
patch introduces CONFIG_PAGEFLAGS_EXTENDED that is set if pageflags are not
scarce due to SPARSEMEM using page flags for its sectionid on 32 bit NUMA
platforms.

Additional page flag definitions can be added to the CONFIG_PAGEFLAGS_EXTENDED
section in page-flags.h if the functionality depends on PAGEFLAGS_EXTENDED or
if more page flag overlapping tricks are used for the !PAGEFLAGS_EXTENDED
fallback (the upcoming virtual compound patch may hook in here and Rik's/Lee's
additional page flags to solve the reclaim issues could also be added there
[hint...  hint...  where are these patchsets?]).

Avoiding the overlaying of Pg_reclaim also clears the way for possible use of
compound pages for the pagecache or on the LRU.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:22 -07:00
Paul Mundt d5f68c6dbd sh: Bump number of quicklists for SH-5.
Sync up with the SH definitions.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-01-28 13:18:55 +09:00
Geoff Levand a5ee6daa52 sparsemem: make SPARSEMEM_VMEMMAP selectable
SPARSEMEM_VMEMMAP needs to be a selectable config option to support
building the kernel both with and without sparsemem vmemmap support.  This
selection is desirable for platforms which could be configured one way for
platform specific builds and the other for multi-platform builds.

Signed-off-by: Miguel Botón <mboton@gmail.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-17 19:28:16 -08:00
Philipp Marek ad3d0a3827 small documentation fixes
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-20 02:46:58 +02:00
Linus Torvalds fb9fc39517 Merge branch 'xen-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'xen-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xfs: eagerly remove vmap mappings to avoid upsetting Xen
  xen: add some debug output for failed multicalls
  xen: fix incorrect vcpu_register_vcpu_info hypercall argument
  xen: ask the hypervisor how much space it needs reserved
  xen: lock pte pages while pinning/unpinning
  xen: deal with stale cr3 values when unpinning pagetables
  xen: add batch completion callbacks
  xen: yield to IPI target if necessary
  Clean up duplicate includes in arch/i386/xen/
  remove dead code in pgtable_cache_init
  paravirt: clean up lazy mode handling
  paravirt: refactor struct paravirt_ops into smaller pv_*_ops
2007-10-17 11:10:11 -07:00
Jeremy Fitzhardinge 74260714c5 xen: lock pte pages while pinning/unpinning
When a pagetable is created, it is made globally visible in the rmap
prio tree before it is pinned via arch_dup_mmap(), and remains in the
rmap tree while it is unpinned with arch_exit_mmap().

This means that other CPUs may race with the pinning/unpinning
process, and see a pte between when it gets marked RO and actually
pinned, causing any pte updates to fail with write-protect faults.

As a result, all pte pages must be properly locked, and only unlocked
once the pinning/unpinning process has finished.

In order to avoid taking spinlocks for the whole pagetable - which may
overflow the PREEMPT_BITS portion of preempt counter - it locks and pins
each pte page individually, and then finally pins the whole pagetable.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickens <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Keir Fraser <keir@xensource.com>
Cc: Jan Beulich <jbeulich@novell.com>
2007-10-16 11:51:30 -07:00
KAMEZAWA Hiroyuki 0c0e619589 memory unplug: page offline
Logic.
 - set all pages in  [start,end)  as isolated migration-type.
   by this, all free pages in the range will be not-for-use.
 - Migrate all LRU pages in the range.
 - Test all pages in the range's refcnt is zero or not.

Todo:
 - allocate migration destination page from better area.
 - confirm page_count(page)== 0 && PageReserved(page) page is safe to be freed..
 (I don't like this kind of page but..
 - Find out pages which cannot be migrated.
 - more running tests.
 - Use reclaim for unplugging other memory type area.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:02 -07:00
Andy Whitcroft 29c71111d0 vmemmap: generify initialisation via helpers
Convert the common vmemmap population into initialisation helpers for use by
architecture vmemmap populators.  All architecture implementing the
SPARSEMEM_VMEMMAP variant supply an architecture specific vmemmap_populate()
initialiser, which may make use of the helpers.

