vsprintf: fix %ps on non symbols when using kallsyms

Using %ps in a printk format will sometimes fail silently and print the
empty string if the address passed in does not match a symbol that
kallsyms knows about.  But using %pS will fall back to printing the full
address if kallsyms can't find the symbol.  Make %ps act the same as %pS
by falling back to printing the address.

While we're here also make %ps print the module that a symbol comes from
so that it matches what %pS already does.  Take this simple function for
example (in a module):

static void test_printk(void)
{
int test;
pr_info("with pS: %pS\n", &test);
pr_info("with ps: %ps\n", &test);
}

Before this patch:

 with pS: 0xdff7df44
 with ps:

After this patch:

 with pS: 0xdff7df44
 with ps: 0xdff7df44

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: add LM3533 LED driver

Add sub-driver for the LEDs on National Semiconductor / TI LM3533 lighting
power chips.

The chip provides 256 brightness levels, hardware accelerated blinking as
well as ambient-light-sensor and pwm input control.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Rob Landley <rob@landley.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/leds/leds-pca955x.c: fix race condition while setting brightness on several LEDs

When issuing the following command:

  for I in 0 1 2 3 4 5 6 7; do
    echo 0 > /sys/class/leds/pca955x\:${I}/brightness;
  done

It is possible that all the pca955x_read_ls calls are done sequentially
before any pca955x_write_ls call is done.  This updates the LS only to
the last LED update in its set.

Fix this by using a global lock for the pca995x device during
pca955x_led_work.  Also used a struct for shared data betreen all LEDs.

[akpm@linux-foundation.org: revert unintentional rename of pca955x_ledsel()]
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: add new transient trigger for one shot timer activation

The leds timer trigger does not currently have an interface to activate a
one shot timer.  The current support allows for setting two timers, one
for specifying how long a state to be on, and the second for how long the
state to be off.  The delay_on value specifies the time period an LED
should stay in on state, followed by a delay_off value that specifies how
long the LED should stay in off state.  The on and off cycle repeats until
the trigger gets deactivated.  There is no provision for one time
activation to implement features that require an on or off state to be
held just once and then stay in the original state forever.

Without one shot timer interface, user space can still use timer trigger
to set a timer to hold a state, however when user space application
crashes or goes away without deactivating the timer, the hardware will be
left in that state permanently.

As a specific example of this use-case, let's look at vibrate feature on
phones.  Vibrate function on phones is implemented using PWM pins on SoC
or PMIC.  There is a need to activate one shot timer to control the
vibrate feature, to prevent user space crashes leaving the phone in
vibrate mode permanently causing the battery to drain.

This trigger exports three properties, activate, state, and duration When
transient trigger is activated these properties are set to default values.

- duration allows setting timer value in msecs. The initial value is 0.
- activate allows activating and deactivating the timer specified by
  duration as needed. The initial and default value is 0.  This will allow
  duration to be set after trigger activation.
- state allows user to specify a transient state to be held for the specified
  duration.

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: NeilBrown <neilb@suse.de>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: heartbeat: stop on shutdown

A halted kernel should not show a heartbeat.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Cc: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: driver for DA9052/53 PMIC v2

LED Driver for Dialog Semiconductor DA9052/53 PMICs.

[akpm@linux-foundation.org: make led_reg static]
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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: tosa_lcd: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: tosa_bl: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: tdo24m: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: s6e63m0: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: InKi Dae <inki.dae@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: ltv350qv: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: lms283gf05: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: ld9040: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Donghwa Lee <dh09.lee@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: l4f00242t03: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Alberto Panizzo <alberto@amarulasolutions.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: ili9320: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: corgi_lcd: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: ams369fg06: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: adp8870: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: adp8860: use devm_ functions

The devm_ functions allocate memory that is released when a driver
detaches.  This patch uses devm_kzalloc of these functions.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: initialize struct backlight_properties properly

In all these files, the .power field was never correctly initialized.

