sparse: Undef __compiletime_{warning,error} if __CHECKER__ is defined

sparse can't parse warning and error attribute.  then they should be
hidden from sparse.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sparse: define __must_be_array() for __CHECKER__

commit c5e631cf65f ("ARRAY_SIZE: check for type") added __must_be_array().
But sparse can't parse this gcc extention.

Now make C=2 makes following sparse errors a lot.

  kernel/futex.c:2699:25: error: No right hand side of '+'-expression

Because __must_be_array() is used for ARRAY_SIZE() macro and it is
used very widely.

This patch fixes it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sparse: define dummy BUILD_BUG_ON definition for sparse

BUILD_BUG_ON() causes a syntax error to detect coding errors.  So it
causes sparse to detect an error too.  This reduces sparse's usefulness.

This patch makes a dummy BUILD_BUG_ON() definition for sparse.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/calibrate.c: fix for critical bogoMIPS intermittent calculation failure

A fix to the TSC (Time Stamp Counter) based bogoMIPS calculation used on
secondary CPUs which has two faults:

1: Not handling wrapping of the lower 32 bits of the TSC counter on
   32bit kernel - perhaps TSC is not reset by a warm reset?

2: TSC and Jiffies are no incrementing together properly.  Either
   jiffies increment too quickly or Time Stamp Counter isn't incremented
   in during an SMI but the real time clock is and jiffies are
   incremented.

Case 1 can result in a factor of 16 too large a value which makes udelay()
values too small and can cause mysterious driver errors.  Case 2 appears
to give smaller 10-15% errors after averaging but enough to cause
occasional failures on my own board

I have tested this code on my own branch and attach patch suitable for
current kernel code.  See below for examples of the failures and how the
fix handles these situations now.

I reported this issue earlier here:
     Intermittent problem with BogoMIPs calculation on Intel AP CPUs -
http://marc.info/?l=linux-kernel&m=129947246316875&w=4

I suspect this issue has been seen by others but as it is intermittent and
bogoMIPS for secondary CPUs are no longer printed out it might have been
difficult to identify this as the cause.  Perhaps these unresolved issues,
although quite old, might be relevant as possibly this fault has been
around for a while.  In particular Case 1 may only be relevant to 32bit
kernels on newer HW (most people run 64bit kernels?).  Case 2 is less
dramatic since the earlier fix in this area and also intermittent.

   Re: bogomips discrepancy on Intel Core2 Quad CPU -
http://marc.info/?l=linux-kernel&m=118929277524298&w=4
   slow system and bogus bogomips  -
http://marc.info/?l=linux-kernel&m=116791286716107&w=4
   Re: Re: [RFC-PATCH] clocksource: update lpj if clocksource has -
http://marc.info/?l=linux-kernel&m=128952775819467&w=4

This issue is masked a little by commit feae3203d711db0a ("timers, init:
Limit the number of per cpu calibration bootup messages") which only
prints out the first bogoMIPS value making it much harder to notice other
values differing.  Perhaps it should be changed to only suppress them when
they are similar values?

Here are some outputs showing faults occurring and the new code handling
them properly.  See my earlier message for examples of the original
failure.

    Case 1:   A Time Stamp Counter wrap:
...
Calibrating delay loop (skipped), value calculated using timer
frequency.. 6332.70 BogoMIPS (lpj=31663540)
....
calibrate_delay_direct() timer_rate_max=31666493
timer_rate_min=31666151 pre_start=4170369255 pre_end=4202035539
calibrate_delay_direct() timer_rate_max=2425955274
timer_rate_min=2425954941 pre_start=4265368533 pre_end=2396356387
calibrate_delay_direct() ignoring timer_rate as we had a TSC wrap
around start=4265368581 >=post_end=2396356511
calibrate_delay_direct() timer_rate_max=31666274
timer_rate_min=31665942 pre_start=2440373374 pre_end=2472039515
calibrate_delay_direct() timer_rate_max=31666492
timer_rate_min=31666160 pre_start=2535372139 pre_end=2567038422
calibrate_delay_direct() timer_rate_max=31666455
timer_rate_min=31666207 pre_start=2630371084 pre_end=2662037415
Calibrating delay using timer specific routine.. 6333.28 BogoMIPS (lpj=31666428)
Total of 2 processors activated (12665.99 BogoMIPS).
....

    Case 2:  Some thing (presumably the SMM interrupt?) causing the
very low increase in TSC counter for the DELAY_CALIBRATION_TICKS
increase in jiffies
...
Calibrating delay loop (skipped), value calculated using timer
frequency.. 6333.25 BogoMIPS (lpj=31666270)
...
calibrate_delay_direct() timer_rate_max=31666483
timer_rate_min=31666074 pre_start=4199536526 pre_end=4231202809
calibrate_delay_direct() timer_rate_max=864348 timer_rate_min=864016
pre_start=2405343672 pre_end=2406207897
calibrate_delay_direct() timer_rate_max=31666483
timer_rate_min=31666179 pre_start=2469540464 pre_end=2501206823
calibrate_delay_direct() timer_rate_max=31666511
timer_rate_min=31666122 pre_start=2564539400 pre_end=2596205712
calibrate_delay_direct() timer_rate_max=31666084
timer_rate_min=31665685 pre_start=2659538782 pre_end=2691204657
calibrate_delay_direct() dropping min bogoMips estimate 1 = 864348
Calibrating delay using timer specific routine.. 6333.27 BogoMIPS (lpj=31666390)
Total of 2 processors activated (12666.53 BogoMIPS).
...

After 70 boots I saw 2 variations <1% slip through

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix straggly printk mess]
Signed-off-by: Andrew Worsley <amworsley@gmail.com>
Reviewed-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xattr.h: expose string defines to userspace

af4f136056c9 ("security: move LSM xattrnames to xattr.h") moved the
XATTR_CAPS_SUFFIX define from capability.h to xattr.h.  This makes sense
except it was previously exports to userspace but xattr.h does not export
it to userspace.  This patch exports these headers to userspace to fix the
ABI regression.

There is some slight possibility that this will cause problems in other
applications which used these #defines differently (wrongly) and I could
JUST export the capabilities xattr name that we broke.  Does anyonehave an
idea how exposing these headers could cause a problem?

Below is what is being exposed to userspace, included here since it isn't
clear exactly what is going to be made available from the patch.

