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Commit Graph

159 Commits

Author SHA1 Message Date
Sasha Levin
28b24c1fc8 mm: cma: debugfs interface
I've noticed that there is no interfaces exposed by CMA which would let me
fuzz what's going on in there.

This small patchset exposes some information out to userspace, plus adds
the ability to trigger allocation and freeing from userspace.

This patch (of 3):

Implement a simple debugfs interface to expose information about CMA areas
in the system.

Useful for testing/sanity checks for CMA since it was impossible to
previously retrieve this information in userspace.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 16:49:00 -07:00
Linus Torvalds
b11a278397 Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kconfig updates from Michal Marek:
 "Yann E Morin was supposed to take over kconfig maintainership, but
  this hasn't happened.  So I'm sending a few kconfig patches that I
  collected:

   - Fix for missing va_end in kconfig
   - merge_config.sh displays used if given too few arguments
   - s/boolean/bool/ in Kconfig files for consistency, with the plan to
     only support bool in the future"

* 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kconfig: use va_end to match corresponding va_start
  merge_config.sh: Display usage if given too few arguments
  kconfig: use bool instead of boolean for type definition attributes
2015-02-19 10:36:45 -08:00
Ganesh Mahendran
0f050d997e mm/zsmalloc: add statistics support
Keeping fragmentation of zsmalloc in a low level is our target.  But now
we still need to add the debug code in zsmalloc to get the quantitative
data.

This patch adds a new configuration CONFIG_ZSMALLOC_STAT to enable the
statistics collection for developers.  Currently only the objects
statatitics in each class are collected.  User can get the information via
debugfs.

     cat /sys/kernel/debug/zsmalloc/zram0/...

For example:

After I copied "jdk-8u25-linux-x64.tar.gz" to zram with ext4 filesystem:
 class  size obj_allocated   obj_used pages_used
     0    32             0          0          0
     1    48           256         12          3
     2    64            64         14          1
     3    80            51          7          1
     4    96           128          5          3
     5   112            73          5          2
     6   128            32          4          1
     7   144             0          0          0
     8   160             0          0          0
     9   176             0          0          0
    10   192             0          0          0
    11   208             0          0          0
    12   224             0          0          0
    13   240             0          0          0
    14   256            16          1          1
    15   272            15          9          1
    16   288             0          0          0
    17   304             0          0          0
    18   320             0          0          0
    19   336             0          0          0
    20   352             0          0          0
    21   368             0          0          0
    22   384             0          0          0
    23   400             0          0          0
    24   416             0          0          0
    25   432             0          0          0
    26   448             0          0          0
    27   464             0          0          0
    28   480             0          0          0
    29   496            33          1          4
    30   512             0          0          0
    31   528             0          0          0
    32   544             0          0          0
    33   560             0          0          0
    34   576             0          0          0
    35   592             0          0          0
    36   608             0          0          0
    37   624             0          0          0
    38   640             0          0          0
    40   672             0          0          0
    42   704             0          0          0
    43   720            17          1          3
    44   736             0          0          0
    46   768             0          0          0
    49   816             0          0          0
    51   848             0          0          0
    52   864            14          1          3
    54   896             0          0          0
    57   944            13          1          3
    58   960             0          0          0
    62  1024             4          1          1
    66  1088            15          2          4
    67  1104             0          0          0
    71  1168             0          0          0
    74  1216             0          0          0
    76  1248             0          0          0
    83  1360             3          1          1
    91  1488            11          1          4
    94  1536             0          0          0
   100  1632             5          1          2
   107  1744             0          0          0
   111  1808             9          1          4
   126  2048             4          4          2
   144  2336             7          3          4
   151  2448             0          0          0
   168  2720            15         15         10
   190  3072            28         27         21
   202  3264             0          0          0
   254  4096         36209      36209      36209

 Total               37022      36326      36288

We can calculate the overall fragentation by the last line:
    Total               37022      36326      36288
    (37022 - 36326) / 37022 = 1.87%

Also by analysing objects alocated in every class we know why we got so
low fragmentation: Most of the allocated objects is in <class 254>.  And
there is only 1 page in class 254 zspage.  So, No fragmentation will be
introduced by allocating objs in class 254.

And in future, we can collect other zsmalloc statistics as we need and
analyse them.

Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Christoph Jaeger
6341e62b21 kconfig: use bool instead of boolean for type definition attributes
Support for keyword 'boolean' will be dropped later on.

No functional change.

Reference: http://lkml.kernel.org/r/cover.1418003065.git.cj@linux.com
Signed-off-by: Christoph Jaeger <cj@linux.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-01-07 13:08:04 +01:00
Pranith Kumar
83fe27ea53 rcu: Make SRCU optional by using CONFIG_SRCU
SRCU is not necessary to be compiled by default in all cases. For tinification
efforts not compiling SRCU unless necessary is desirable.

The current patch tries to make compiling SRCU optional by introducing a new
Kconfig option CONFIG_SRCU which is selected when any of the components making
use of SRCU are selected.

