lib/bitmap.c: fix documentation for scnprintf() functions

The code comments for bscnl_emit() and bitmap_scnlistprintf() are
describing snprintf() return semantics, but these functions use
scnprintf() return semantics.  Fix that, and document the
bitmap_scnprintf() return value as well.

Cc: Ryota Ozaki <ozaki.ryota@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/string_helpers.c: make arrays static

Moving these arrays into static storage shrinks the kernel a bit:

   text    data     bss     dec     hex filename
    723     112      64     899     383 lib/string_helpers.o
    516     272      64     852     354 lib/string_helpers.o

Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/test-kstrtox.c: mark const init data with __initconst instead of __initdata

As long as there is no other non-const variable marked __initdata in the
same compilation unit it doesn't hurt. If there were one however
compilation would fail with

error: $variablename causes a section type conflict

because a section containing const variables is marked read only and so
cannot contain non-const variables.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

list_debug: WARN for adding something already in the list

We were bitten by this at one point and added an additional sanity test
for DEBUG_LIST.  You can't validly add a list_head to a list where either
prev or next is the same as the thing you're adding.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds-heartbeat-stop-on-shutdown-checkpatch-fixes

ERROR: space prohibited after that '!' (ctx:WxW)
#45: FILE: drivers/leds/ledtrig-heartbeat.c:121:
+ if( ! rc )
      ^

ERROR: space prohibited after that open parenthesis '('
#45: FILE: drivers/leds/ledtrig-heartbeat.c:121:
+ if( ! rc )

ERROR: space prohibited before that close parenthesis ')'
#45: FILE: drivers/leds/ledtrig-heartbeat.c:121:
+ if( ! rc )

ERROR: space required before the open parenthesis '('
#45: FILE: drivers/leds/ledtrig-heartbeat.c:121:
+ if( ! rc )

total: 4 errors, 0 warnings, 36 lines checked

./patches/leds-heartbeat-stop-on-shutdown.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Alexander Holler <holler@ahsoftware.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: heartbeat: stop on shutdown

A halted kernel should not show a heartbeat.

Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Cc: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/leds/leds-lm3530.c: simplify als configuration on initialization

For better code readability, ALS code is moved to new a function -
lm3530_als_configure()

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/led-lm3530.h: comment correction about the range of brightness

max brightness is 127, so the range of brt_val should be from 0 to 127

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: change ledtrig-timer to use activated flag

Change existing timer trigger to use the new ->activated flag to set
activate successful status in activate routine and check it in deactivate
routine to do cleanup.

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: change existing triggers to use activated flag

Change existing triggers backlight, gpio, and heartbeat to use the new
->activated flag to set activate successful status in their activate
routines and check it in their deactivate routines to do cleanup.

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: add new field to led_classdev struct to save activation state

Add a new field to led_classdev to save activattion state after activate
routine is successful.  This saved state is used in deactivate routine to
do cleanup such as removing device files, and free memory allocated during
activation.  Currently trigger_data not being null is used for this
purpose.

Existing triggers will need changes to use this new field.

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: Use kcalloc instead of kzalloc to allocate array

The advantage of kcalloc is that will prevent integer overflows which
could result from the multiplication of number of elements and size and it
is also a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: simple_strtoul() cleanup

led-class.c and ledtrig-timer.c still use simple_strtoul().  Change them
to use kstrtoul() instead of obsolete simple_strtoul().

Also fix the existing int ret declaration to be ssize_t to match the
return type for _store functions in ledtrig-timer.c.

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: lm3556: Don't call kfree for the memory allocated by devm_kzalloc

The devm_* functions eliminate the need for manual resource releasing
and simplify error handling. Resources allocated by devm_* are freed
automatically on driver detach.

Thus adding kfree calls here will introduce double free bug.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Geon Si Jeong <gshark.jeong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds-add-led-driver-for-lm3556-chip-checkpatch-fixes

WARNING: please write a paragraph that describes the config symbol fully
#35: FILE: drivers/leds/Kconfig:405:
+config LEDS_LM3556

ERROR: "foo * bar" should be "foo *bar"
#204: FILE: drivers/leds/leds-lm3556.c:142:
+static int lm3556_read_reg(struct i2c_client *client, u8 reg, u8 * val)

total: 1 errors, 1 warnings, 736 lines checked

./patches/leds-add-led-driver-for-lm3556-chip.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Geon Si Jeong <gshark.jeong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: add LED driver for lm3556 chip

A simple driver for the Texas Instruments LM3556 chip.

The LM3556 is a 4 MHz fixed-frequency synchronous boost converter plus
1.5A constant current driver for a high-current white LED.  Datasheet:
www.national.com/ds/LM/LM3556.pdf

Tested on OMAP4430

Signed-off-by: Geon Si Jeong <gshark.jeong@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Daniel Jeong <daniel.jeong@ti.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Greg KH <greg@kroah.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds-led-module-for-da9052-53-pmic-v2-fix

Cc: Ashish Jangam <ashish.jangam@kpitcummins.com>
Cc: David Dajun Chen <dchen@diasemi.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

leds: driver for DA9052/53 PMIC v2

LED Driver for Dialog Semiconductor DA9052/53 PMICs.