This allows us to clean up and remove the initialisation Kconfig entries.
With this patch there is a single SPARSEMEM_VMEMMAP_ENABLE Kconfig option to
indicate use of that variant.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:51 -07:00
Jeremy Fitzhardinge 67dd5a25f4 xen: disable split pte locks for now
When pinning and unpinning pagetables, we must protect them against
being used by other CPUs, lest they see the pagetable in an
intermediate read-only-but-not-pinned state.

When using split pte locks, doing this properly would require taking
all the pte locks for the pagetable while pinning, but this may overflow
the PREEMPT_BITS part of the preempt counter if the process has mapped
more than about 512M of memory.

However, failing to take the pte locks causes write-protect faults when
the pageout code is trying to clear the Access bit on a pte which is part
of a freshy created and still being pinned process after fork.

This is a short-term fix until the problem is solved properly.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Keir Fraser <keir@xensource.com>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-06 09:31:30 -07:00
Rafael J. Wysocki b0cb1a19d0 Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION
Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION to avoid
confusion (among other things, with CONFIG_SUSPEND introduced in the
next patch).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-29 16:45:38 -07:00
Christoph Lameter 2a7326b5bb CONFIG_BOUNCE to avoid useless inclusion of bounce buffer logic
The bounce buffer logic is included on systems that do not need it.  If a
system does not have zones like ZONE_DMA and ZONE_HIGHMEM that can lead to
the use of bounce buffers then there is no need to reserve memory pools etc
etc.  This is true f.e.  for SGI Altix.

Also nicifies the Makefile and gets rid of the tricky "and" there.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 10:23:02 -07:00
Linus Torvalds b91cba52e9 Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6: (68 commits)
  sh: sh-rtc support for SH7709.
  sh: Revert __xdiv64_32 size change.
  sh: Update r7785rp defconfig.
  sh: Export div symbols for GCC 4.2 and ST GCC.
  sh: fix race in parallel out-of-tree build
  sh: Kill off dead mach.c for hp6xx.
  sh: hd64461.h cleanup and added comments.
  sh: Update the alignment when 4K stacks are used.
  sh: Add a .bss.page_aligned section for 4K stacks.
  sh: Don't let SH-4A clobber SH-4 CFLAGS.
  sh: Add parport stub for SuperIO ports.
  sh: Drop -Wa,-dsp for DSP tuning.
  sh: Update dreamcast defconfig.
  fb: pvr2fb: A few more __devinit annotations for PCI.
  fb: pvr2fb: Fix up section mismatch warnings.
  sh: Select IPR-IRQ for SH7091.
  sh: Correct __xdiv64_32/div64_32 return value size.
  sh: Fix timer-tmu build for SH-3.
  sh: Add cpu and mach links to CLEAN_FILES.
  sh: Preliminary support for the SH-X3 CPU.
  ...
2007-07-16 10:32:02 -07:00
Stephen Rothwell f057eac0d7 Introduce CONFIG_VIRT_TO_BUS
Make some offending drivers depend on it and set CONFIG_ARCH_NO_VIRT_TO_BUS
for ppc64 so that we don't build those drivers.

This gets PowerPC allmodconfig and allyesconfig much closer to building.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@ftp.linux.org.uk>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:42 -07:00
Paul Mundt 33d63bd83b sh: memory hot-add for sparsemem users support.
This enables simple hotplug support for sparsemem users. Presently
this only permits memory being added in to node 0 on ZONE_NORMAL.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-06-08 02:43:51 +00:00
Paul Mundt 6c645ac725 sh64: generic quicklist support.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-14 09:55:35 +09:00
Paul Mundt 5f8c9908f2 sh: generic quicklist support.
This moves SH over to the generic quicklists. As per x86_64,
we have special mappings for the PGDs, so these go on their
own list..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-09 01:35:00 +00:00
Christoph Lameter 6225e93735 Quicklists for page table pages
On x86_64 this cuts allocation overhead for page table pages down to a
fraction (kernel compile / editing load.  TSC based measurement of times spend
in each function):