If we do not select CONFIG_SRCU, srcu.o will not be compiled at all.

   text    data     bss     dec     hex filename
   2007       0       0    2007     7d7 kernel/rcu/srcu.o

Size of arch/powerpc/boot/zImage changes from

   text    data     bss     dec     hex filename
 831552   64180   23944  919676   e087c arch/powerpc/boot/zImage : before
 829504   64180   23952  917636   e0084 arch/powerpc/boot/zImage : after

so the savings are about ~2000 bytes.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ]
2015-01-06 11:04:29 -08:00
Konstantin Khlebnikov
09316c09dd mm/balloon_compaction: add vmstat counters and kpageflags bit
Always mark pages with PageBalloon even if balloon compaction is disabled
and expose this mark in /proc/kpageflags as KPF_BALLOON.

Also this patch adds three counters into /proc/vmstat: "balloon_inflate",
"balloon_deflate" and "balloon_migrate".  They accumulate balloon
activity.  Current size of balloon is (balloon_inflate - balloon_deflate)
pages.

All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON.
It should be selected by ballooning driver which wants use this feature.
Currently virtio-balloon is the only user.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:26:01 -04:00
Steve Capper
2667f50e8b mm: introduce a general RCU get_user_pages_fast()
This series implements general forms of get_user_pages_fast and
__get_user_pages_fast in core code and activates them for arm and arm64.

These are required for Transparent HugePages to function correctly, as a
futex on a THP tail will otherwise result in an infinite loop (due to the
core implementation of __get_user_pages_fast always returning 0).

Unfortunately, a futex on THP tail can be quite common for certain
workloads; thus THP is unreliable without a __get_user_pages_fast
implementation.

This series may also be beneficial for direct-IO heavy workloads and
certain KVM workloads.

This patch (of 6):

get_user_pages_fast() attempts to pin user pages by walking the page
tables directly and avoids taking locks.  Thus the walker needs to be
protected from page table pages being freed from under it, and needs to
block any THP splits.

One way to achieve this is to have the walker disable interrupts, and rely
on IPIs from the TLB flushing code blocking before the page table pages
are freed.

On some platforms we have hardware broadcast of TLB invalidations, thus
the TLB flushing code doesn't necessarily need to broadcast IPIs; and
spuriously broadcasting IPIs can hurt system performance if done too
often.

This problem has been solved on PowerPC and Sparc by batching up page
table pages belonging to more than one mm_user, then scheduling an
rcu_sched callback to free the pages.  This RCU page table free logic has
been promoted to core code and is activated when one enables
HAVE_RCU_TABLE_FREE.  Unfortunately, these architectures implement their
own get_user_pages_fast routines.

The RCU page table free logic coupled with an IPI broadcast on THP split
(which is a rare event), allows one to protect a page table walker by
merely disabling the interrupts during the walk.

This patch provides a general RCU implementation of get_user_pages_fast
that can be used by architectures that perform hardware broadcast of TLB
invalidations.

It is based heavily on the PowerPC implementation by Nick Piggin.

[akpm@linux-foundation.org: various comment fixes]
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:26:00 -04:00
Dan Streetman
12d79d64bf mm/zpool: update zswap to use zpool
Change zswap to use the zpool api instead of directly using zbud.  Add a
boot-time param to allow selecting which zpool implementation to use,
with zbud as the default.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Tested-by: Seth Jennings <sjennings@variantweb.net>
Cc: Weijie Yang <weijie.yang@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:23 -07:00
Dan Streetman
af8d417a04 mm/zpool: implement common zpool api to zbud/zsmalloc
Add zpool api.

zpool provides an interface for memory storage, typically of compressed
memory.  Users can select what backend to use; currently the only
implementations are zbud, a low density implementation with up to two
compressed pages per storage page, and zsmalloc, a higher density
implementation with multiple compressed pages per storage page.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Tested-by: Seth Jennings <sjennings@variantweb.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Weijie Yang <weijie.yang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:23 -07:00
Joonsoo Kim
a254129e86 CMA: generalize CMA reserved area management functionality
Currently, there are two users on CMA functionality, one is the DMA
subsystem and the other is the KVM on powerpc.  They have their own code
to manage CMA reserved area even if they looks really similar.  From my
guess, it is caused by some needs on bitmap management.  KVM side wants
to maintain bitmap not for 1 page, but for more size.  Eventually it use
bitmap where one bit represents 64 pages.

When I implement CMA related patches, I should change those two places
to apply my change and it seem to be painful to me.  I want to change
this situation and reduce future code management overhead through this
patch.

This change could also help developer who want to use CMA in their new
feature development, since they can use CMA easily without copying &
pasting this reserved area management code.

In previous patches, we have prepared some features to generalize CMA
reserved area management and now it's time to do it.  This patch moves
core functions to mm/cma.c and change DMA APIs to use these functions.

There is no functional change in DMA APIs.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Gleb Natapov <gleb@kernel.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:16 -07:00
Minchan Kim
d867f203b9 mm/zsmalloc: make zsmalloc module-buildable
Now, we can build zsmalloc as module because unmap_kernel_range was
exported.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:14 -07:00
Konstantin Khlebnikov
226b4ccdcb mm/process_vm_access: move config option into init/Kconfig
CONFIG_CROSS_MEMORY_ATTACH adds couple syscalls: process_vm_readv and
process_vm_writev, it's a kind of IPC for copying data between processes.
Currently this option is placed inside "Processor type and features".