Signed-off-by: Corentin Chary <corentin.chary@gmail.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/l4f00242t03.c: use pr_fmt

This driver uses pr_debug(), so provide it with the appropriate prefixing.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Alberto Panizzo <alberto@amarulasolutions.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: progear: use pr_err() instead of printk()

Use pr_err() instead of printk() to allow dynamic debugging.  The pr_fmt
prefix for pr_ macros is used.  Also fix checkpatch warnings as below:

WARNING: printk() should include KERN_ facility level

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Marcin Juszkiewicz <openembedded@haerwu.biz>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: omap1: use pr_info() instead of printk()

Use pr_info() instead of printk() to allow dynamic debugging.  The pr_fmt
prefix for pr_ macros is used.  Also fix checkpatch warning as below:

WARNING: Prefer pr_info(... to printk(KERN_INFO, ...

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Andrzej Zaborowski <balrogg@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: jornada720: use pr_err()/pr_info() instead of printk()

Use pr_err()/pr_info() instead of printk() to allow dynamic debugging.
The pr_fmt prefix for pr_ macros is used.  Also fix checkpatch warnings as
below:

WARNING: Prefer pr_err(... to printk(KERN_ERR, ...
WARNING: Prefer pr_info(... to printk(KERN_INFO, ...

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: generic_bl: use pr_info() instead of printk()

Use pr_info() instead of printk() to allow dynamic debugging.  The pr_fmt
prefix for pr_ macros is used.  Also fix checkpatch warnings as below:

WARNING: printk() should include KERN_ facility level

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: cr_bllcd: use pr_err()/pr_info() instead of printk()

Use pr_err()/pr_info() instead of printk() to allow dynamic debugging.
The pr_fmt prefix for pr_ macros is used.  Also fix checkpatch warnings as
below:

WARNING: printk() should include KERN_ facility level
WARNING: Prefer pr_err(... to printk(KERN_ERR, ...

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: apple_bl: use pr_debug()/pr_err() instead of printk()

Use pr_debug()/pr_err() instead of printk() to allow dynamic debugging.
The pr_fmt prefix for pr_ macros is used.  Also fix checkpatch warnings as
below:

WARNING: Prefer pr_debug(... to printk(KERN_DEBUG, ...
WARNING: Prefer pr_err(... to printk(KERN_ERR, ...

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: use pr_warn() and pr_debug() instead of printk()

Use pr_warn() and pr_debug() instead of printk to allow dynamic debugging.
The pr_fmt prefix for pr_ macros is used.  Also fix checkpatch warnings
as below:

WARNING: Prefer pr_warn(... to printk(KERN_WARNING, ...

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/adp5520_bl.c: use kstrtoul()

The usage of strict_strtoul() is not preferred. Thus, kstrtoul
should be used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/adp8870_bl.c: use kstrtoul()

The usage of strict_strtoul() is not preferred. Thus, kstrtoul
should be used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/adp8860_bl.c: use kstrtoul()

The usage of strict_strtoul() is not preferred.  Thus, kstrtoul should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: add LM3533 backlight driver

Add sub-driver for the backlights on National Semiconductor / TI LM3533
lighting power chips.

The chip provides 256 brightness levels and ambient-light-sensor and pwm
input control.

[akpm@linux-foundation.org: fix warning]
[akpm@linux-foundation.org: fix the type of `mode']
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Rob Landley <rob@landley.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/apple_bl.c: include header for exported symbol prototypes

Include the header to pickup the exported symbol prototype.

Quiets the sparse warning:

  warning: symbol 'apple_bl_register' was not declared. Should it be static?
  warning: symbol 'apple_bl_unregister' was not declared. Should it be static?

[akpm@linux-foundation.org: fix resulting build error]
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: decrement static keys at real destroy time

We call the destroy function when a cgroup starts to be removed, such as
by a rmdir event.

However, because of our reference counters, some objects are still
inflight.  Right now, we are decrementing the static_keys at destroy()
time, meaning that if we get rid of the last static_key reference, some
objects will still have charges, but the code to properly uncharge them
won't be run.