Signed-off-by: David Dajun Chen <dchen@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/leds/leds-lp5521.c: fix lp5521_read() error handling

Gcc 4.6.2 complains that:
drivers/leds/leds-lp5521.c: In function `lp5521_load_program':
drivers/leds/leds-lp5521.c:214:21: warning: `mode' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c: In function `lp5521_probe':
drivers/leds/leds-lp5521.c:788:5: warning: `buf' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c:740:6: warning: `ret' may be used uninitialized in this function [-Wuninitialized]

These are real problems if lp5521_read() returns an error.  When that
happens we should handle it, instead of ignoring it or doing a bitwise OR
with all the other error codes and continuing.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Milo <Milo.Kim@ti.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fbdev: add events for early fb event support

Add FB_EARLY_EVENT_BLANK and FB_R_EARLY_EVENT_BLANK event mode supports.
first, fb_notifier_call_chain() is called with FB_EARLY_EVENT_BLANK and
fb_blank() of specific fb driver is called and then
fb_notifier_call_chain() is called with FB_EVENT_BLANK again at
fb_blank().  and if fb_blank() was failed then fb_nitifier_call_chain()
would be called with FB_R_EARLY_EVENT_BLANK to revert the previous
effects.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lcd: add callbacks for early fb event blank support

This patchset adds early fb blank feature that a callback of lcd panel
driver is called prior to specific fb driver's one.  In the case of
MIPI-DSI based video mode LCD Panel, for lcd power off, the power off
commands should be transferred to lcd panel with display and mipi-dsi
controller enabled because the commands is set to lcd panel at vsync porch
period.  and in opposite case, the callback of fb driver should be called
prior to lcd panel driver's one because of same issue.  Also if fb_blank
mode is changed to FB_BLANK_POWERDOWN then display controller would be
off(clock disable) but lcd panel would be still on.  at this time, you
could see some issue like sparkling on lcd panel because video clock to be
delivered to ldi module of lcd panel was disabled.  this issue could
occurs for all lcd panels.

The callback order is as the following:

at fb_blank function of fbmem.c
-> fb_notifier_call_chain(FB_EARLY_EVENT_BLANK)
       -> lcd panel driver's early_set_power()
-> info->fbops->fb_blank()
       -> spcefic fb driver's fb_blank()
-> fb_notifier_call_chain(FB_EVENT_BLANK)
       -> lcd panel driver's set_power()
   -> fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK) if
info->fops->fb_blank() was failed.

fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK) would be called to revert
the effects of previous FB_EARLY_EVENT_BLANK call.  and note that if
early_set_power() of lcd_ops is NULL then early fb blank callback would be
ignored.

This patch:

Add early_set_power and r_early_set_power callbacks.  early_set_power
callback is called prior to fb_blank() of fbmem.c and r_early_set_power
callback is called if fb_blank() was failed to revert the effects of the
early_set_power call of lcd panel driver.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

blacklight: remove redundant spi driver bus initialization

In ancient times it was necessary to manually initialize the bus field of
an spi_driver to spi_bus_type.  These days this is done in
spi_driver_register() so we can drop the manual assignment.

The patch was generated using the following coccinelle semantic patch:
// <smpl>
@@
identifier _driver;
@@
struct spi_driver _driver = {
.driver = {
- .bus = &spi_bus_type,
},
};
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

MAINTAINERS: remove Alessandro

I'm definitely not up to date on the subject matter any more
and haven't been able to comment on the messages on the topic.

Signed-off-by: Alessandro Rubini <rubini@ipvvis.unipv.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hamradio/scc: orphan driver in MAINTAINERS

The email address doesn't exist anymore and the website yields a 404.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

vsprintf-further-optimize-decimal-conversion-checkpatch-fixes

WARNING: line over 80 characters
#112: FILE: lib/vsprintf.c:136:
+  * (x * 0x00cd) >> 11     x <       1029 shorter code than * 0x67 (on i386)

ERROR: trailing statements should be on next line
#192: FILE: lib/vsprintf.c:178:
+ if (q == 0) return buf;

ERROR: trailing statements should be on next line
#195: FILE: lib/vsprintf.c:181:
+ if (r == 0) return buf;

ERROR: trailing statements should be on next line
#198: FILE: lib/vsprintf.c:184:
+ if (q == 0) return buf;

ERROR: trailing statements should be on next line
#201: FILE: lib/vsprintf.c:187:
+ if (r == 0) return buf;

ERROR: trailing statements should be on next line
#204: FILE: lib/vsprintf.c:190:
+ if (q == 0) return buf;

ERROR: trailing statements should be on next line
#207: FILE: lib/vsprintf.c:193:
+ if (r == 0) return buf;

ERROR: trailing statements should be on next line
#210: FILE: lib/vsprintf.c:196:
+ if (q == 0) return buf;

ERROR: space prohibited after that '&' (ctx:WxW)
#290: FILE: lib/vsprintf.c:267:
+ d2  = (h      ) & 0xffff;
                  ^

ERROR: space prohibited before that close parenthesis ')'
#290: FILE: lib/vsprintf.c:267:
+ d2  = (h      ) & 0xffff;

total: 9 errors, 1 warnings, 310 lines checked

./patches/vsprintf-further-optimize-decimal-conversion.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

vsprintf-further-optimize-decimal-conversion-v2

Here is a new version. I also plugged a hole in num_to_str() -
it was assuming it's safe to call put_dec() for num=0.
(We never tripped over it before because the single caller
of num_to_str() takes care of that case).

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Douglas W Jones <jones@cs.uiowa.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

vsprintf: further optimize decimal conversion

Previous code was using optimizations which were developed to work well
even on narrow-word CPUs (by today's standards).  But Linux runs only on
32-bit and wider CPUs.  We can use that.

First: using 32x32->64 multiply and trivial 32-bit shift, we can correctly
divide by 10 much larger numbers, and thus we can print groups of 9 digits
instead of groups of 5 digits.

Next: there are two algorithms to print larger numbers.  One is generic:
divide by 1000000000 and repeatedly print groups of (up to) 9 digits.
It's conceptually simple, but requires an (unsigned long long) /
1000000000 division.

Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
manipulates them cleverly and generates groups of 4 decimal digits.  It so
happens that it does NOT require long long division.

If long is > 32 bits, division of 64-bit values is relatively easy, and we
will use the first algorithm.  If long long is > 64 bits (strange
architecture with VERY large long long), second algorithm can't be used,
and we again use the first one.

Else (if long is 32 bits and long long is 64 bits) we use second one.

And third: there is a simple optimization which takes fast path not only
for zero as was done before, but for all one-digit numbers.

In all tested cases new code is faster than old one, in many cases by 30%,
in few cases by more than 50% (for example, on x86-32, conversion of
12345678).  Code growth is ~0 in 32-bit case and ~130 bytes in 64-bit
case.