This patch moves it into "General setup" (where all other arch-independed
syscalls and ipc features are placed) and changes prompt string to less
cryptic.

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Christopher Yeoh <cyeoh@au1.ibm.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:12 -07:00
Naoya Horiguchi
c177c81e09 hugetlb: restrict hugepage_migration_support() to x86_64
Currently hugepage migration is available for all archs which support
pmd-level hugepage, but testing is done only for x86_64 and there're
bugs for other archs.  So to avoid breaking such archs, this patch
limits the availability strictly to x86_64 until developers of other
archs get interested in enabling this feature.

Simply disabling hugepage migration on non-x86_64 archs is not enough to
fix the reported problem where sys_move_pages() hits the BUG_ON() in
follow_page(FOLL_GET), so let's fix this by checking if hugepage
migration is supported in vma_migratable().

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>	[3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:51 -07:00
Philipp Hachtmann
70210ed950 mm/memblock: add physical memory list
Add the physmem list to the memblock structure. This list only exists
if HAVE_MEMBLOCK_PHYS_MAP is selected and contains the unmodified
list of physically available memory. It differs from the memblock
memory list as it always contains all memory ranges even if the
memory has been restricted, e.g. by use of the mem= kernel parameter.

Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20 08:58:39 +02:00
Helge Deller
042d27acb6 parisc,metag: Do not hardcode maximum userspace stack size
This patch affects only architectures where the stack grows upwards
(currently parisc and metag only). On those do not hardcode the maximum
initial stack size to 1GB for 32-bit processes, but make it configurable
via a config option.

The main problem with the hardcoded stack size is, that we have two
memory regions which grow upwards: stack and heap. To keep most of the
memory available for heap in a flexmap memory layout, it makes no sense
to hard allocate up to 1GB of the memory for stack which can't be used
as heap then.

This patch makes the stack size for 32-bit processes configurable and
uses 80MB as default value which has been in use during the last few
years on parisc and which hasn't showed any problems yet.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>
2014-05-15 00:01:41 +01:00
Mark Salter
9e5c33d7ae mm: create generic early_ioremap() support
This patch creates a generic implementation of early_ioremap() support
based on the existing x86 implementation.  early_ioremp() is useful for
early boot code which needs to temporarily map I/O or memory regions
before normal mapping functions such as ioremap() are available.

Some architectures have optional MMU.  In the no-MMU case, the remap
functions simply return the passed in physical address and the unmap
functions do nothing.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:15 -07:00
Kirill A. Shutemov
9164550ecd mm: disable split page table lock for !MMU
There's no reason to enable split page table lock if don't have page
tables.

It also triggers build error at least on ARM since we don't define
pmd_page() for !MMU.

  In file included from arch/arm/kernel/asm-offsets.c:14:0:
  include/linux/mm.h: In function 'pte_lockptr':
  include/linux/mm.h:1392:2: error: implicit declaration of function 'pmd_page' [-Werror=implicit-function-declaration]
  include/linux/mm.h:1392:2: warning: passing argument 1 of 'ptlock_ptr' makes pointer from integer without a cast [enabled by default]
  include/linux/mm.h:1384:27: note: expected 'struct page *' but argument is of type 'int'

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:35:52 -07:00
Ben Hutchings
2216ee8530 mm/Kconfig: fix URL for zsmalloc benchmark
The help text for CONFIG_PGTABLE_MAPPING has an incorrect URL.  While
we're at it, remove the unnecessary footnote notation.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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>
2014-03-10 17:26:20 -07:00
Minchan Kim
bcf1647d08 zsmalloc: move it under mm
This patch moves zsmalloc under mm directory.

Before that, description will explain why we have needed custom
allocator.

Zsmalloc is a new slab-based memory allocator for storing compressed
pages.  It is designed for low fragmentation and high allocation success
rate on large object, but <= PAGE_SIZE allocations.

zsmalloc differs from the kernel slab allocator in two primary ways to
achieve these design goals.

zsmalloc never requires high order page allocations to back slabs, or
"size classes" in zsmalloc terms.  Instead it allows multiple
single-order pages to be stitched together into a "zspage" which backs
the slab.  This allows for higher allocation success rate under memory
pressure.

Also, zsmalloc allows objects to span page boundaries within the zspage.
This allows for lower fragmentation than could be had with the kernel
slab allocator for objects between PAGE_SIZE/2 and PAGE_SIZE.  With the
kernel slab allocator, if a page compresses to 60% of it original size,
the memory savings gained through compression is lost in fragmentation
because another object of the same size can't be stored in the leftover
space.

This ability to span pages results in zsmalloc allocations not being
directly addressable by the user.  The user is given an
non-dereferencable handle in response to an allocation request.  That
handle must be mapped, using zs_map_object(), which returns a pointer to
the mapped region that can be used.  The mapping is necessary since the
object data may reside in two different noncontigious pages.