/* Namespaces */
#define XATTR_OS2_PREFIX "os2."
#define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)

#define XATTR_SECURITY_PREFIX   "security."
#define XATTR_SECURITY_PREFIX_LEN (sizeof (XATTR_SECURITY_PREFIX) - 1)

#define XATTR_SYSTEM_PREFIX "system."
#define XATTR_SYSTEM_PREFIX_LEN (sizeof (XATTR_SYSTEM_PREFIX) - 1)

#define XATTR_TRUSTED_PREFIX "trusted."
#define XATTR_TRUSTED_PREFIX_LEN (sizeof (XATTR_TRUSTED_PREFIX) - 1)

#define XATTR_USER_PREFIX "user."
#define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)

/* Security namespace */
#define XATTR_SELINUX_SUFFIX "selinux"
#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX

#define XATTR_SMACK_SUFFIX "SMACK64"
#define XATTR_SMACK_IPIN "SMACK64IPIN"
#define XATTR_SMACK_IPOUT "SMACK64IPOUT"
#define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX
#define XATTR_NAME_SMACKIPIN    XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN
#define XATTR_NAME_SMACKIPOUT   XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT

#define XATTR_CAPS_SUFFIX "capability"
#define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX

Reported-by: Ozan Çaglayan <ozan@pardus.org.tr>
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: Mimi Zohar <zohar@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitmap, irq: add smp_affinity_list interface to /proc/irq

Manually adjusting the smp_affinity for IRQ's becomes unwieldy when the
cpu count is large.

Setting smp affinity to cpus 256 to 263 would be:

echo 000000ff,00000000,00000000,00000000,00000000,00000000,00000000,00000000 > smp_affinity

instead of:

echo 256-263 > smp_affinity_list

Think about what it looks like for cpus around say, 4088 to 4095.

We already have many alternate "list" interfaces:

/sys/devices/system/cpu/cpuX/indexY/shared_cpu_list
/sys/devices/system/cpu/cpuX/topology/thread_siblings_list
/sys/devices/system/cpu/cpuX/topology/core_siblings_list
/sys/devices/system/node/nodeX/cpulist
/sys/devices/pci***/***/local_cpulist

Add a companion interface, smp_affinity_list to use cpu lists instead of
cpu maps.  This conforms to other companion interfaces where both a map
and a list interface exists.

This required adding a bitmap_parselist_user() function in a manner
similar to the bitmap_parse_user() function.

[akpm@linux-foundation.org: make __bitmap_parselist() static]
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fscache: remove dead code under CONFIG_WORKQUEUE_DEBUGFS

There is no CONFIG_WORKQUEUE_DEBUGFS any more, so this code is dead.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86: remove 32-bit versions of readq()/writeq()

The presense of a writeq() implementation on 32-bit x86 that splits the
64-bit write into two 32-bit writes turns out to break the mpt2sas driver
(and in general is risky for drivers as was discussed in
<http://lkml.kernel.org/r/adaab6c1h7c.fsf@cisco.com>).  To fix this,
revert 2c5643b1c5c7 ("x86: provide readq()/writeq() on 32-bit too") and
follow-on cleanups.

This unfortunately leads to pushing non-atomic definitions of readq() and
write() to various x86-only drivers that in the meantime started using the
definitions in the x86 version of <asm/io.h>.  However as discussed
exhaustively, this is actually the right thing to do, because the right
way to split a 64-bit transaction is hardware dependent and therefore
belongs in the hardware driver (eg mpt2sas needs a spinlock to make sure
no other accesses occur in between the two halves of the access).

Build tested on 32- and 64-bit x86 allmodconfig.

Link: http://lkml.kernel.org/r/x86-32-writeq-is-broken@mdm.bga.com
Acked-by: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Acked-by: James Bottomley <James.Bottomley@parallels.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Remove unused PROC_CHANGE_PENALTY constant

This constant hasn't been used since before the git era (2.6.12) and thus
can be dropped.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Richard Weinberger <richard@nod.at>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/c2port.h: remove wrong and never used macros

The macro to_class_dev() uses the deprecated structure class_device, and
the c2port_device has no member named class in the definition of the macro
to_c2port_device.

Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com>
Cc: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ulimit: raise default hard ulimit on number of files to 4096

Apps are increasingly using more than 1024 file descriptors.  See
discussion in several distro bug trackers, e.g.  BugLink:
http://bugs.launchpad.net/bugs/663090
https://issues.rpath.com/browse/RPL-2054

You don't want to raise the default soft limit, since that might break
apps that use select(), but it's safe to raise the default hard limit;
that way, apps that know they need lots of file descriptors can raise
their soft limit without needing root, and without user intervention.

Ubuntu is doing this with a kernel change because they have a policy of
not changing kernel defaults in userland.

While 4096 might not be enough for *all* apps, it seems to be plenty for
the apps I've seen lately that are unhappy with 1024.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Cc: Dan Kegel <dank@kegel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: fix crash while os_dump_core()

os_dump_core() emits SIGTERM to terminate all UML processes.  Kernel
threads have to exit on SIGTERM instead of calling last_ditch_exit().
Multiple calls to last_ditch_exit() can cause a crash.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: include linux/prefetch.h

Fix build failures on UML.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: print info about fatal segfaults

Print a short info about fatal segfaults like other archs do.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: add ucast ethernet transport

The ucast transport is similar to the mcast transport (and, in fact,
shares most of its code), only it uses UDP unicast to move packets.

Obviously this is only useful for point-to-point connections between
virtual ethernet devices.

Signed-off-by: Nolan Leake <nolan@cumulusnetworks.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: add earlyprintk support

User Mode Linux can also benefit from earlyprintk.  UML's earlyprintk
writes kernel messages directly to stdout.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: remove SIGHUP handler

The UML kernel ignores SIGHUP anyway.  This handler is in vain.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: fix UML_LIB_PATH

UML_LIB_PATH is hardcoded to /usr/lib/uml/, on 64bit systems UML_LIB_PATH
needs to be /usr/lib64/uml/.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cris: convert old cpumask API into new one

Adapt to the new API.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Thiago Farina <tfransosi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mn10300: convert old cpumask API into new one

Adapt to the new API.

We plan to remove old cpumask APIs later.  Thus this patch converts them
into the new one.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

alpha: hook up gpiolib support

Allow people to use gpiolib on Alpha if they want to, mostly for build
coverage.  The header is a stright copy of that for Microblaze, which in
turn was taken from PowerPC.

[akpm@linux-foundation.org: define GENERIC_GPIO]
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

alpha: replace with new cpumask APIs

We plan to remove cpu_xx() old APIs.  Thus convert them.  This patch has
no functional change.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nommu: add page alignment to mmap

Currently on nommu arch mmap(),mremap() and munmap() doesn't do
page_align() which isn't consist with mmu arch and cause some issues.