This patch is based upon an original from Michal Nazarewicz.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Douglas W Jones <jones@cs.uiowa.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

vsprintf-correctly-handle-width-when-flag-used-in-%p-format-checkpatch-fixes

ERROR: "(foo*)" should be "(foo *)"
#20: FILE: lib/vsprintf.c:869:
+ int default_width = 2 * sizeof(void*) + (spec.flags & SPECIAL ? 2 : 0);

total: 1 errors, 0 warnings, 32 lines checked

./patches/vsprintf-correctly-handle-width-when-flag-used-in-%p-format.patch has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

vsprintf: correctly handle width when '#' flag used in %#p format.

needs decent changelog!

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

sethostname/setdomainname: notify userspace when there is a change in uts_kern_table

sethostname() and setdomainname() notify userspace on failure (without
modifying uts_kern_table).  Change things so that we only notify userspace
on success, when uts_kern_table was actually modified.

Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: WANG Cong <amwang@redhat.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

introduce SIZE_MAX

ULONG_MAX is often used to check for integer overflow when calculating
allocation size.  While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.

This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Alex Elder <elder@dreamhost.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parisc: use set_current_blocked() and block_sigmask()

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block is
pending in the shared queue.

Also, use the new helper function introduced in commit 5e6292c0f28f
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate code
across architectures.  In the past some architectures got this code wrong,
so using this helper function should stop that from happening again.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

CodingStyle: add kmalloc_array() to memory allocators

Add the new kmalloc_array() to the list of general-purpose memory
allocators in chapter 14.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Acked-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

checkpatch: check for spin_is_locked()

spin_is_locked() is usually misued. In checkpatch.pl:

- warn when it is used at all

- error out when it is asserted on free, because that's usually broken
  (e.g.  doesn't work on on uni processor builds).  Recommend
  lockdep_assert_held() instead.

[joe@perches.com: some improvements]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/spinlock.h: add a kerneldoc comment to spin_is_locked() that discourages its use

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

spinlockstxt-add-a-discussion-on-why-spin_is_locked-is-bad-fix

- s/hold/held in various places

- reindent for 80 cols

- a few grammatical tweaks

Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

spinlocks.txt: add a discussion on why spin_is_locked() is bad

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/net/ethernet/smsc/smsc911x.h: use lockdep_assert_held() instead of home grown buggy construct

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/net/irda/sir_dev.c: remove spin_is_locked()

It's hard to imagine how this spin_is_locked() debugging check is not
totally racy.  Remove it.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Samuel Ortiz <samuel@sortiz.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

futex: use lockdep_assert_held() for lock checking

Use lockdep_assert_held() for lock checking instead of a strange homegrown
variant.  This removes the return for this case, but that is unlikely to
be useful anyway.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/huge_memory.c: use lockdep_assert_held()

Use lockdep_assert_held() to check for locks instead of an opencoded
variant.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

XFS: fix lock ASSERT on UP

ASSERT(!spin_is_locked()) doesn't work on UP builds.  Replace with a
standard lockdep_assert_held()

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/scsi/aha152x.c: remove broken usage of spin_is_locked()

Remove racy usage of spin_is_locked. The author seems to have been
unclear on the concept of locking.

This is debug code normally not enabled, but I caught it on a tree sweep.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

sgi-xp: use lockdep_assert_held()

!spin_is_locked() is always true on a UP build, so it cannot be used for
assertions.  Replace with lockdep_assert_held().

I realize UP builds are not very likely for this driver, but it's still
better to fix it.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

um/kernel/trap.c: port OOM changes to handle_page_fault()

Commit d065bd810b6deb6 ("mm: retry page fault when blocking on disk
transfer") and commit 37b23e0525 ("x86,mm: make pagefault killable")

The above commits introduced changes into the x86 pagefault handler
for making the page fault handler retryable as well as killable.

These changes reduce the mmap_sem hold time, which is crucial
during OOM killer invocation.

Port these changes to um.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

frv: use set_current_blocked() and block_sigmask()

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block is
pending in the shared queue.

Also, use the new helper function introduced in commit 5e6292c0f28f
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate code
across architectures.  In the past some architectures got this code wrong,
so using this helper function should stop that from happening again.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

security/keys/keyctl.c: suppress memory allocation failure warning

This allocation may be large.  The code is probing to see if it will
succeed and if not, it falls back to vmalloc().  We should suppress any
page-allocation failure messages when the fallback happens.

Reported-by: Dave Jones <davej@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcg: use vm_swappiness from target memory cgroup

Use vm_swappiness from memory cgroup which is triggered this memory
reclaim.  This is more reasonable and allows to kill one argument.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: revise the position of threshold index while unregistering event

Index current_threshold should point to threshold just below or equal to
usage.  See below: http://www.spinics.net/lists/cgroups/msg00844.html

Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: make threshold index in the right position

Index current_threshold may point to threshold that just equal to usage
after last call of __mem_cgroup_threshold.  But after registering a new
event, it will change (pointing to threshold just below usage).  So make
it consistent here.

For example:
now:
threshold array:  3  [5]  7  9   (usage = 6, [index] = 5)

next turn (after calling __mem_cgroup_threshold):
threshold array:  3   5  [7]  9   (usage = 7, [index] = 7)

after registering a new event (threshold = 10):
threshold array:  3  [5]  7  9  10 (usage = 7, [index] = 5)

Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: remove redundant parentheses

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: mark stat field of mem_cgroup struct as __percpu

It fixes a lot of sparse warnings.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: remove unused variable

mm/memcontrol.c: In function `mc_handle_file_pte':
mm/memcontrol.c:5206:16: warning: variable `inode' set but not used [-Wunused-but-set-variable]

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: mark more functions/variables as static

Based on sparse output.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcg: kill mem_cgroup_lru_del()

This patch kills mem_cgroup_lru_del(), we can use
mem_cgroup_lru_del_list() instead.  On 0-order isolation we already have
right lru list id.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: remove lru type checks from __isolate_lru_page()