The zsmalloc fulfills the allocation needs for zram perfectly

[sjenning@linux.vnet.ibm.com: borrow Seth's quote]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30 16:56:55 -08:00
Sima Baymani
a844f38671 mm: add missing dependency in Kconfig
Eliminate the following (rand)config warning by adding missing PROC_FS
dependency:

  warning: (HWPOISON_INJECT && MEM_SOFT_DIRTY) selects PROC_PAGE_MONITOR which has unmet direct dependencies (PROC_FS && MMU)

Signed-off-by: Sima Baymani <sima.baymani@gmail.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-18 19:04:52 -08:00
Linus Torvalds
9073e1a804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "Usual earth-shaking, news-breaking, rocket science pile from
  trivial.git"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
  doc: usb: Fix typo in Documentation/usb/gadget_configs.txt
  doc: add missing files to timers/00-INDEX
  timekeeping: Fix some trivial typos in comments
  mm: Fix some trivial typos in comments
  irq: Fix some trivial typos in comments
  NUMA: fix typos in Kconfig help text
  mm: update 00-INDEX
  doc: Documentation/DMA-attributes.txt fix typo
  DRM: comment: `halve' -> `half'
  Docs: Kconfig: `devlopers' -> `developers'
  doc: typo on word accounting in kprobes.c in mutliple architectures
  treewide: fix "usefull" typo
  treewide: fix "distingush" typo
  mm/Kconfig: Grammar s/an/a/
  kexec: Typo s/the/then/
  Documentation/kvm: Update cpuid documentation for steal time and pv eoi
  treewide: Fix common typo in "identify"
  __page_to_pfn: Fix typo in comment
  Correct some typos for word frequency
  clk: fixed-factor: Fix a trivial typo
  ...
2013-11-15 16:47:22 -08:00
Kirill A. Shutemov
49076ec2cc mm: dynamically allocate page->ptl if it cannot be embedded to struct page
If split page table lock is in use, we embed the lock into struct page
of table's page.  We have to disable split lock, if spinlock_t is too
big be to be embedded, like when DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC
enabled.

This patch add support for dynamic allocation of split page table lock
if we can't embed it to struct page.

page->ptl is unsigned long now and we use it as spinlock_t if
sizeof(spinlock_t) <= sizeof(long), otherwise it's pointer to spinlock_t.

The spinlock_t allocated in pgtable_page_ctor() for PTE table and in
pgtable_pmd_page_ctor() for PMD table.  All other helpers converted to
support dynamically allocated page->ptl.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:20 +09:00
Kirill A. Shutemov
e009bb30c8 mm: implement split page table lock for PMD level
The basic idea is the same as with PTE level: the lock is embedded into
struct page of table's page.

We can't use mm->pmd_huge_pte to store pgtables for THP, since we don't
take mm->page_table_lock anymore.  Let's reuse page->lru of table's page
for that.

pgtable_pmd_page_ctor() returns true, if initialization is successful
and false otherwise.  Current implementation never fails, but assumption
that constructor can fail will help to port it to -rt where spinlock_t
is rather huge and cannot be embedded into struct page -- dynamic
allocation is required.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:15 +09:00
Kirill A. Shutemov
e9bb18c7b9 mm: avoid increase sizeof(struct page) due to split page table lock
Alex Thorlton noticed that some massively threaded workloads work poorly,
if THP enabled.  This patchset fixes this by introducing split page table
lock for PMD tables.  hugetlbfs is not covered yet.

This patchset is based on work by Naoya Horiguchi.

: akpm result summary:
:
: THP off, v3.12-rc2: 18.059261877 seconds time elapsed
: THP off, patched:   16.768027318 seconds time elapsed
:
: THP on, v3.12-rc2:  42.162306788 seconds time elapsed
: THP on, patched:    8.397885779 seconds time elapsed
:
: HUGETLB, v3.12-rc2: 47.574936948 seconds time elapsed
: HUGETLB, patched:   19.447481153 seconds time elapsed

THP off, v3.12-rc2:
-------------------

 Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs):

    1037072.835207 task-clock                #   57.426 CPUs utilized            ( +-  3.59% )
            95,093 context-switches          #    0.092 K/sec                    ( +-  3.93% )
               140 cpu-migrations            #    0.000 K/sec                    ( +-  5.28% )
        10,000,550 page-faults               #    0.010 M/sec                    ( +-  0.00% )
 2,455,210,400,261 cycles                    #    2.367 GHz                      ( +-  3.62% ) [83.33%]
 2,429,281,882,056 stalled-cycles-frontend   #   98.94% frontend cycles idle     ( +-  3.67% ) [83.33%]
 1,975,960,019,659 stalled-cycles-backend    #   80.48% backend  cycles idle     ( +-  3.88% ) [66.68%]
    46,503,296,013 instructions              #    0.02  insns per cycle
                                             #   52.24  stalled cycles per insn  ( +-  3.21% ) [83.34%]
     9,278,997,542 branches                  #    8.947 M/sec                    ( +-  4.00% ) [83.34%]
        89,881,640 branch-misses             #    0.97% of all branches          ( +-  1.17% ) [83.33%]

      18.059261877 seconds time elapsed                                          ( +-  2.65% )

THP on, v3.12-rc2:
------------------

 Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs):