First, some drivers' mmap() function depends on vma->vm_end - vma->start
is page aligned which is true on mmu arch but not on nommu.  eg: uvc
camera driver.

Second munmap() may return -EINVAL[split file] error in cases when end is
not page aligned(passed into from userspace) but vma->vm_end is aligned
dure to split or driver's mmap() ops.

Add page alignment to fix those issues.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: batch activate_page() to reduce lock contention

The zone->lru_lock is heavily contented in workload where activate_page()
is frequently used.  We could do batch activate_page() to reduce the lock
contention.  The batched pages will be added into zone list when the pool
is full or page reclaim is trying to drain them.

For example, in a 4 socket 64 CPU system, create a sparse file and 64
processes, processes shared map to the file.  Each process read access the
whole file and then exit.  The process exit will do unmap_vmas() and cause
a lot of activate_page() call.  In such workload, we saw about 58% total
time reduction with below patch.  Other workloads with a lot of
activate_page also benefits a lot too.

Andrew Morton suggested activate_page() and putback_lru_pages() should
follow the same path to active pages, but this is hard to implement (see
commit 7a608572a282a ("Revert "mm: batch activate_page() to reduce lock
contention")).  On the other hand, do we really need putback_lru_pages()
to follow the same path?  I tested several FIO/FFSB benchmark (about 20
scripts for each benchmark) in 3 machines here from 2 sockets to 4
sockets.  My test doesn't show anything significant with/without below
patch (there is slight difference but mostly some noise which we found
even without below patch before).  Below patch basically returns to the
same as my first post.

I tested some microbenchmarks:
  case-anon-cow-rand-mt         0.58%
  case-anon-cow-rand           -3.30%
  case-anon-cow-seq-mt         -0.51%
  case-anon-cow-seq            -5.68%
  case-anon-r-rand-mt           0.23%
  case-anon-r-rand              0.81%
  case-anon-r-seq-mt           -0.71%
  case-anon-r-seq              -1.99%
  case-anon-rx-rand-mt          2.11%
  case-anon-rx-seq-mt           3.46%
  case-anon-w-rand-mt          -0.03%
  case-anon-w-rand             -0.50%
  case-anon-w-seq-mt           -1.08%
  case-anon-w-seq              -0.12%
  case-anon-wx-rand-mt         -5.02%
  case-anon-wx-seq-mt          -1.43%
  case-fork                     1.65%
  case-fork-sleep              -0.07%
  case-fork-withmem             1.39%
  case-hugetlb                 -0.59%
  case-lru-file-mmap-read-mt   -0.54%
  case-lru-file-mmap-read       0.61%
  case-lru-file-mmap-read-rand -2.24%
  case-lru-file-readonce       -0.64%
  case-lru-file-readtwice     -11.69%
  case-lru-memcg               -1.35%
  case-mmap-pread-rand-mt       1.88%
  case-mmap-pread-rand        -15.26%
  case-mmap-pread-seq-mt        0.89%
  case-mmap-pread-seq         -69.72%
  case-mmap-xread-rand-mt       0.71%
  case-mmap-xread-seq-mt        0.38%

The most significent are:
  case-lru-file-readtwice     -11.69%
  case-mmap-pread-rand        -15.26%
  case-mmap-pread-seq         -69.72%

which use activate_page a lot.  others are basically variations because
each run has slightly difference.

In UP case, 'size mm/swap.o'
before the two patches:
   text    data     bss     dec     hex filename
   6466     896       4    7366    1cc6 mm/swap.o
after the two patches:
   text    data     bss     dec     hex filename
   6343     896       4    7243    1c4b mm/swap.o

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

asm-generic/cacheflush.h: flush icache when copying to user pages

The copy_to_user_page() function is supposed to flush the icache on the
memory that was written, but the current asm-generic version lacks that
logic.  While normally it isn't a big deal as the asm-generic version of
icache flushing is a stub, it is a deal for ports that want to use the
asm-generic version as a baseline and then overlay its own specific parts
(like icache flushing).

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c: prevent unending loop in __alloc_pages_slowpath()

I believe I found a problem in __alloc_pages_slowpath, which allows a
process to get stuck endlessly looping, even when lots of memory is
available.

Running an I/O and memory intensive stress-test I see a 0-order page
allocation with __GFP_IO and __GFP_WAIT, running on a system with very
little free memory.  Right about the same time that the stress-test gets
killed by the OOM-killer, the utility trying to allocate memory gets stuck
in __alloc_pages_slowpath even though most of the systems memory was freed
by the oom-kill of the stress-test.

The utility ends up looping from the rebalance label down through the
wait_iff_congested continiously.  Because order=0,
__alloc_pages_direct_compact skips the call to get_page_from_freelist.
Because all of the reclaimable memory on the system has already been
reclaimed, __alloc_pages_direct_reclaim skips the call to
get_page_from_freelist.  Since there is no __GFP_FS flag, the block with
__alloc_pages_may_oom is skipped.  The loop hits the wait_iff_congested,
then jumps back to rebalance without ever trying to
get_page_from_freelist.  This loop repeats infinitely.

The test case is pretty pathological.  Running a mix of I/O stress-tests
that do a lot of fork() and consume all of the system memory, I can pretty
reliably hit this on 600 nodes, in about 12 hours.  32GB/node.

Signed-off-by: Andrew Barry <abarry@cray.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Rik van Riel<riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: add SECTION_ALIGN_UP() and SECTION_ALIGN_DOWN() macro

Add SECTION_ALIGN_UP() and SECTION_ALIGN_DOWN() macro which aligns given
pfn to upper section and lower section boundary accordingly.

Required for the latest memory hotplug support for the Xen balloon driver.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memsw: remove noswapaccount kernel parameter

The noswapaccount parameter has been deprecated since 2.6.38 without any
complaints from users so we can remove it.  swapaccount=0|1 can be used
instead.

As we are removing the parameter we can also clean up swapaccount because
it doesn't have to accept an empty string anymore (to match noswapaccount)
and so we can push = into __setup macro rather than checking "=1" resp.
"=0" strings

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Hiroyuki Kamezawa <kamezawa.hiroyuki@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc: allocate storage for numa_maps statistics once

In show_numa_map() we collect statistics into a numa_maps structure.
Since the number of NUMA nodes can be very large, this structure is not a
candidate for stack allocation.