After patch "mm: forbid lumpy-reclaim in shrink_active_list()" we can
completely remove anon/file and active/inactive lru type filters from
__isolate_lru_page(), because isolation for 0-order reclaim always
isolates pages from right lru list.  And pages-isolation for lumpy
shrink_inactive_list() or memory-compaction anyway allowed to isolate
pages from all evictable lru lists.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: mark mm-inline functions as __always_inline

GCC sometimes ignores "inline" directives even for small and simple functions.
This supposed to be fixed in gcc 4.7, but it was released only yesterday.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm-push-lru-index-into-shrink_active_list-fix

fix kerneldoc, per Minchan

Cc: Glauber Costa <glommer@parallels.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: push lru index into shrink_[in]active_list()

Let's toss lru index through call stack to isolate_lru_pages(), this is
better than its reconstructing from individual bits.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcg: move reclaim_stat into lruvec

With mem_cgroup_disabled() now explicit, it becomes clear that the
zone_reclaim_stat structure actually belongs in lruvec, per-zone when
memcg is disabled but per-memcg per-zone when it's enabled.

We can delete mem_cgroup_get_reclaim_stat(), and change
update_page_reclaim_stat() to update just the one set of stats, the one
which get_scan_count() will actually use.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcg: scanning_global_lru means mem_cgroup_disabled

Although one has to admire the skill with which it has been concealed,
scanning_global_lru(mz) is actually just an interesting way to test
mem_cgroup_disabled().  Too many developer hours have been wasted on
confusing it with global_reclaim(): just use mem_cgroup_disabled().

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg swap: use mem_cgroup_uncharge_swap()

That stuff __mem_cgroup_commit_charge_swapin() does with a swap entry, it
has a name and even a declaration: just use mem_cgroup_uncharge_swap().

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg swap: mem_cgroup_move_swap_account never needs fixup

The need_fixup arg to mem_cgroup_move_swap_account() is always false,
so just remove it.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: fix/change behavior of shared anon at moving task

This patch changes memcg's behavior at task_move().

At task_move(), the kernel scans a task's page table and move the changes
for mapped pages from source cgroup to target cgroup.  There has been a
bug at handling shared anonymous pages for a long time.

Before patch:
  - The spec says 'shared anonymous pages are not moved.'
  - The implementation was 'shared anonymoys pages may be moved'.
    If page_mapcount <=2, shared anonymous pages's charge were moved.

After patch:
  - The spec says 'all anonymous pages are moved'.
  - The implementation is 'all anonymous pages are moved'.

Considering usage of memcg, this will not affect user's experience.
'shared anonymous' pages only exists between a tree of processes which
don't do exec().  Moving one of process without exec() seems not sane.
For example, libcgroup will not be affected by this change.  (Anyway, no
one noticed the implementation for a long time...)

Below is a discussion log:

 - current spec/implementation are complex
 - Now, shared file caches are moved
 - It adds unclear check as page_mapcount(). To do correct check,
   we should check swap users, etc.
 - No one notice this implementation behavior. So, no one get benefit
   from the design.
 - In general, once task is moved to a cgroup for running, it will not
   be moved....
 - Finally, we have control knob as memory.move_charge_at_immigrate.

Here is a patch to allow moving shared pages, completely. This makes
memcg simpler and fix current broken code.

Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/vmstat.c: remov debug fs entries on failure of file creation and made extfrag_debug_root dentry local

Removed debug fs files and directory on failure.  Since no one using
"extfrag_debug_root" dentry outside of function extfrag_debug_init made it
local to the function.

Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/fork: fix overflow in vma length when copying mmap on clone

The vma length in dup_mmap is calculated and stored in a unsigned int,
which is insufficient and hence overflows for very large maps (beyond
16TB). The following program demonstrates this:

#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>

#define GIG 1024 * 1024 * 1024L
#define EXTENT 16393

int main(void)
{
        int i, r;
        void *m;
        char buf[1024];

        for (i = 0; i < EXTENT; i++) {
                m = mmap(NULL, (size_t) 1 * 1024 * 1024 * 1024L,
                         PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);

                if (m == (void *)-1)
                        printf("MMAP Failed: %d\n", m);
                else
                        printf("%d : MMAP returned %p\n", i, m);

                r = fork();

                if (r == 0) {
                        printf("%d: successed\n", i);
                        return 0;
                } else if (r < 0)
                        printf("FORK Failed: %d\n", r);
                else if (r > 0)
                        wait(NULL);
        }
        return 0;
}

Increase the storage size of the result to unsigned long, which is
sufficient for storing the difference between addresses.

Signed-off-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm-mmapc-find_vma-remove-unnecessary-ifmm-check-fix

add remove-me comment

Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Rajman Mekaco <rajman.mekaco@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/mmap.c: find_vma(): remove unnecessary if(mm) check

The if(mm) check is not required in find_vma, as the kernel code calls
find_vma only when it is absolutely sure that the mm_struct arg to it is
non-NULL.

Remove the if(mm) check and adding the a WARN_ONCE(!mm) for now.  This
will serve the purpose of mandating that the execution
context(user-mode/kernel-mode) be known before find_vma is called.  Also
fixed 2 checkpatch.pl errors in the declaration of the rb_node and vma_tmp
local variables.

I was browsing through the internet and read a discussion at
https://lkml.org/lkml/2012/3/27/342 which discusses removal of the
validation check within find_vma.  Since no-one responded, I decided to
send this patch with Andrew's suggestions.

Signed-off-by: Rajman Mekaco <rajman.mekaco@gmail.com>
Cc: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: use kcalloc() instead of kzalloc() to allocate array

The advantage of kcalloc is, that will prevent integer overflows which
could result from the multiplication of number of elements and size and it
is also a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: fix off-by-one bug in print_nodes_state()

/sys/devices/system/node/{online,possible} outputs a garbage byte because
print_nodes_state() returns content size + 1.  To fix the bug, the patch
changes the use of cpuset_sprintf_cpulist to follow the use at other
places, which is clearer and safer.