    3114745.395974 task-clock                #   73.875 CPUs utilized            ( +-  1.84% )
           267,356 context-switches          #    0.086 K/sec                    ( +-  1.84% )
                99 cpu-migrations            #    0.000 K/sec                    ( +-  1.40% )
            58,313 page-faults               #    0.019 K/sec                    ( +-  0.28% )
 7,416,635,817,510 cycles                    #    2.381 GHz                      ( +-  1.83% ) [83.33%]
 7,342,619,196,993 stalled-cycles-frontend   #   99.00% frontend cycles idle     ( +-  1.88% ) [83.33%]
 6,267,671,641,967 stalled-cycles-backend    #   84.51% backend  cycles idle     ( +-  2.03% ) [66.67%]
   117,819,935,165 instructions              #    0.02  insns per cycle
                                             #   62.32  stalled cycles per insn  ( +-  4.39% ) [83.34%]
    28,899,314,777 branches                  #    9.278 M/sec                    ( +-  4.48% ) [83.34%]
        71,787,032 branch-misses             #    0.25% of all branches          ( +-  1.03% ) [83.33%]

      42.162306788 seconds time elapsed                                          ( +-  1.73% )

HUGETLB, v3.12-rc2:
-------------------

 Performance counter stats for './thp_memscale_hugetlbfs -c 80 -b 512M' (5 runs):

    2588052.787264 task-clock                #   54.400 CPUs utilized            ( +-  3.69% )
           246,831 context-switches          #    0.095 K/sec                    ( +-  4.15% )
               138 cpu-migrations            #    0.000 K/sec                    ( +-  5.30% )
            21,027 page-faults               #    0.008 K/sec                    ( +-  0.01% )
 6,166,666,307,263 cycles                    #    2.383 GHz                      ( +-  3.68% ) [83.33%]
 6,086,008,929,407 stalled-cycles-frontend   #   98.69% frontend cycles idle     ( +-  3.77% ) [83.33%]
 5,087,874,435,481 stalled-cycles-backend    #   82.51% backend  cycles idle     ( +-  4.41% ) [66.67%]
   133,782,831,249 instructions              #    0.02  insns per cycle
                                             #   45.49  stalled cycles per insn  ( +-  4.30% ) [83.34%]
    34,026,870,541 branches                  #   13.148 M/sec                    ( +-  4.24% ) [83.34%]
        68,670,942 branch-misses             #    0.20% of all branches          ( +-  3.26% ) [83.33%]

      47.574936948 seconds time elapsed                                          ( +-  2.09% )

THP off, patched:
-----------------

 Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs):

     943301.957892 task-clock                #   56.256 CPUs utilized            ( +-  3.01% )
            86,218 context-switches          #    0.091 K/sec                    ( +-  3.17% )
               121 cpu-migrations            #    0.000 K/sec                    ( +-  6.64% )
        10,000,551 page-faults               #    0.011 M/sec                    ( +-  0.00% )
 2,230,462,457,654 cycles                    #    2.365 GHz                      ( +-  3.04% ) [83.32%]
 2,204,616,385,805 stalled-cycles-frontend   #   98.84% frontend cycles idle     ( +-  3.09% ) [83.32%]
 1,778,640,046,926 stalled-cycles-backend    #   79.74% backend  cycles idle     ( +-  3.47% ) [66.69%]
    45,995,472,617 instructions              #    0.02  insns per cycle
                                             #   47.93  stalled cycles per insn  ( +-  2.51% ) [83.34%]
     9,179,700,174 branches                  #    9.731 M/sec                    ( +-  3.04% ) [83.35%]
        89,166,529 branch-misses             #    0.97% of all branches          ( +-  1.45% ) [83.33%]

      16.768027318 seconds time elapsed                                          ( +-  2.47% )

THP on, patched:
----------------

 Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs):

     458793.837905 task-clock                #   54.632 CPUs utilized            ( +-  0.79% )
            41,831 context-switches          #    0.091 K/sec                    ( +-  0.97% )
                98 cpu-migrations            #    0.000 K/sec                    ( +-  1.66% )
            57,829 page-faults               #    0.126 K/sec                    ( +-  0.62% )
 1,077,543,336,716 cycles                    #    2.349 GHz                      ( +-  0.81% ) [83.33%]
 1,067,403,802,964 stalled-cycles-frontend   #   99.06% frontend cycles idle     ( +-  0.87% ) [83.33%]
   864,764,616,143 stalled-cycles-backend    #   80.25% backend  cycles idle     ( +-  0.73% ) [66.68%]
    16,129,177,440 instructions              #    0.01  insns per cycle
                                             #   66.18  stalled cycles per insn  ( +-  7.94% ) [83.35%]
     3,618,938,569 branches                  #    7.888 M/sec                    ( +-  8.46% ) [83.36%]
        33,242,032 branch-misses             #    0.92% of all branches          ( +-  2.02% ) [83.32%]

       8.397885779 seconds time elapsed                                          ( +-  0.18% )

HUGETLB, patched:
-----------------

 Performance counter stats for './thp_memscale_hugetlbfs -c 80 -b 512M' (5 runs):