This becomes a problem specially if it is ever enabled again, because now
new charges will be added to the staled charges making keeping it pretty
much impossible.

We just need to be careful with the static branch activation: since there
is no particular preferred order of their activation, we need to make sure
that we only start using it after all call sites are active.  This is
achieved by having a per-memcg flag that is only updated after
static_key_slow_inc() returns.  At this time, we are sure all sites are
active.

This is made per-memcg, not global, for a reason: it also has the effect
of making socket accounting more consistent.  The first memcg to be
limited will trigger static_key() activation, therefore, accounting.  But
all the others will then be accounted no matter what.  After this patch,
only limited memcgs will have its sockets accounted.

[akpm@linux-foundation.org: move enum sock_flag_bits into sock.h,
                            document enum sock_flag_bits,
                            convert memcg_proto_active() and memcg_proto_activated() to test_bit(),
                            redo tcp_update_limit() comment to 80 cols]
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: always free struct memcg through schedule_work()

Right now we free struct memcg with kfree right after a rcu grace period,
but defer it if we need to use vfree() to get rid of that memory area.  We
do that by need, because we need vfree to be called in a process context.

This patch unifies this behavior, by ensuring that even kfree will happen
in a separate thread.  The goal is to have a stable place to call the
upcoming jump label destruction function outside the realm of the
complicated and quite far-reaching cgroup lock (that can't be held when
holding either the cpu_hotplug.lock or jump_label_mutex)

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Glauber Costa <glommer@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcg: apply add/del_page to lruvec

Take lruvec further: pass it instead of zone to add_page_to_lru_list() and
del_page_from_lru_list(); and pagevec_lru_move_fn() pass lruvec down to
its target functions.

This cleanup eliminates a swathe of cruft in memcontrol.c, including
mem_cgroup_lru_add_list(), mem_cgroup_lru_del_list() and
mem_cgroup_lru_move_lists() - which never actually touched the lists.

In their place, mem_cgroup_page_lruvec() to decide the lruvec, previously
a side-effect of add, and mem_cgroup_update_lru_size() to maintain the
lru_size stats.

Whilst these are simplifications in their own right, the goal is to bring
the evaluation of lruvec next to the spin_locking of the lrus, in
preparation for a future patch.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: trivial cleanups in vmscan.c

Utter trivia in mm/vmscan.c, mostly just reducing the linecount slightly;
most exciting change being get_scan_count() calling vmscan_swappiness()
once instead of twice.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcg: get_lru_size not get_lruvec_size

Konstantin just introduced mem_cgroup_get_lruvec_size() and
get_lruvec_size(), I'm about to add mem_cgroup_update_lru_size(): but
we're dealing with the same thing, lru_size[lru].  We ought to agree on
the naming, and I do think lru_size is the more correct: so rename his
ones to get_lru_size().

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcg: print statistics from live counters

Directly print statistics and event counters instead of going through an
intermediate accumulation stage into a separate array, which used to
require defining statistic items in more than one place.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcg: group swapped-out statistics counter logically

The counter of currently swapped out pages in a memcg (hierarchy) is
sitting amidst ever-increasing event counters.  Move this item to the
other counters that reflect current state rather than history.

This technically breaks the kernel ABI, but hopefully nobody relies on the
order of items in memory.stat.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcg: keep ratelimit counter separate from event counters

All events except the ratelimit counter are statistics exported to
userspace.  Keep this internal value out of the event count array.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcg: print statistics directly to seq_file

Being able to use seq_printf() allows being smarter about statistics
name strings, which are currently listed twice, with the only difference
being a "total_" prefix on the hierarchical version.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcg: convert numa stat to read_seq_string interface

Instead of using the raw seq_file file interface, switch over to the
read_seq_string cftype callback and let cgroup core code set up the
seq_file.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcg: remove obsolete statistics array boundary enum item

MEM_CGROUP_STAT_DATA is a leftover from when item counters were living in
the same array as ever-increasing event counters.  It's no longer needed,
use MEM_CGROUP_STAT_NSTATS to iterate over the stat array.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rescounter: remove __must_check from res_counter_charge_nofail()