Instead of going thru a kmalloc()+kfree() cycle each time show_numa_map()
is invoked, perform the allocation just once when /proc/pid/numa_maps is
opened.

Performing the allocation when numa_maps is opened, and thus before a
reference to the target tasks mm is taken, eliminates a potential
stalemate condition in the oom-killer as originally described by Hugh
Dickins:

  ... imagine what happens if the system is out of memory, and the mm
  we're looking at is selected for killing by the OOM killer: while
  we wait in __get_free_page for more memory, no memory is freed
  from the selected mm because it cannot reach exit_mmap while we hold
  that reference.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc: make struct proc_maps_private truly private

Now that mm/mempolicy.c is no longer implementing /proc/pid/numa_maps
there is no need to export struct proc_maps_private to the world.  Move it
to fs/proc/internal.h instead.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: proc: move show_numa_map() to fs/proc/task_mmu.c

Moving show_numa_map() from mempolicy.c to task_mmu.c solves several
issues.

  - Having the show() operation "miles away" from the corresponding
    seq_file iteration operations is a maintenance burden.

  - The need to export ad hoc info like struct proc_maps_private is
    eliminated.

  - The implementation of show_numa_map() can be improved in a simple
    manner by cooperating with the other seq_file operations (start,
    stop, etc) -- something that would be messy to do without this
    change.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: declare mpol_to_str() when CONFIG_TMPFS=n

When CONFIG_TMPFS=n mpol_to_str() is not declared in mempolicy.h.
However, in the NUMA case, the definition is always compiled.

Since it is not strictly true that tmpfs is the only client, and since the
symbol was always lurking around anyways, export mpol_to_str()
unconditionally.  Furthermore, this will allow us to move show_numa_map()
out of mempolicy.c and into the procfs subsystem.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove check_huge_range()

This function has been superseded by gather_hugetbl_stats() and is no
longer needed.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: make gather_stats() type-safe and remove forward declaration

Improve the prototype of gather_stats() to take a struct numa_maps as
argument instead of a generic void *.  Update all callers to make the
required type explicit.

Since gather_stats() is not needed before its definition and is scheduled
to be moved out of mempolicy.c the declaration is removed as well.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove MPOL_MF_STATS

Mapping statistics in a NUMA environment is now computed using the generic
walk_page_range() logic.  Remove the old/equivalent functionality.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use walk_page_range() instead of custom page table walking code

Converting show_numa_map() to use the generic routine decouples the
function from mempolicy.c, allowing it to be moved out of the mm subsystem
and into fs/proc.

Also, include KSM pages in /proc/pid/numa_maps statistics.  The pagewalk
logic implemented by check_pte_range() failed to account for such pages as
they were not applicable to the page migration case.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: export get_vma_policy()

In commit 48fce3429d ("mempolicies: unexport get_vma_policy()")
get_vma_policy() was marked static as all clients were local to
mempolicy.c.

However, the decision to generate /proc/pid/numa_maps in the numa memory
policy code and outside the procfs subsystem introduces an artificial
interdependency between the two systems.  Exporting get_vma_policy() once
again is the first step to clean up this interdependency.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove last trace of shmem_get_unmapped_area

Remove noMMU declaration of shmem_get_unmapped_area() from mm.h: it fell
out of use in 2.6.21 and ceased to exist in 2.6.29.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tmpfs: implement generic xattr support

Implement generic xattrs for tmpfs filesystems.  The Feodra project, while
trying to replace suid apps with file capabilities, realized that tmpfs,
which is used on the build systems, does not support file capabilities and
thus cannot be used to build packages which use file capabilities.  Xattrs
are also needed for overlayfs.

The xattr interface is a bit odd.  If a filesystem does not implement any
{get,set,list}xattr functions the VFS will call into some random LSM hooks
and the running LSM can then implement some method for handling xattrs.
SELinux for example provides a method to support security.selinux but no
other security.* xattrs.

As it stands today when one enables CONFIG_TMPFS_POSIX_ACL tmpfs will have
xattr handler routines specifically to handle acls.  Because of this tmpfs
would loose the VFS/LSM helpers to support the running LSM.  To make up
for that tmpfs had stub functions that did nothing but call into the LSM
hooks which implement the helpers.

This new patch does not use the LSM fallback functions and instead just
implements a native get/set/list xattr feature for the full security.* and
trusted.* namespace like a normal filesystem.  This means that tmpfs can
now support both security.selinux and security.capability, which was not
previously possible.

The basic implementation is that I attach a:

struct shmem_xattr {
struct list_head list; /* anchored by shmem_inode_info->xattr_list */
char *name;
size_t size;
char value[0];
};

Into the struct shmem_inode_info for each xattr that is set.  This
implementation could easily support the user.* namespace as well, except
some care needs to be taken to prevent large amounts of unswappable memory
being allocated for unprivileged users.

[mszeredi@suse.cz: new config option, suport trusted.*, support symlinks]
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Hugh Dickins <hughd@google.com>
Tested-by: Jordi Pujol <jordipujolp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock/nobootmem: remove unneeded code from alloc_bootmem_node_high()

The bootmem wrapper with memblock supports top-down now, so we no longer
need this trick.

Signed-off-by: Yinghai LU <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Olaf Hering <olaf@aepfle.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock/nobootmem: allow alloc_bootmem() to take 0 as low limit

The bootmem wrapper with memblock supports top-down now, so we do not need
to set the low limit to __pa(MAX_DMA_ADDRESS).

The logic should be: good to allocate above __pa(MAX_DMA_ADDRESS), but it
is ok if we can not find memory above 16M on system that has a small
amount of RAM.

Signed-off-by: Yinghai LU <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Olaf Hering <olaf@aepfle.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: delete non-atomic mm counter implementation

The problem with having two different types of counters is that developers
adding new code need to keep in mind whether it's safe to use both the
atomic and non-atomic implementations.  For example, when adding new
callers of the *_mm_counter() functions a developer needs to ensure that
those paths are always executed with page_table_lock held, in case we're
using the non-atomic implementation of mm counters.

Hugh Dickins introduced the atomic mm counters in commit f412ac08c986
("[PATCH] mm: fix rss and mmlist locking").  When asked why he left the
non-atomic counters around he said,

  | The only reason was to avoid adding costly atomic operations into a
  | configuration that had no need for them there: the page_table_lock
  | sufficed.
  |
  | Certainly it would be simpler just to delete the non-atomic variant.
  |
  | And I think it's fair to say that any configuration on which we're
  | measuring performance to that degree (rather than "does it boot fast?"
  | type measurements), would already be going the split ptlocks route.