     395353.076837 task-clock                #   20.329 CPUs utilized            ( +-  8.16% )
            55,730 context-switches          #    0.141 K/sec                    ( +-  5.31% )
               138 cpu-migrations            #    0.000 K/sec                    ( +-  4.24% )
            21,027 page-faults               #    0.053 K/sec                    ( +-  0.00% )
   930,219,717,244 cycles                    #    2.353 GHz                      ( +-  8.21% ) [83.32%]
   914,295,694,103 stalled-cycles-frontend   #   98.29% frontend cycles idle     ( +-  8.35% ) [83.33%]
   704,137,950,187 stalled-cycles-backend    #   75.70% backend  cycles idle     ( +-  9.16% ) [66.69%]
    30,541,538,385 instructions              #    0.03  insns per cycle
                                             #   29.94  stalled cycles per insn  ( +-  3.98% ) [83.35%]
     8,415,376,631 branches                  #   21.286 M/sec                    ( +-  3.61% ) [83.36%]
        32,645,478 branch-misses             #    0.39% of all branches          ( +-  3.41% ) [83.32%]

      19.447481153 seconds time elapsed                                          ( +-  2.00% )

This patch (of 11):

CONFIG_GENERIC_LOCKBREAK increases sizeof(spinlock_t) to 8 bytes.  It
leads to increase sizeof(struct page) by 4 bytes on 32-bit system if split
page table lock is in use, since page->ptl shares space in union with
longs and pointers.

Let's disable split page table lock on 32-bit systems with
GENERIC_LOCKBREAK enabled.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-15 09:32:13 +09:00
Tang Chen
c5320926e3 mem-hotplug: introduce movable_node boot option
The hot-Pluggable field in SRAT specifies which memory is hotpluggable.
As we mentioned before, if hotpluggable memory is used by the kernel, it
cannot be hot-removed.  So memory hotplug users may want to set all
hotpluggable memory in ZONE_MOVABLE so that the kernel won't use it.

Memory hotplug users may also set a node as movable node, which has
ZONE_MOVABLE only, so that the whole node can be hot-removed.

But the kernel cannot use memory in ZONE_MOVABLE.  By doing this, the
kernel cannot use memory in movable nodes.  This will cause NUMA
performance down.  And other users may be unhappy.

So we need a way to allow users to enable and disable this functionality.
In this patch, we introduce movable_node boot option to allow users to
choose to not to consume hotpluggable memory at early boot time and later
we can set it as ZONE_MOVABLE.

To achieve this, the movable_node boot option will control the memblock
allocation direction.  That said, after memblock is ready, before SRAT is
parsed, we should allocate memory near the kernel image as we explained in
the previous patches.  So if movable_node boot option is set, the kernel
does the following:

1. After memblock is ready, make memblock allocate memory bottom up.
2. After SRAT is parsed, make memblock behave as default, allocate memory
   top down.

Users can specify "movable_node" in kernel commandline to enable this
functionality.  For those who don't use memory hotplug or who don't want
to lose their NUMA performance, just don't specify anything.  The kernel
will work as before.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Suggested-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:09 +09:00
Geert Uytterhoeven
18f6533277 mm/Kconfig: Grammar s/an/a/
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-14 15:37:58 +02:00
Nathan Fontenot
f7e3334a6b powerpc: Fix memory hotplug with sparse vmemmap
Previous commit 46723bfa540... introduced a new config option
HAVE_BOOTMEM_INFO_NODE that ended up breaking memory hot-remove for ppc
when sparse vmemmap is not defined.

This patch defines HAVE_BOOTMEM_INFO_NODE for ppc and adds the call to
register_page_bootmem_info_node. Without this we get a BUG_ON for memory
hot remove in put_page_bootmem().

This also adds a stub for register_page_bootmem_memmap to allow ppc to build
with sparse vmemmap defined. Leaving this as a stub is fine since the same
vmemmap addresses are also handled in vmemmap_populate and as such are
properly mapped.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org> [v3.9+]
2013-10-03 17:21:38 +10:00
Chen Gang
de32a8177f mm/Kconfig: add MMU dependency for MIGRATION.
MIGRATION must depend on MMU, or allmodconfig for the nommu sh
architecture fails to build:

    CC      mm/migrate.o
  mm/migrate.c: In function 'remove_migration_pte':
  mm/migrate.c:134:3: error: implicit declaration of function 'pmd_trans_huge' [-Werror=implicit-function-declaration]
     if (pmd_trans_huge(*pmd))
     ^
  mm/migrate.c:149:2: error: implicit declaration of function 'is_swap_pte' [-Werror=implicit-function-declaration]
    if (!is_swap_pte(pte))
    ^
  ...

Also let CMA depend on MMU, or when NOMMU, if we select CMA, it will
select MIGRATION by force.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:03 -07:00
Alexander Graf
bf550fc93d Merge remote-tracking branch 'origin/next' into kvm-ppc-next
Conflicts:
	mm/Kconfig

CMA DMA split and ZSWAP introduction were conflicting, fix up manually.
2013-08-29 00:41:59 +02:00
Seth Jennings
2b2811178e zswap: add to mm/
zswap is a thin backend for frontswap that takes pages that are in the
process of being swapped out and attempts to compress them and store
them in a RAM-based memory pool.  This can result in a significant I/O
reduction on the swap device and, in the case where decompressing from
RAM is faster than reading from the swap device, can also improve
workload performance.