no quicklist

pte_alloc               1569048 4.3s(401ns/2.7us/179.7us)
pmd_alloc                780988 2.1s(337ns/2.7us/86.1us)
pud_alloc                780072 2.2s(424ns/2.8us/300.6us)
pgd_alloc                260022 1s(920ns/4us/263.1us)

quicklist:

pte_alloc                452436 573.4ms(8ns/1.3us/121.1us)
pmd_alloc                196204 174.5ms(7ns/889ns/46.1us)
pud_alloc                195688 172.4ms(7ns/881ns/151.3us)
pgd_alloc                 65228 9.8ms(8ns/150ns/6.1us)

pgd allocations are the most complex and there we see the most dramatic
improvement (may be we can cut down the amount of pgds cached somewhat?).  But
even the pte allocations still see a doubling of performance.

1. Proven code from the IA64 arch.

	The method used here has been fine tuned for years and
	is NUMA aware. It is based on the knowledge that accesses
	to page table pages are sparse in nature. Taking a page
	off the freelists instead of allocating a zeroed pages
	allows a reduction of number of cachelines touched
	in addition to getting rid of the slab overhead. So
	performance improves. This is particularly useful if pgds
	contain standard mappings. We can save on the teardown
	and setup of such a page if we have some on the quicklists.
	This includes avoiding lists operations that are otherwise
	necessary on alloc and free to track pgds.

2. Light weight alternative to use slab to manage page size pages

	Slab overhead is significant and even page allocator use
	is pretty heavy weight. The use of a per cpu quicklist
	means that we touch only two cachelines for an allocation.
	There is no need to access the page_struct (unless arch code
	needs to fiddle around with it). So the fast past just
	means bringing in one cacheline at the beginning of the
	page. That same cacheline may then be used to store the
	page table entry. Or a second cacheline may be used
	if the page table entry is not in the first cacheline of
	the page. The current code will zero the page which means
	touching 32 cachelines (assuming 128 byte). We get down
	from 32 to 2 cachelines in the fast path.

3. x86_64 gets lightweight page table page management.

	This will allow x86_64 arch code to faster repopulate pgds
	and other page table entries. The list operations for pgds
	are reduced in the same way as for i386 to the point where
	a pgd is allocated from the page allocator and when it is
	freed back to the page allocator. A pgd can pass through
	the quicklists without having to be reinitialized.

64 Consolidation of code from multiple arches

	So far arches have their own implementation of quicklist
	management. This patch moves that feature into the core allowing
	an easier maintenance and consistent management of quicklists.

Page table pages have the characteristics that they are typically zero or in a
known state when they are freed.  This is usually the exactly same state as
needed after allocation.  So it makes sense to build a list of freed page
table pages and then consume the pages already in use first.  Those pages have
already been initialized correctly (thus no need to zero them) and are likely
already cached in such a way that the MMU can use them most effectively.  Page
table pages are used in a sparse way so zeroing them on allocation is not too
useful.

Such an implementation already exits for ia64.  Howver, that implementation
did not support constructors and destructors as needed by i386 / x86_64.  It
also only supported a single quicklist.  The implementation here has
constructor and destructor support as well as the ability for an arch to
specify how many quicklists are needed.

Quicklists are defined by an arch defining CONFIG_QUICKLIST.  If more than one
quicklist is necessary then we can define NR_QUICK for additional lists.  F.e.
 i386 needs two and thus has

config NR_QUICK
	int
	default 2

If an arch has requested quicklist support then pages can be allocated
from the quicklist (or from the page allocator if the quicklist is
empty) via:

quicklist_alloc(<quicklist-nr>, <gfpflags>, <constructor>)

Page table pages can be freed using:

quicklist_free(<quicklist-nr>, <destructor>, <page>)

Pages must have a definite state after allocation and before
they are freed. If no constructor is specified then pages
will be zeroed on allocation and must be zeroed before they are
freed.