Removing the non-atomic counters eases the maintenance burden because
developers no longer have to mindful of the two implementations when using
*_mm_counter().

Note that all architectures provide a means of atomically updating
atomic_long_t variables, even if they have to revert to the generic
spinlock implementation because they don't support 64-bit atomic
instructions (see lib/atomic64.c).

Signed-off-by: Matt Fleming <matt.fleming@linux.intel.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fail GFP_DMA allocations when ZONE_DMA is not configured

The page allocator will improperly return a page from ZONE_NORMAL even
when __GFP_DMA is passed if CONFIG_ZONE_DMA is disabled.  The caller
expects DMA memory, perhaps for ISA devices with 16-bit address registers,
and may get higher memory resulting in undefined behavior.

This patch causes the page allocator to return NULL in such circumstances
with a warning emitted to the kernel log on the first occurrence.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>

mm: do not define PFN_SECTION_SHIFT if !CONFIG_SPARSEMEM

Do not define PFN_SECTION_SHIFT if !CONFIG_SPARSEMEM.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: pfn_to_section_nr()/section_nr_to_pfn() is valid only in CONFIG_SPARSEMEM context

pfn_to_section_nr()/section_nr_to_pfn() is valid only in CONFIG_SPARSEMEM
context.  Move it to proper place.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: enable set_page_section() only if CONFIG_SPARSEMEM and !CONFIG_SPARSEMEM_VMEMMAP

set_page_section() is meaningful only in CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP context.  Move it to proper place and amend
accordingly functions which are using it.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.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>

mm: remove dependency on CONFIG_FLATMEM from online_page()

online_pages() is only compiled for CONFIG_MEMORY_HOTPLUG_SPARSE, so there
is no need to support CONFIG_FLATMEM code within it.

This patch removes code that is never used.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.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>

mm: filter unevictable page out in deactivate_page()

It's pointless that deactive_page's operates on unevictable pages.  This
patch removes unnecessary overhead which might be a bit problem in case
that there are many unevictable page in system(ex, mprotect workload)

[akpm@linux-foundation.org: tidy up comment]
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.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>

readahead: trigger mmap sequential readahead on PG_readahead

Previously the mmap sequential readahead is triggered by updating
ra->prev_pos on each page fault and compare it with current page offset.

It costs dirtying the cache line on each _minor_ page fault.  So remove
the ra->prev_pos recording, and instead tag PG_readahead to trigger the
possible sequential readahead.  It's not only more simple, but also will
work more reliably and reduce cache line bouncing on concurrent page
faults on shared struct file.

In the mosbench exim benchmark which does multi-threaded page faults on
shared struct file, the ra->mmap_miss and ra->prev_pos updates are found
to cause excessive cache line bouncing on tmpfs, which actually disabled
readahead totally (shmem_backing_dev_info.ra_pages == 0).

So remove the ra->prev_pos recording, and instead tag PG_readahead to
trigger the possible sequential readahead.  It's not only more simple, but
also will work more reliably on concurrent reads on shared struct file.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Tested-by: Tim Chen <tim.c.chen@intel.com>
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

readahead: reduce unnecessary mmap_miss increases

The original INT_MAX is too large, reduce it to

- avoid unnecessarily dirtying/bouncing the cache line

- restore mmap read-around faster on changed access pattern

Background: in the mosbench exim benchmark which does multi-threaded page
faults on shared struct file, the ra->mmap_miss updates are found to cause
excessive cache line bouncing on tmpfs.  The ra state updates are needless
for tmpfs because it actually disabled readahead totally
(shmem_backing_dev_info.ra_pages == 0).

Tested-by: Tim Chen <tim.c.chen@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

readahead: return early when readahead is disabled

Reduce readahead overheads by returning early in do_sync_mmap_readahead().

tmpfs has ra_pages=0 and it can page fault really fast (not constraint by
IO if not swapping).

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Tested-by: Tim Chen <tim.c.chen@intel.com>
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vmscan: change shrinker API by passing shrink_control struct

Change each shrinker's API by consolidating the existing parameters into
shrink_control struct.  This will simplify any further features added w/o
touching each file of shrinker.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: fix warning]
[kosaki.motohiro@jp.fujitsu.com: fix up new shrinker API]
[akpm@linux-foundation.org: fix xfs warning]
[akpm@linux-foundation.org: update gfs2]
Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vmscan: change shrink_slab() interfaces by passing shrink_control

Consolidate the existing parameters to shrink_slab() into a new
shrink_control struct.  This is needed later to pass the same struct to
shrinkers.

Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

readahead: readahead page allocations are OK to fail

Pass __GFP_NORETRY|__GFP_NOWARN for readahead page allocations.

readahead page allocations are completely optional.  They are OK to fail
and in particular shall not trigger OOM on themselves.

Reported-by: Dave Young <hidave.darkstar@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: check if any page in a pageblock is reserved before marking it MIGRATE_RESERVE

This fixes a problem where the first pageblock got marked MIGRATE_RESERVE
even though it only had a few free pages.  eg, On current ARM port, The
kernel starts at offset 0x8000 to leave room for boot parameters, and the
memory is freed later.

This in turn caused no contiguous memory to be reserved and frequent
kswapd wakeups that emptied the caches to get more contiguous memory.

Unfortunatelly, ARM needs order-2 allocation for pgd (see
arm/mm/pgd.c#pgd_alloc()).  Therefore the issue is not minor nor easy
avoidable.

[kosaki.motohiro@jp.fujitsu.com: added some explanation]
[kosaki.motohiro@jp.fujitsu.com: add !pfn_valid_within() to check]
[minchan.kim@gmail.com: check end_pfn in pageblock_is_reserved]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

m32r, mm: set all online nodes in N_NORMAL_MEMORY

For m32r, N_NORMAL_MEMORY represents all nodes that have present memory
since it does not support HIGHMEM.  This patch sets the bit at the time
the node is initialized.

If N_NORMAL_MEMORY is not accurate, slub may encounter errors since it
uses this nodemask to setup per-cache kmem_cache_node data structures.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

alpha, mm: set all online nodes in N_NORMAL_MEMORY

For alpha, N_NORMAL_MEMORY represents all nodes that have present memory
since it does not support HIGHMEM.  This patch sets the bit at the time
the node is initialized.