This bug was introduced since v2.6.24 (bde631a51876f23e9).

Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: add memory controller documentation for hugetlb management

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb-migrate-memcg-info-from-oldpage-to-new-page-during-migration-fix

remove strange double-spaces

Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb: migrate memcg info from oldpage to new page during migration

With HugeTLB pages, memcg is uncharged in compound page destructor.  Since
we are holding a hugepage reference, we can be sure that old page won't
get uncharged till the last put_page().  On successful migrate, we can
move the memcg information to new page's page_cgroup and mark the old
page's page_cgroup unused.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg-move-hugetlb-resource-count-to-parent-cgroup-on-memcg-removal-fix-fix

Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg-move-hugetlb-resource-count-to-parent-cgroup-on-memcg-removal-fix

fix CONFIG_MEM_RES_CTLR_HUGETLB=n warnings

include/linux/memcontrol.h:504: warning: 'struct cgroup' declared inside parameter list
include/linux/memcontrol.h:504: warning: its scope is only this definition or declaration, which is probably not what you want
include/linux/memcontrol.h:509: warning: 'struct cgroup' declared inside parameter list

Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: move HugeTLB resource count to parent cgroup on memcg removal

Add support for memcg removal with HugeTLB resource usage.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlbfs: add a list for tracking in-use HugeTLB pages

hugepage_activelist will be used to track currently used HugeTLB pages.
We need to find the in-use HugeTLB pages to support memcg removal.  On
memcg removal we update the page's memory cgroup to point to parent
cgroup.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlbfs-add-memcg-control-files-for-hugetlbfs-use-scnprintf-instead-of-sprintf-fix

s/scnprintf/snprintf/

Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: use scnprintf instead of sprintf

Make sure we don't overflow.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlbfs: add memcg control files for hugetlbfs

Add the control files for hugetlbfs in memcg.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: track resource index in cftype private

This patch adds a new charge type _MEMHUGETLB for tracking hugetlb
resources.  We also use cftype to encode the hugetlb resource index.  This
helps in using same memcg callbacks for hugetlb control files.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb: add charge/uncharge calls for HugeTLB alloc/free

This adds necessary charge/uncharge calls in the HugeTLB code.  We do
memcg charge in page alloc and uncharge in compound page destructor.  We
also need to ignore HugeTLB pages in __mem_cgroup_uncharge_common because
that get called from delete_from_page_cache

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

memcg: add HugeTLB extension

This patch implements a memcg extension that allows us to control HugeTLB
allocations via memory controller.  The extension allows to limit the
HugeTLB usage per control group and enforces the controller limit during
page fault.  Since HugeTLB doesn't support page reclaim, enforcing the
limit at page fault time implies that, the application will get SIGBUS
signal if it tries to access HugeTLB pages beyond its limit.  This
requires the application to know beforehand how much HugeTLB pages it
would require for its use.

The charge/uncharge calls will be added to HugeTLB code in later patch.
Support for memcg removal will be added in later patches.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb: simplify migrate_huge_page()

Since we migrate only one hugepage don't use linked list for passing the
page around.  Directly pass page that need to be migrated as argument.
This also remove the usage page->lru in migrate path.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb: avoid taking i_mmap_mutex in unmap_single_vma() for hugetlb

i_mmap_mutex lock was added in unmap_single_vma by 502717f4e ("hugetlb:
fix linked list corruption in unmap_hugepage_range()") but we don't use
page->lru in unmap_hugepage_range any more.  Also the lock was taken
higher up in the stack in some code path.  That would result in deadlock.

unmap_mapping_range (i_mmap_mutex)
 -> unmap_mapping_range_tree
    -> unmap_mapping_range_vma
       -> zap_page_range_single
         -> unmap_single_vma
      -> unmap_hugepage_range (i_mmap_mutex)

For shared pagetable support for huge pages, since pagetable pages are ref
counted we don't need any lock during huge_pmd_unshare.  We do take
i_mmap_mutex in huge_pmd_share while walking the vma_prio_tree in mapping.
(39dde65c9940c97f ("shared page table for hugetlb page")).

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb-use-mmu_gather-instead-of-a-temporary-linked-list-for-accumulating-pages-fix-fix

In file included from fs/proc/meminfo.c:2:
include/linux/hugetlb.h:126: warning: 'struct mmu_gather' declared inside parameter list
include/linux/hugetlb.h:126: warning: its scope is only this definition or declaration, which is probably not what you want

what a mess :(

Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb-use-mmu_gather-instead-of-a-temporary-linked-list-for-accumulating-pages-fix

fix CONFIG_HUGETLB_PAGE=n build

mm/memory.c: In function 'unmap_single_vma':
mm/memory.c:1334: error: implicit declaration of function '__unmap_hugepage_range'

Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages

Use an mmu_gather instead of a temporary linked list for accumulating
pages when we unmap a hugepage range.  This also allows us to get rid of
i_mmap_mutex unmap_hugepage_range in the following patch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlbfs: add an inline helper for finding hstate index

Add an inline helper and use it in the code.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlbfs: don't use ERR_PTR with VM_FAULT* values

The current use of VM_FAULT_* codes with ERR_PTR requires us to ensure
VM_FAULT_* values will not exceed MAX_ERRNO value.  Decouple the
VM_FAULT_* values from MAX_ERRNO.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

hugetlb: rename max_hstate to hugetlb_max_hstate

This patchset implements a memory controller extension to control HugeTLB
allocations.  The extension allows to limit the HugeTLB usage per control
group and enforces the controller limit during page fault.  Since HugeTLB
doesn't support page reclaim, enforcing the limit at page fault time
implies that, the application will get SIGBUS signal if it tries to access
HugeTLB pages beyond its limit.  This requires the application to know
beforehand how much HugeTLB memory it would require for its use.