If a constructor is used then the constructor will establish
a definite page state. F.e. the i386 and x86_64 pgd constructors
establish certain mappings.

Constructors and destructors can also be used to track the pages.
i386 and x86_64 use a list of pgds in order to be able to dynamically
update standard mappings.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:54 -07:00
Christoph Lameter 5ac6da669e [PATCH] Set CONFIG_ZONE_DMA for arches with GENERIC_ISA_DMA
As Andi pointed out: CONFIG_GENERIC_ISA_DMA only disables the ISA DMA
channel management.  Other functionality may still expect GFP_DMA to
provide memory below 16M.  So we need to make sure that CONFIG_ZONE_DMA is
set independent of CONFIG_GENERIC_ISA_DMA.  Undo the modifications to
mm/Kconfig where we made ZONE_DMA dependent on GENERIC_ISA_DMA and set
theses explicitly in each arches Kconfig.

Reviews must occur for each arch in order to determine if ZONE_DMA can be
switched off.  It can only be switched off if we know that all devices
supported by a platform are capable of performing DMA transfers to all of
memory (Some arches already support this: uml, avr32, sh sh64, parisc and
IA64/Altix).

In order to switch ZONE_DMA off conditionally, one would have to establish
a scheme by which one can assure that no drivers are enabled that are only
capable of doing I/O to a part of memory, or one needs to provide an
alternate means of performing an allocation from a specific range of memory
(like provided by alloc_pages_range()) and insure that all drivers use that
call.  In that case the arches alloc_dma_coherent() may need to be modified
to call alloc_pages_range() instead of relying on GFP_DMA.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:19 -08:00
Christoph Lameter 4b51d66989 [PATCH] optional ZONE_DMA: optional ZONE_DMA in the VM
Make ZONE_DMA optional in core code.

- ifdef all code for ZONE_DMA and related definitions following the example
  for ZONE_DMA32 and ZONE_HIGHMEM.

- Without ZONE_DMA, ZONE_HIGHMEM and ZONE_DMA32 we get to a ZONES_SHIFT of
  0.

- Modify the VM statistics to work correctly without a DMA zone.

- Modify slab to not create DMA slabs if there is no ZONE_DMA.

[akpm@osdl.org: cleanup]
[jdike@addtoit.com: build fix]
[apw@shadowen.org: Simplify calculation of the number of bits we need for ZONES_SHIFT]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:18 -08:00
Christoph Lameter 66701b1499 [PATCH] optional ZONE_DMA: introduce CONFIG_ZONE_DMA
This patch simply defines CONFIG_ZONE_DMA for all arches.  We later do special
things with CONFIG_ZONE_DMA after the VM and an arch are prepared to work
without ZONE_DMA.

CONFIG_ZONE_DMA can be defined in two ways depending on how an architecture
handles ISA DMA.

First if CONFIG_GENERIC_ISA_DMA is set by the arch then we know that the arch
needs ZONE_DMA because ISA DMA devices are supported.  We can catch this in
mm/Kconfig and do not need to modify arch code.

Second, arches may use ZONE_DMA in an unknown way.  We set CONFIG_ZONE_DMA for
all arches that do not set CONFIG_GENERIC_ISA_DMA in order to insure backwards
compatibility.  The arches may later undefine ZONE_DMA if their arch code has
been verified to not depend on ZONE_DMA.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:18 -08:00
Matt LaPlante 84eb8d0608 Fix "can not" in Documentation and Kconfig
Randy brought it to my attention that in proper english "can not" should always
be written "cannot". I donot see any reason to argue, even if I mightnot
understand why this rule exists.  This patch fixes "can not" in several
Documentation files as well as three Kconfigs.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03 22:53:09 +02:00
Matt LaPlante 44c09201a4 more misc typo fixes
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03 22:34:14 +02:00
Keith Mannthey ec69acbb11 [PATCH] hot-add-mem x86_64: Kconfig changes
Create Kconfig namespace for MEMORY_HOTPLUG_RESERVE and MEMORY_HOTPLUG_SPARSE.
 This is needed to create a disticiton between the 2 paths.  Selecting the
high level opiton of MEMORY_HOTPLUG will get you MEMORY_HOTPLUG_SPARSE if you
have sparsemem enabled or MEMORY_HOTPLUG_RESERVE if you are x86_64 with
discontig and ACPI numa support.

Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:18 -07:00
Linus Torvalds 1903ac54f8 Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6:
  [PATCH] i386: export memory more than 4G through /proc/iomem
  [PATCH] 64bit Resource: finally enable 64bit resource sizes
  [PATCH] 64bit Resource: convert a few remaining drivers to use resource_size_t where needed
  [PATCH] 64bit resource: change pnp core to use resource_size_t
  [PATCH] 64bit resource: change pci core and arch code to use resource_size_t
  [PATCH] 64bit resource: change resource core to use resource_size_t
  [PATCH] 64bit resource: introduce resource_size_t for the start and end of struct resource
  [PATCH] 64bit resource: fix up printks for resources in misc drivers
  [PATCH] 64bit resource: fix up printks for resources in arch and core code
  [PATCH] 64bit resource: fix up printks for resources in pcmcia drivers
  [PATCH] 64bit resource: fix up printks for resources in video drivers
  [PATCH] 64bit resource: fix up printks for resources in ide drivers
  [PATCH] 64bit resource: fix up printks for resources in mtd drivers
  [PATCH] 64bit resource: fix up printks for resources in pci core and hotplug drivers
  [PATCH] 64bit resource: fix up printks for resources in networks drivers
  [PATCH] 64bit resource: fix up printks for resources in sound drivers
  [PATCH] 64bit resource: C99 changes for struct resource declarations

Fixed up trivial conflict in drivers/ide/pci/cmd64x.c (the printk that
was changed by the 64-bit resources had been deleted in the meantime ;)
2006-06-29 10:49:17 -07:00
Yasunori Goto cc57637b0b [PATCH] solve config broken: undefined reference to `online_page'
Memory hotplug code of i386 adds memory to only highmem.  So, if
CONFIG_HIGHMEM is not set, CONFIG_MEMORY_HOTPLUG shouldn't be set.
Otherwise, it causes compile error.

In addition, many architecture can't use memory hotplug feature yet.  So, I
introduce CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-29 10:26:20 -07:00
Yasunori Goto 1f04bbd2d3 [PATCH] sparc64: support sparsemem and !memory hotplug
Fix "undefined reference to `arch_add_memory'" on sparc64 allmodconfig.

sparc64 doesn't support memory hotplug.  But we want it to support
sparsemem.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:36 -07:00
Greg Kroah-Hartman 6550e07f41 [PATCH] 64bit Resource: finally enable 64bit resource sizes
Introduce the Kconfig entry and actually switch to a 64bit value, if
wanted, for resource_size_t.

Based on a patch series originally from Vivek Goyal <vgoyal@in.ibm.com>

Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-27 09:24:00 -07:00
Christoph Lameter 6c5240ae7f [PATCH] Swapless page migration: modify core logic
Use the migration entries for page migration

This modifies the migration code to use the new migration entries.  It now
becomes possible to migrate anonymous pages without having to add a swap
entry.

We add a couple of new functions to replace migration entries with the proper
ptes.

We cannot take the tree_lock for migrating anonymous pages anymore.  However,
we know that we hold the only remaining reference to the page when the page
count reaches 1.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 07:42:50 -07:00
Christoph Lameter d784124cfe [PATCH] mm: make page migration dependent on swap and NUMA
The page migration code could function without NUMA but we currently have
no users for the non-NUMA case.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:50 -08:00