If N_NORMAL_MEMORY is not accurate, slub may encounter errors since it
uses this nodemask to setup per-cache kmem_cache_node data structures.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: strictly require elevated page refcount in isolate_lru_page()

isolate_lru_page() must be called only with stable reference to the page,
this is what is written in the comment above it, this is reasonable.

current isolate_lru_page() users and its page extra reference sources:

 mm/huge_memory.c:
  __collapse_huge_page_isolate() - reference from pte

 mm/memcontrol.c:
  mem_cgroup_move_parent() - get_page_unless_zero()
  mem_cgroup_move_charge_pte_range() - reference from pte

 mm/memory-failure.c:
  soft_offline_page() - fixed, reference from get_any_page()
  delete_from_lru_cache() - reference from caller or get_page_unless_zero()
[ seems like there bug, because __memory_failure() can call
  page_action() for hpages tail, but it is ok for
  isolate_lru_page(), tail getted and not in lru]

 mm/memory_hotplug.c:
  do_migrate_range() - fixed, get_page_unless_zero()

 mm/mempolicy.c:
  migrate_page_add() - reference from pte

 mm/migrate.c:
  do_move_page_to_node_array() - reference from follow_page()

 mlock.c: - various external references

 mm/vmscan.c:
  putback_lru_page() - reference from isolate_lru_page()

It seems that all isolate_lru_page() users are ready now for this
restriction.  So, let's replace redundant get_page_unless_zero() with
get_page() and add page initial reference count check with VM_BUG_ON()

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.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>

mem-hwpoison: fix page refcount around isolate_lru_page()

Drop first page reference only after calling isolate_lru_page() to keep
page stable reference while isolating.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.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>

mem-hotplug: call isolate_lru_page with elevated refcount

isolate_lru_page() must be called only with stable reference to page.  So,
let's grab normal page reference.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.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>

mm: print vmalloc() state after allocation failures

I was tracking down a page allocation failure that ended up in vmalloc().
Since vmalloc() uses 0-order pages, if somebody asks for an insane amount
of memory, we'll still get a warning with "order:0" in it.  That's not
very useful.

During recovery, vmalloc() also nicely frees all of the memory that it got
up to the point of the failure.  That is wonderful, but it also quickly
hides any issues.  We have a much different sitation if vmalloc()
repeatedly fails 10GB in to:

vmalloc(100 * 1<<30);

versus repeatedly failing 4096 bytes in to a:

vmalloc(8192);

This patch will print out messages that look like this:

[   68.123503] vmalloc: allocation failure, allocated 6680576 of 13426688 bytes
[   68.124218] bash: page allocation failure: order:0, mode:0xd2
[   68.124811] Pid: 3770, comm: bash Not tainted 2.6.39-rc3-00082-g85f2e68-dirty #333
[   68.125579] Call Trace:
[   68.125853]  [<ffffffff810f6da6>] warn_alloc_failed+0x146/0x170
[   68.126464]  [<ffffffff8107e05c>] ? printk+0x6c/0x70
[   68.126791]  [<ffffffff8112b5d4>] ? alloc_pages_current+0x94/0xe0
[   68.127661]  [<ffffffff8111ed37>] __vmalloc_node_range+0x237/0x290
...

The 'order' variable is added for clarity when calling warn_alloc_failed()
to avoid having an unexplained '0' as an argument.

The 'tmp_mask' is because adding an open-coded '| __GFP_NOWARN' would take
us over 80 columns for the alloc_pages_node() call.  If we are going to
add a line, it might as well be one that makes the sucker easier to read.

As a side issue, I also noticed that ctl_ioctl() does vmalloc() based
solely on an unverified value passed in from userspace.  Granted, it's
under CAP_SYS_ADMIN, but it still frightens me a bit.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: break out page allocation warning code

This originally started as a simple patch to give vmalloc() some more
verbose output on failure on top of the plain page allocator messages.
Johannes suggested that it might be nicer to lead with the vmalloc() info
_before_ the page allocator messages.

But, I do think there's a lot of value in what __alloc_pages_slowpath()
does with its filtering and so forth.

This patch creates a new function which other allocators can call instead
of relying on the internal page allocator warnings.  It also gives this
function private rate-limiting which separates it from other
printk_ratelimit() users.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: convert mm->cpu_vm_cpumask into cpumask_var_t

cpumask_t is very big struct and cpu_vm_mask is placed wrong position.
It might lead to reduce cache hit ratio.

This patch has two change.
1) Move the place of cpumask into last of mm_struct. Because usually cpumask
   is accessed only front bits when the system has cpu-hotplug capability
2) Convert cpu_vm_mask into cpumask_var_t. It may help to reduce memory
   footprint if cpumask_size() will use nr_cpumask_bits properly in future.

In addition, this patch change the name of cpu_vm_mask with cpu_vm_mask_var.
It may help to detect out of tree cpu_vm_mask users.

This patch has no functional change.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: thp: optimize memcg charge in khugepaged

We don't need to hold the mmmap_sem through mem_cgroup_newpage_charge(),
the mmap_sem is only hold for keeping the vma stable and we don't need the
vma stable anymore after we return from alloc_hugepage_vma().

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.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>

mm: uninline large generic tlb.h functions

Some of these functions have grown beyond inline sanity, move them
out-of-line.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Requested-by: Andrew Morton <akpm@linux-foundation.org>
Requested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: optimize page_lock_anon_vma() fast-path

Optimize the page_lock_anon_vma() fast path to be one atomic op, instead
of two.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: convert anon_vma->lock to a mutex

Straightforward conversion of anon_vma->lock to a mutex.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use refcounts for page_lock_anon_vma()

Convert page_lock_anon_vma() over to use refcounts.  This is done to
prepare for the conversion of anon_vma from spinlock to mutex.

Sadly this inceases the cost of page_lock_anon_vma() from one to two
atomics, a follow up patch addresses this, lets keep that simple for now.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: improve page_lock_anon_vma() comment

A slightly more verbose comment to go along with the trickery in
page_lock_anon_vma().

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: revert page_lock_anon_vma() lock annotation

Its beyond ugly and gets in the way.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: Convert i_mmap_lock to a mutex

Straightforward conversion of i_mmap_lock to a mutex.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: Remove i_mmap_lock lockbreak

Hugh says:
 "The only significant loser, I think, would be page reclaim (when
  concurrent with truncation): could spin for a long time waiting for
  the i_mmap_mutex it expects would soon be dropped? "

Counter points:
 - cpu contention makes the spin stop (need_resched())
 - zap pages should be freeing pages at a higher rate than reclaim
   ever can

I think the simplification of the truncate code is definitely worth it.