The goal is to control how many HugeTLB pages a group of tasks can
allocate.  It can be looked at as an extension of the existing quota
interface which limits the number of HugeTLB pages per hugetlbfs
superblock.  An HPC job scheduler requires jobs to specify their resource
requirements in the job file.  Once their requirements can be met, job
schedulers (such as SLURM) will schedule the job.  We need to make sure
that the jobs won't consume more resources than requested.  If they do we
should either error out or kill the application.

This patch:

Rename max_hstate to hugetlb_max_hstate.  We will be using this from other
subsystems like memcg in later patches.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: vmscan: remove reclaim_mode_t

There is little motiviation for reclaim_mode_t once RECLAIM_MODE_[A]SYNC
and lumpy reclaim have been removed.  This patch gets rid of
reclaim_mode_t as well and improves the documentation about what
reclaim/compaction is and when it is triggered.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: vmscan: do not stall on writeback during memory compaction

This patch stops reclaim/compaction entering sync reclaim as this was only
intended for lumpy reclaim and an oversight.  Page migration has its own
logic for stalling on writeback pages if necessary and memory compaction
is already using it.

Waiting on page writeback is bad for a number of reasons but the primary
one is that waiting on writeback to a slow device like USB can take a
considerable length of time.  Page reclaim instead uses
wait_iff_congested() to throttle if too many dirty pages are being
scanned.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: vmscan: remove lumpy reclaim

This series removes lumpy reclaim and some stalling logic that was
unintentionally being used by memory compaction.  The end result is that
stalling on dirty pages during page reclaim now depends on
wait_iff_congested().

Four kernels were compared

3.3.0     vanilla
3.4.0-rc2 vanilla
3.4.0-rc2 lumpyremove-v2 is patch one from this series
3.4.0-rc2 nosync-v2r3 is the full series

Removing lumpy reclaim saves almost 900 bytes of text whereas the full
series removes 1200 bytes.

   text    data     bss     dec     hex filename
6740375 1927944 2260992 10929311  a6c49f vmlinux-3.4.0-rc2-vanilla
6739479 1927944 2260992 10928415  a6c11f vmlinux-3.4.0-rc2-lumpyremove-v2
6739159 1927944 2260992 10928095  a6bfdf vmlinux-3.4.0-rc2-nosync-v2

There are behaviour changes in the series and so tests were run with
monitoring of ftrace events.  This disrupts results so the performance
results are distorted but the new behaviour should be clearer.

fs-mark running in a threaded configuration showed little of interest as
it did not push reclaim aggressively

FS-Mark Multi Threaded
                        3.3.0-vanilla       rc2-vanilla       lumpyremove-v2r3       nosync-v2r3
Files/s  min           3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)
Files/s  mean          3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)
Files/s  stddev        0.00 ( 0.00%)        0.00 ( 0.00%)        0.00 ( 0.00%)        0.00 ( 0.00%)
Files/s  max           3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)        3.20 ( 0.00%)
Overhead min      508667.00 ( 0.00%)   521350.00 (-2.49%)   544292.00 (-7.00%)   547168.00 (-7.57%)
Overhead mean     551185.00 ( 0.00%)   652690.73 (-18.42%)   991208.40 (-79.83%)   570130.53 (-3.44%)
Overhead stddev    18200.69 ( 0.00%)   331958.29 (-1723.88%)  1579579.43 (-8578.68%)     9576.81 (47.38%)
Overhead max      576775.00 ( 0.00%)  1846634.00 (-220.17%)  6901055.00 (-1096.49%)   585675.00 (-1.54%)
MMTests Statistics: duration
Sys Time Running Test (seconds)             309.90    300.95    307.33    298.95
User+Sys Time Running Test (seconds)        319.32    309.67    315.69    307.51
Total Elapsed Time (seconds)               1187.85   1193.09   1191.98   1193.73

MMTests Statistics: vmstat
Page Ins                                       80532       82212       81420       79480
Page Outs                                  111434984   111456240   111437376   111582628
Swap Ins                                           0           0           0           0
Swap Outs                                          0           0           0           0
Direct pages scanned                           44881       27889       27453       34843
Kswapd pages scanned                        25841428    25860774    25861233    25843212
Kswapd pages reclaimed                      25841393    25860741    25861199    25843179
Direct pages reclaimed                         44881       27889       27453       34843
Kswapd efficiency                                99%         99%         99%         99%
Kswapd velocity                            21754.791   21675.460   21696.029   21649.127
Direct efficiency                               100%        100%        100%        100%
Direct velocity                               37.783      23.375      23.031      29.188
Percentage direct scans                           0%          0%          0%          0%

ftrace showed that there was no stalling on writeback or pages submitted
for IO from reclaim context.

postmark was similar and while it was more interesting, it also did not
push reclaim heavily.

POSTMARK
                                     3.3.0-vanilla       rc2-vanilla  lumpyremove-v2r3       nosync-v2r3
Transactions per second:               16.00 ( 0.00%)    20.00 (25.00%)    18.00 (12.50%)    17.00 ( 6.25%)
Data megabytes read per second:        18.80 ( 0.00%)    24.27 (29.10%)    22.26 (18.40%)    20.54 ( 9.26%)
Data megabytes written per second:     35.83 ( 0.00%)    46.25 (29.08%)    42.42 (18.39%)    39.14 ( 9.24%)
Files created alone per second:        28.00 ( 0.00%)    38.00 (35.71%)    34.00 (21.43%)    30.00 ( 7.14%)
Files create/transact per second:       8.00 ( 0.00%)    10.00 (25.00%)     9.00 (12.50%)     8.00 ( 0.00%)
Files deleted alone per second:       556.00 ( 0.00%)  1224.00 (120.14%)  3062.00 (450.72%)  6124.00 (1001.44%)
Files delete/transact per second:       8.00 ( 0.00%)    10.00 (25.00%)     9.00 (12.50%)     8.00 ( 0.00%)

MMTests Statistics: duration
Sys Time Running Test (seconds)             113.34    107.99    109.73    108.72
User+Sys Time Running Test (seconds)        145.51    139.81    143.32    143.55
Total Elapsed Time (seconds)               1159.16    899.23    980.17   1062.27