It also has support for evicting swap pages that are currently
compressed in zswap to the swap device on an LRU(ish) basis.  This
functionality makes zswap a true cache in that, once the cache is full,
the oldest pages can be moved out of zswap to the swap device so newer
pages can be compressed and stored in zswap.

This patch adds the zswap driver to mm/

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Jenifer Hopper <jhopper@us.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10 18:11:34 -07:00
Seth Jennings
4e2e2770b1 zbud: add to mm/
zbud is an special purpose allocator for storing compressed pages.  It
is designed to store up to two compressed pages per physical page.
While this design limits storage density, it has simple and
deterministic reclaim properties that make it preferable to a higher
density approach when reclaim will be used.

zbud works by storing compressed pages, or "zpages", together in pairs
in a single memory page called a "zbud page".  The first buddy is "left
justifed" at the beginning of the zbud page, and the last buddy is
"right justified" at the end of the zbud page.  The benefit is that if
either buddy is freed, the freed buddy space, coalesced with whatever
slack space that existed between the buddies, results in the largest
possible free region within the zbud page.

zbud also provides an attractive lower bound on density.  The ratio of
zpages to zbud pages can not be less than 1.  This ensures that zbud can
never "do harm" by using more pages to store zpages than the
uncompressed zpages would have used on their own.

This implementation is a rewrite of the zbud allocator internally used
by zcache in the driver/staging tree.  The rewrite was necessary to
remove some of the zcache specific elements that were ingrained
throughout and provide a generic allocation interface that can later be
used by zsmalloc and others.

This patch adds zbud to mm/ for later use by zswap.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Robert Jennings <rcj@linux.vnet.ibm.com>
Cc: Jenifer Hopper <jhopper@us.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Joe Perches <joe@perches.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-10 18:11:34 -07:00
Alexander Graf
20f7462aac Merge remote-tracking branch 'cmadma/for-v3.12-cma-dma' into kvm-ppc-next
Add prerequisite patch for CMA RMA allocation patches
2013-07-08 16:16:56 +02:00
Pavel Emelyanov
0f8975ec4d mm: soft-dirty bits for user memory changes tracking
The soft-dirty is a bit on a PTE which helps to track which pages a task
writes to.  In order to do this tracking one should

  1. Clear soft-dirty bits from PTEs ("echo 4 > /proc/PID/clear_refs)
  2. Wait some time.
  3. Read soft-dirty bits (55'th in /proc/PID/pagemap2 entries)

To do this tracking, the writable bit is cleared from PTEs when the
soft-dirty bit is.  Thus, after this, when the task tries to modify a
page at some virtual address the #PF occurs and the kernel sets the
soft-dirty bit on the respective PTE.

Note, that although all the task's address space is marked as r/o after
the soft-dirty bits clear, the #PF-s that occur after that are processed
fast.  This is so, since the pages are still mapped to physical memory,
and thus all the kernel does is finds this fact out and puts back
writable, dirty and soft-dirty bits on the PTE.

Another thing to note, is that when mremap moves PTEs they are marked
with soft-dirty as well, since from the user perspective mremap modifies
the virtual memory at mremap's new address.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:26 -07:00
Aneesh Kumar K.V
f825c736e7 mm/cma: Move dma contiguous changes into a seperate config
We want to use CMA for allocating hash page table and real mode area for
PPC64. Hence move DMA contiguous related changes into a seperate config
so that ppc64 can enable CMA without requiring DMA contiguous.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[removed defconfig changes]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2013-07-02 10:08:22 +02:00
Stephen Rothwell
40b313608a Finally eradicate CONFIG_HOTPLUG
Ever since commit 45f035ab9b ("CONFIG_HOTPLUG should be always on"),
it has been basically impossible to build a kernel with CONFIG_HOTPLUG
turned off.  Remove all the remaining references to it.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03 14:20:18 -07:00
Vinayak Menon
9ca24e2e19 mmKconfig: add an option to disable bounce
There are times when HIGHMEM is enabled, but we don't prefer
CONFIG_BOUNCE to be enabled.  CONFIG_BOUNCE can reduce the block device
throughput, and this is not ideal for machines where we don't gain much
by enabling it.  So provide an option to deselect CONFIG_BOUNCE.  The
observation was made while measuring eMMC throughput using iozone on an
ARM device with 1GB RAM.

Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:40 -07:00
Stephen Rothwell
4febd95a8a Select VIRT_TO_BUS directly where needed
In commit 887cbce0ad ("arch Kconfig: centralise ARCH_NO_VIRT_TO_BUS")
I introduced the config sybmol HAVE_VIRT_TO_BUS and selected that where
needed.  I am not sure what I was thinking.  Instead, just directly
select VIRT_TO_BUS where it is needed.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-12 11:16:40 -07:00
Stephen Rothwell
887cbce0ad arch Kconfig: centralise CONFIG_ARCH_NO_VIRT_TO_BUS
Change it to CONFIG_HAVE_VIRT_TO_BUS and set it in all architecures
that already provide virt_to_bus().