Effectively reverts: 2aa15890f3c ("mm: prevent concurrent
unmap_mapping_range() on the same inode") and takes out the code that
caused its problem.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lockdep, mutex: provide mutex_lock_nest_lock

In order to convert i_mmap_lock to a mutex we need a mutex equivalent to
spin_lock_nest_lock(), thus provide the mutex_lock_nest_lock() annotation.

As with spin_lock_nest_lock(), mutex_lock_nest_lock() allows annotation of
the locking pattern where an outer lock serializes the acquisition order
of nested locks.  That is, if every time you lock multiple locks A, say A1
and A2 you first acquire N, the order of acquiring A1 and A2 is
irrelevant.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: extended batches for generic mmu_gather

Instead of using a single batch (the small on-stack, or an allocated
page), try and extend the batch every time it runs out and only flush once
either the extend fails or we're done.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Requested-by: Nick Piggin <npiggin@kernel.dk>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, powerpc: move the RCU page-table freeing into generic code

In case other architectures require RCU freed page-tables to implement
gup_fast() and software filled hashes and similar things, provide the
means to do so by moving the logic into generic code.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Requested-by: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: now that all old mmu_gather code is gone, remove the storage

Fold all the mmu_gather rework patches into one for submission

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: mmu_gather rework

Fix up the um mmu_gather code to conform to the new API.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ia64: mmu_gather rework

Fix up the ia64 mmu_gather code to conform to the new API.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sh: mmu_gather rework

Fix up the sh mmu_gather code to conform to the new API.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm: mmu_gather rework

Fix up the arm mmu_gather code to conform to the new API.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390: mmu_gather rework

Adapt the stand-alone s390 mmu_gather implementation to the new
preemptible mmu_gather interface.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sparc: mmu_gather rework

Rework the sparc mmu_gather usage to conform to the new world order :-)

Sparc mmu_gather does two things:
 - tracks vaddrs to unhash
 - tracks pages to free

Split these two things like powerpc has done and keep the vaddrs
in per-cpu data structures and flush them on context switch.

The remaining bits can then use the generic mmu_gather.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: mmu_gather rework

Fix up powerpc to the new mmu_gather stuff.

PPC has an extra batching queue to RCU free the actual pagetable
allocations, use the ARCH extentions for that for now.

For the ppc64_tlb_batch, which tracks the vaddrs to unhash from the
hardware hash-table, keep using per-cpu arrays but flush on context switch
and use a TLF bit to track the lazy_mmu state.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: mmu_gather rework

Rework the existing mmu_gather infrastructure.

The direct purpose of these patches was to allow preemptible mmu_gather,
but even without that I think these patches provide an improvement to the
status quo.

The first 9 patches rework the mmu_gather infrastructure.  For review
purpose I've split them into generic and per-arch patches with the last of
those a generic cleanup.

The next patch provides generic RCU page-table freeing, and the followup
is a patch converting s390 to use this.  I've also got 4 patches from
DaveM lined up (not included in this series) that uses this to implement
gup_fast() for sparc64.

Then there is one patch that extends the generic mmu_gather batching.

After that follow the mm preemptibility patches, these make part of the mm
a lot more preemptible.  It converts i_mmap_lock and anon_vma->lock to
mutexes which together with the mmu_gather rework makes mmu_gather
preemptible as well.

Making i_mmap_lock a mutex also enables a clean-up of the truncate code.

This also allows for preemptible mmu_notifiers, something that XPMEM I
think wants.

Furthermore, it removes the new and universially detested unmap_mutex.

This patch:

Remove the first obstacle towards a fully preemptible mmu_gather.

The current scheme assumes mmu_gather is always done with preemption
disabled and uses per-cpu storage for the page batches.  Change this to
try and allocate a page for batching and in case of failure, use a small
on-stack array to make some progress.

Preemptible mmu_gather is desired in general and usable once i_mmap_lock
becomes a mutex.  Doing it before the mutex conversion saves us from
having to rework the code by moving the mmu_gather bits inside the
pte_lock.

Also avoid flushing the tlb batches from under the pte lock, this is
useful even without the i_mmap_lock conversion as it significantly reduces
pte lock hold times.

[akpm@linux-foundation.org: fix comment tpyo]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: make expand_downwards() symmetrical with expand_upwards()

Currently we have expand_upwards exported while expand_downwards is
accessible only via expand_stack or expand_stack_downwards.

check_stack_guard_page is a nice example of the asymmetry.  It uses
expand_stack for VM_GROWSDOWN while expand_upwards is called for
VM_GROWSUP case.

Let's clean this up by exporting both functions and make those names
consistent.  Let's use expand_{upwards,downwards} because expanding
doesn't always involve stack manipulation (an example is
ia64_do_page_fault which uses expand_upwards for registers backing store
expansion).  expand_downwards has to be defined for both
CONFIG_STACK_GROWS{UP,DOWN} because get_arg_page calls the downwards
version in the early process initialization phase for growsup
configuration.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmalloc: remove guard page from between vmap blocks

The vmap allocator is used to, among other things, allocate per-cpu vmap
blocks, where each vmap block is naturally aligned to its own size.
Obviously, leaving a guard page after each vmap area forbids packing vmap
blocks efficiently and can make the kernel run out of possible vmap blocks
long before overall vmap space is exhausted.

The new interface to map a user-supplied page array into linear vmalloc
space (vm_map_ram) insists on allocating from a vmap block (instead of
falling back to a custom area) when the area size is below a certain
threshold.  With heavy users of this interface (e.g.  XFS) and limited
vmalloc space on 32-bit, vmap block exhaustion is a real problem.

Remove the guard page from the core vmap allocator.  vmalloc and the old
vmap interface enforce a guard page on their own at a higher level.

Note that without this patch, we had accidental guard pages after those
vm_map_ram areas that happened to be at the end of a vmap block, but not
between every area.  This patch removes this accidental guard page only.

If we want guard pages after every vm_map_ram area, this should be done
separately.  And just like with vmalloc and the old interface on a
different level, not in the core allocator.

Mel pointed out: "If necessary, the guard page could be reintroduced as a
debugging-only option (CONFIG_DEBUG_PAGEALLOC?).  Otherwise it seems
reasonable."