MMTests Statistics: vmstat
Page Ins                                    13710192    13729032    13727944    13760136
Page Outs                                   43071140    42987228    42733684    42931624
Swap Ins                                           0           0           0           0
Swap Outs                                          0           0           0           0
Direct pages scanned                               0           0           0           0
Kswapd pages scanned                         9941613     9937443     9939085     9929154
Kswapd pages reclaimed                       9940926     9936751     9938397     9928465
Direct pages reclaimed                             0           0           0           0
Kswapd efficiency                                99%         99%         99%         99%
Kswapd velocity                             8576.567   11051.058   10140.164    9347.109
Direct efficiency                               100%        100%        100%        100%
Direct velocity                                0.000       0.000       0.000       0.000

It looks like here that the full series regresses performance but as
ftrace showed no usage of wait_iff_congested() or sync reclaim I am
assuming it's a disruption due to monitoring.  Other data such as memory
usage, page IO, swap IO all looked similar.

Running a benchmark with a plain DD showed nothing very interesting.  The
full series stalled in wait_iff_congested() slightly less but stall times
on vanilla kernels were marginal.

Running a benchmark that hammered on file-backed mappings showed stalls
due to congestion but not in sync writebacks

MICRO
                                     3.3.0-vanilla       rc2-vanilla  lumpyremove-v2r3       nosync-v2r3
MMTests Statistics: duration
Sys Time Running Test (seconds)             308.13    294.50    298.75    299.53
User+Sys Time Running Test (seconds)        330.45    316.28    318.93    320.79
Total Elapsed Time (seconds)               1814.90   1833.88   1821.14   1832.91

MMTests Statistics: vmstat
Page Ins                                      108712      120708       97224      110344
Page Outs                                  155514576   156017404   155813676   156193256
Swap Ins                                           0           0           0           0
Swap Outs                                          0           0           0           0
Direct pages scanned                         2599253     1550480     2512822     2414760
Kswapd pages scanned                        69742364    71150694    68839041    69692533
Kswapd pages reclaimed                      34824488    34773341    34796602    34799396
Direct pages reclaimed                         53693       94750       61792       75205
Kswapd efficiency                                49%         48%         50%         49%
Kswapd velocity                            38427.662   38797.901   37799.972   38022.889
Direct efficiency                                 2%          6%          2%          3%
Direct velocity                             1432.174     845.464    1379.807    1317.446
Percentage direct scans                           3%          2%          3%          3%
Page writes by reclaim                             0           0           0           0
Page writes file                                   0           0           0           0
Page writes anon                                   0           0           0           0
Page reclaim immediate                             0           0           0        1218
Page rescued immediate                             0           0           0           0
Slabs scanned                                  15360       16384       13312       16384
Direct inode steals                                0           0           0           0
Kswapd inode steals                             4340        4327        1630        4323

FTrace Reclaim Statistics: congestion_wait
Direct number congest     waited                 0          0          0          0
Direct time   congest     waited               0ms        0ms        0ms        0ms
Direct full   congest     waited                 0          0          0          0
Direct number conditional waited               900        870        754        789
Direct time   conditional waited               0ms        0ms        0ms       20ms
Direct full   conditional waited                 0          0          0          0
KSwapd number congest     waited              2106       2308       2116       1915
KSwapd time   congest     waited          139924ms   157832ms   125652ms   132516ms
KSwapd full   congest     waited              1346       1530       1202       1278
KSwapd number conditional waited             12922      16320      10943      14670
KSwapd time   conditional waited               0ms        0ms        0ms        0ms
KSwapd full   conditional waited                 0          0          0          0

Reclaim statistics are not radically changed.  The stall times in kswapd
are massive but it is clear that it is due to calls to congestion_wait()
and that is almost certainly the call in balance_pgdat().  Otherwise
stalls due to dirty pages are non-existant.

I ran a benchmark that stressed high-order allocation.  This is very
artifical load but was used in the past to evaluate lumpy reclaim and
compaction.  Generally I look at allocation success rates and latency
figures.

STRESS-HIGHALLOC
                 3.3.0-vanilla       rc2-vanilla  lumpyremove-v2r3       nosync-v2r3
Pass 1          81.00 ( 0.00%)    28.00 (-53.00%)    24.00 (-57.00%)    28.00 (-53.00%)
Pass 2          82.00 ( 0.00%)    39.00 (-43.00%)    38.00 (-44.00%)    43.00 (-39.00%)
while Rested    88.00 ( 0.00%)    87.00 (-1.00%)    88.00 ( 0.00%)    88.00 ( 0.00%)

MMTests Statistics: duration
Sys Time Running Test (seconds)             740.93    681.42    685.14    684.87
User+Sys Time Running Test (seconds)       2922.65   3269.52   3281.35   3279.44
Total Elapsed Time (seconds)               1161.73   1152.49   1159.55   1161.44

MMTests Statistics: vmstat
Page Ins                                     4486020     2807256     2855944     2876244
Page Outs                                    7261600     7973688     7975320     7986120
Swap Ins                                       31694           0           0           0
Swap Outs                                      98179           0           0           0
Direct pages scanned                           53494       57731       34406      113015
Kswapd pages scanned                         6271173     1287481     1278174     1219095
Kswapd pages reclaimed                       2029240     1281025     1260708     1201583
Direct pages reclaimed                          1468       14564       16649       92456
Kswapd efficiency                                32%         99%         98%         98%
Kswapd velocity                             5398.133    1117.130    1102.302    1049.641
Direct efficiency                                 2%         25%         48%         81%
Direct velocity                               46.047      50.092      29.672      97.306
Percentage direct scans                           0%          4%          2%          8%
Page writes by reclaim                       1616049           0           0           0
Page writes file                             1517870           0           0           0
Page writes anon                               98179           0           0           0
Page reclaim immediate                        103778       27339        9796       17831
Page rescued immediate                             0           0           0           0
Slabs scanned                                1096704      986112      980992      998400
Direct inode steals                              223      215040      216736      247881
Kswapd inode steals                           175331       61548       68444       63066
Kswapd skipped wait                            21991           0           1           0
THP fault alloc                                    1         135         125         134
THP collapse alloc                               393         311         228         236
THP splits                                        25          13           7           8
THP fault fallback                                 0           0           0           0
THP collapse fail                                  3           5           7           7
Compaction stalls                                865        1270        1422        1518
Compaction success                               370         401         353         383
Compaction failures                              495         869        1069        1135
Compaction pages moved                        870155     3828868     4036106     4423626
Compaction move failure                        26429       23865       29742       27514