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: H Hartley Sweeten <hartleys@visionengravers.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:23 -08:00
Yasuaki Ishimatsu
46723bfa54 memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap
For removing memmap region of sparse-vmemmap which is allocated bootmem,
memmap region of sparse-vmemmap needs to be registered by
get_page_bootmem().  So the patch searches pages of virtual mapping and
registers the pages by get_page_bootmem().

NOTE: register_page_bootmem_memmap() is not implemented for ia64,
      ppc, s390, and sparc.  So introduce CONFIG_HAVE_BOOTMEM_INFO_NODE
      and revert register_page_bootmem_info_node() when platform doesn't
      support it.

      It's implemented by adding a new Kconfig option named
      CONFIG_HAVE_BOOTMEM_INFO_NODE, which will be automatically selected
      by memory-hotplug feature fully supported archs(currently only on
      x86_64).

      Since we have 2 config options called MEMORY_HOTPLUG and
      MEMORY_HOTREMOVE used for memory hot-add and hot-remove separately,
      and codes in function register_page_bootmem_info_node() are only
      used for collecting infomation for hot-remove, so reside it under
      MEMORY_HOTREMOVE.

      Besides page_isolation.c selected by MEMORY_ISOLATION under
      MEMORY_HOTPLUG is also such case, move it too.

[mhocko@suse.cz: put register_page_bootmem_memmap inside CONFIG_MEMORY_HOTPLUG_SPARSE]
[linfeng@cn.fujitsu.com: introduce CONFIG_HAVE_BOOTMEM_INFO_NODE and revert register_page_bootmem_info_node()]
[mhocko@suse.cz: remove the arch specific functions without any implementation]
[linfeng@cn.fujitsu.com: mm/Kconfig: move auto selects from MEMORY_HOTPLUG to MEMORY_HOTREMOVE as needed]
[rientjes@google.com: fix defined but not used warning]
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Wu Jianguo <wujianguo@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com>
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>
2013-02-23 17:50:12 -08:00
Linus Torvalds
7c2db36e73 Merge branch 'akpm' (incoming from Andrew)
Merge misc patches from Andrew Morton:

 - Florian has vanished so I appear to have become fbdev maintainer
   again :(

 - Joel and Mark are distracted to welcome to the new OCFS2 maintainer

 - The backlight queue

 - Small core kernel changes

 - lib/ updates

 - The rtc queue

 - Various random bits

* akpm: (164 commits)
  rtc: rtc-davinci: use devm_*() functions
  rtc: rtc-max8997: use devm_request_threaded_irq()
  rtc: rtc-max8907: use devm_request_threaded_irq()
  rtc: rtc-da9052: use devm_request_threaded_irq()
  rtc: rtc-wm831x: use devm_request_threaded_irq()
  rtc: rtc-tps80031: use devm_request_threaded_irq()
  rtc: rtc-lp8788: use devm_request_threaded_irq()
  rtc: rtc-coh901331: use devm_clk_get()
  rtc: rtc-vt8500: use devm_*() functions
  rtc: rtc-tps6586x: use devm_request_threaded_irq()
  rtc: rtc-imxdi: use devm_clk_get()
  rtc: rtc-cmos: use dev_warn()/dev_dbg() instead of printk()/pr_debug()
  rtc: rtc-pcf8583: use dev_warn() instead of printk()
  rtc: rtc-sun4v: use pr_warn() instead of printk()
  rtc: rtc-vr41xx: use dev_info() instead of printk()
  rtc: rtc-rs5c313: use pr_err() instead of printk()
  rtc: rtc-at91rm9200: use dev_dbg()/dev_err() instead of printk()/pr_debug()
  rtc: rtc-rs5c372: use dev_dbg()/dev_warn() instead of printk()/pr_debug()
  rtc: rtc-ds2404: use dev_err() instead of printk()
  rtc: rtc-efi: use dev_err()/dev_warn()/pr_err() instead of printk()
  ...
2013-02-21 17:38:49 -08:00
Darrick J. Wong
ffecfd1a72 block: optionally snapshot page contents to provide stable pages during write
This provides a band-aid to provide stable page writes on jbd without
needing to backport the fixed locking and page writeback bit handling
schemes of jbd2.  The band-aid works by using bounce buffers to snapshot
page contents instead of waiting.

For those wondering about the ext3 bandage -- fixing the jbd locking
(which was done as part of ext4dev years ago) is a lot of surgery, and
setting PG_writeback on data pages when we actually hold the page lock
dropped ext3 performance by nearly an order of magnitude.  If we're
going to migrate iscsi and raid to use stable page writes, the
complaints about high latency will likely return.  We might as well
centralize their page snapshotting thing to one place.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21 17:22:20 -08:00
Kees Cook
a8826eeb71 mm: remove depends on CONFIG_EXPERIMENTAL
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Andrew Morton <akpm@linux-foundation.org>
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Jan Beulich <JBeulich@novell.com>
CC: Mel Gorman <mel@csn.ul.ie>
CC: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17 12:11:27 -08:00
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