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/gfp.h: convert BUG_ON() into VM_BUG_ON()

VM_BUG_ON() if effectively a BUG_ON() undef #ifdef CONFIG_DEBUG_VM.  That
is exactly what we have here now, and two different folks have suggested
doing it this way.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/gfp.h: work around apparent sparse confusion

Running sparse on page_alloc.c today, it errors out:
        include/linux/gfp.h:254:17: error: bad constant expression
        include/linux/gfp.h:254:17: error: cannot size expression

which is a line in gfp_zone():

        BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);

That's really unfortunate, because it ends up hiding all of the other
legitimate sparse messages like this:
        mm/page_alloc.c:5315:59: warning: incorrect type in argument 1 (different base types)
        mm/page_alloc.c:5315:59:    expected unsigned long [unsigned] [usertype] size
        mm/page_alloc.c:5315:59:    got restricted gfp_t [usertype] <noident>
...

Having sparse be able to catch these very oopsable bugs is a lot more
important than keeping a BUILD_BUG_ON().  Kill the BUILD_BUG_ON().

Compiles on x86_64 with and without CONFIG_DEBUG_VM=y.  defconfig boots
fine for me.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

oom: replace PF_OOM_ORIGIN with toggling oom_score_adj

There's a kernel-wide shortage of per-process flags, so it's always
helpful to trim one when possible without incurring a significant penalty.
 It's even more important when you're planning on adding a per- process
flag yourself, which I plan to do shortly for transparent hugepages.

PF_OOM_ORIGIN is used by ksm and swapoff to prefer current since it has a
tendency to allocate large amounts of memory and should be preferred for
killing over other tasks.  We'd rather immediately kill the task making
the errant syscall rather than penalizing an innocent task.

This patch removes PF_OOM_ORIGIN since its behavior is equivalent to
setting the process's oom_score_adj to OOM_SCORE_ADJ_MAX.

The process's old oom_score_adj is stored and then set to
OOM_SCORE_ADJ_MAX during the time it used to have PF_OOM_ORIGIN.  The old
value is then reinstated when the process should no longer be considered a
high priority for oom killing.

Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: 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>

mm/compaction: reverse the change that forbade sync migraton with __GFP_NO_KSWAPD

It's uncertain this has been beneficial, so it's safer to undo it.  All
other compaction users would still go in synchronous mode if a first
attempt at async compaction failed.  Hopefully we don't need to force
special behavior for THP (which is the only __GFP_NO_KSWAPD user so far
and it's the easier to exercise and to be noticeable).  This also make
__GFP_NO_KSWAPD return to its original strict semantics specific to bypass
kswapd, as THP allocations have khugepaged for the async THP
allocations/compactions.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Alex Villacis Lasso <avillaci@fiec.espol.edu.ec>
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>

mm, mem-hotplug: update pcp->stat_threshold when memory hotplug occur

Currently, cpu hotplug updates pcp->stat_threshold, but memory hotplug
doesn't.  There is no reason for this.

[akpm@linux-foundation.org: fix CONFIG_SMP=n build]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, mem-hotplug: recalculate lowmem_reserve when memory hotplug occurs

Currently, memory hotplug calls setup_per_zone_wmarks() and
calculate_zone_inactive_ratio(), but doesn't call
setup_per_zone_lowmem_reserve().

It means the number of reserved pages aren't updated even if memory hot
plug occur.  This patch fixes it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, mem-hotplug: fix section mismatch. setup_per_zone_inactive_ratio() should be __meminit.

Commit bce7394a3e ("page-allocator: reset wmark_min and inactive ratio of
zone when hotplug happens") introduced invalid section references.  Now,
setup_per_zone_inactive_ratio() is marked __init and then it can't be
referenced from memory hotplug code.

This patch marks it as __meminit and also marks caller as __ref.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-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>

x86,mm: make pagefault killable

When an oom killing occurs, almost all processes are getting stuck at the
following two points.

1) __alloc_pages_nodemask
2) __lock_page_or_retry

1) is not very problematic because TIF_MEMDIE leads to an allocation
failure and getting out from page allocator.

2) is more problematic.  In an OOM situation, zones typically don't have
page cache at all and memory starvation might lead to greatly reduced IO
performance.  When a fork bomb occurs, TIF_MEMDIE tasks don't die quickly,
meaning that a fork bomb may create new process quickly rather than the
oom-killer killing it.  Then, the system may become livelocked.

This patch makes the pagefault interruptible by SIGKILL.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
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>

mm: introduce wait_on_page_locked_killable()

commit 2687a356 ("Add lock_page_killable") introduced killable
lock_page().  Similarly this patch introdues killable
wait_on_page_locked().

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
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>

mm: per-node vmstat: show proper vmstats

commit 2ac390370a ("writeback: add
/sys/devices/system/node/<node>/vmstat") added vmstat entry.  But
strangely it only show nr_written and nr_dirtied.

        # cat /sys/devices/system/node/node20/vmstat
        nr_written 0
        nr_dirtied 0

Of course, It's not adequate.  With this patch, the vmstat show all vm
stastics as /proc/vmstat.

        # cat /sys/devices/system/node/node0/vmstat
nr_free_pages 899224
nr_inactive_anon 201
nr_active_anon 17380
nr_inactive_file 31572
nr_active_file 28277
nr_unevictable 0
nr_mlock 0
nr_anon_pages 17321
nr_mapped 8640
nr_file_pages 60107
nr_dirty 33
nr_writeback 0
nr_slab_reclaimable 6850
nr_slab_unreclaimable 7604
nr_page_table_pages 3105
nr_kernel_stack 175
nr_unstable 0
nr_bounce 0
nr_vmscan_write 0
nr_writeback_temp 0
nr_isolated_anon 0
nr_isolated_file 0
nr_shmem 260
nr_dirtied 1050
nr_written 938
numa_hit 962872
numa_miss 0
numa_foreign 0
numa_interleave 8617
numa_local 962872
numa_other 0
nr_anon_transparent_hugepages 0

[akpm@linux-foundation.org: no externs in .c files]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michael Rubin <mrubin@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: nommu: fix a compile warning in do_mmap_pgoff()

Because 'ret' is declared as int, not unsigned long, no need to cast the
error contants into unsigned long.  If you compile this code on a 64-bit
machine somehow, you'll see following warning:

    CC      mm/nommu.o
  mm/nommu.c: In function `do_mmap_pgoff':
  mm/nommu.c:1411: warning: overflow in implicit constant conversion

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: nommu: fix a potential memory leak in do_mmap_private()

If f_op->read() fails and sysctl_nr_trim_pages > 1, there could be a
memory leak between @region->vm_end and @region->vm_top.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: nommu: check the vma list when unmapping file-mapped vma

Now we have the sorted vma list, use it in do_munmap() to check that we
have an exact match.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: nommu: find vma using the sorted vma list

Now we have the sorted vma list, use it in the find_vma[_exact]() rather
than doing linear search on the rb-tree.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>