Success rates are completely hosed for 3.4-rc2 which is almost certainly
due to [fe2c2a10: vmscan: reclaim at order 0 when compaction is enabled].
I expected this would happen for kswapd and impair allocation success
rates (https://lkml.org/lkml/2012/1/25/166) but I did not anticipate this
much a difference: 80% less scanning, 37% less reclaim by kswapd

In comparison, reclaim/compaction is not aggressive and gives up easily
which is the intended behaviour.  hugetlbfs uses __GFP_REPEAT and would be
much more aggressive about reclaim/compaction than THP allocations are.
The stress test above is allocating like neither THP or hugetlbfs but is
much closer to THP.

Mainline is now impaired in terms of high order allocation under heavy
load although I do not know to what degree as I did not test with
__GFP_REPEAT.  Keep this in mind for bugs related to hugepage pool
resizing, THP allocation and high order atomic allocation failures from
network devices.

In terms of congestion throttling, I see the following for this test

FTrace Reclaim Statistics: congestion_wait
Direct number congest     waited                 3          0          0          0
Direct time   congest     waited               0ms        0ms        0ms        0ms
Direct full   congest     waited                 0          0          0          0
Direct number conditional waited               957        512       1081       1075
Direct time   conditional waited               0ms        0ms        0ms        0ms
Direct full   conditional waited                 0          0          0          0
KSwapd number congest     waited                36          4          3          5
KSwapd time   congest     waited            3148ms      400ms      300ms      500ms
KSwapd full   congest     waited                30          4          3          5
KSwapd number conditional waited             88514        197        332        542
KSwapd time   conditional waited            4980ms        0ms        0ms        0ms
KSwapd full   conditional waited                49          0          0          0

The "conditional waited" times are the most interesting as this is
directly impacted by the number of dirty pages encountered during scan.
As lumpy reclaim is no longer scanning contiguous ranges, it is finding
fewer dirty pages.  This brings wait times from about 5 seconds to 0.
kswapd itself is still calling congestion_wait() so it'll still stall but
it's a lot less.

In terms of the type of IO we were doing, I see this

FTrace Reclaim Statistics: mm_vmscan_writepage
Direct writes anon  sync                         0          0          0          0
Direct writes anon  async                        0          0          0          0
Direct writes file  sync                         0          0          0          0
Direct writes file  async                        0          0          0          0
Direct writes mixed sync                         0          0          0          0
Direct writes mixed async                        0          0          0          0
KSwapd writes anon  sync                         0          0          0          0
KSwapd writes anon  async                    91682          0          0          0
KSwapd writes file  sync                         0          0          0          0
KSwapd writes file  async                   822629          0          0          0
KSwapd writes mixed sync                         0          0          0          0
KSwapd writes mixed async                        0          0          0          0

In 3.2, kswapd was doing a bunch of async writes of pages but
reclaim/compaction was never reaching a point where it was doing sync IO.
This does not guarantee that reclaim/compaction was not calling
wait_on_page_writeback() but I would consider it unlikely.  It indicates
that merging patches 2 and 3 to stop reclaim/compaction calling
wait_on_page_writeback() should be safe.

This patch:

Lumpy reclaim had a purpose but in the mind of some, it was to kick the
system so hard it trashed.  For others the purpose was to complicate
vmscan.c.  Over time it was giving softer shoes and a nicer attitude but
memory compaction needs to step up and replace it so this patch sends
lumpy reclaim to the farm.

The tracepoint format changes for isolating LRU pages with this patch
applied.  Furthermore reclaim/compaction can no longer queue dirty pages
in pageout() if the underlying BDI is congested.  Lumpy reclaim used this
logic and reclaim/compaction was using it in error.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm: remove swap token code

The swap token code no longer fits in with the current VM model.  It does
not play well with cgroups or the better NUMA placement code in
development, since we have only one swap token globally.

It also has the potential to mess with scalability of the system, by
increasing the number of non-reclaimable pages on the active and inactive
anon LRU lists.

Last but not least, the swap token code has been broken for a year without
complaints, as reported by Konstantin Khlebnikov.  This suggests we no
longer have much use for it.

The days of sub-1G memory systems with heavy use of swap are over.  If we
ever need thrashing reducing code in the future, we will have to implement
something that does scale.

Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Bob Picco <bpicco@meloft.net>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm, thp: allow fallback when pte_alloc_one() fails for huge pmd

The transparent hugepages feature is careful to not invoke the oom killer
when a hugepage cannot be allocated.

pte_alloc_one() failing in __do_huge_pmd_anonymous_page(), however,
currently results in VM_FAULT_OOM which invokes the pagefault oom killer
to kill a memory-hogging task.

This is unnecessary since it's possible to drop the reference to the
hugepage and fallback to allocating a small page.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm, thp: remove unnecessary ret variable

The "ret" variable is unnecessary in __do_huge_pmd_anonymous_page(), so
remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/hugetlb.c: use long vars instead of int in region_count()

args f & t and fields from & to of struct file_region are defined as long.
 Use long instead of int to type the temp vars.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/mempolicy.c: use enum value MPOL_REBIND_ONCE in mpol_rebind_policy()

We have enum definition in mempolicy.h: MPOL_REBIND_ONCE.  It should
replace the magic number 0 for step comparison in function
mpol_rebind_policy.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory_failure: let the compiler add the function name

These things tend to get out of sync with time so let the compiler
automatically enter the current function name using __func__.

No functional change.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Acked-by: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>