Since we will succeed with the allocation no matter what, there isn't a
need to use __must_check with it.  It can very well be optional.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ying Han <yinghan@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: don't uncharge in mem_cgroup_move_account()

Now, all callers pass 'false' for 'bool uncharge' so remove this argument.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ying Han <yinghan@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: move charges to root cgroup if use_hierarchy=0

Presently, at removal of cgroup, ->pre_destroy() is called and moves
charges to the parent cgroup.  A major reason for returning -EBUSY from
->pre_destroy() is that the 'moving' hits the parent's resource
limitation.  It happens only when use_hierarchy=0.

Considering use_hierarchy=0, all cgroups should be flat.  So, no one
cannot justify moving charges to parent...parent and children are in flat
configuration, not hierarchical.

This patch modifes the code to move charges to the root cgroup at
rmdir/force_empty if use_hierarchy==0.  This will much simplify rmdir()
and reduce error in ->pre_destroy.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ying Han <yinghan@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memcg: use res_counter_uncharge_until() in move_parent()

By using res_counter_uncharge_until(), we can avoid race and unnecessary
charging.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ying Han <yinghan@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rescounters: add res_counter_uncharge_until()

When killing a res_counter which is a child of other counter, we need to
do

res_counter_uncharge(child, xxx)
res_counter_charge(parent, xxx)

This is not atomic and wastes CPU.  This patch adds
res_counter_uncharge_until().  This function's uncharge propagates to
ancestors until specified res_counter.

res_counter_uncharge_until(child, parent, xxx)

Now the operation is atomic and efficient.

Signed-off-by: Frederic Weisbecker <fweisbec@redhat.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ying Han <yinghan@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan: kill struct mem_cgroup_zone

Kill struct mem_cgroup_zone and rename shrink_mem_cgroup_zone() to
shrink_lruvec(), it always shrinks one lruvec which it takes as an
argument.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: push lruvec pointer into should_continue_reclaim()

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: push lruvec pointer into get_scan_count()

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: push lruvec pointer into shrink_list()

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: push lruvec pointer into inactive_list_is_low()

Switch mem_cgroup_inactive_anon_is_low() to lruvec pointers,
mem_cgroup_get_lruvec_size() is more effective than
mem_cgroup_zone_nr_lru_pages()

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: replace zone_nr_lru_pages() with get_lruvec_size()

If memory cgroup is enabled we always use lruvecs which are embedded into
struct mem_cgroup_per_zone, so we can reach lru_size counters via
container_of().

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: push lruvec pointer into putback_inactive_pages()

As zone_reclaim_stat is now located in the lruvec, we can reach it
directly.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: remove update_isolated_counts()

update_isolated_counts() is no longer required, because lumpy-reclaim was
removed.  Insanity is over, now there is only one kind of inactive page.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: push zone pointer into shrink_page_list()

It doesn't need a pointer to the cgroup - pointer to the zone is enough.
This patch also kills the "mz" argument of page_check_references() - it is
unused after "mm: memcg: count pte references from every member of the
reclaimed hierarch"

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: push lruvec pointer into isolate_lru_pages()

Move the mem_cgroup_zone_lruvec() call from isolate_lru_pages() into
shrink_[in]active_list().  Further patches push it to shrink_zone() step
by step.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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: add link from struct lruvec to struct zone

This is the first stage of struct mem_cgroup_zone removal.  Further
patches replace struct mem_cgroup_zone with a pointer to struct lruvec.

If CONFIG_CGROUP_MEM_RES_CTLR=n lruvec_zone() is just container_of().

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/vmscan: store "priority" in struct scan_control

In memory reclaim some function have too many arguments - "priority" is
one of them.  It can be stored in struct scan_control - we construct them
on the same level.  Instead of an open coded loop we set the initial
sc.priority, and do_try_to_free_pages() decreases it down to zero.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-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/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.

[akpm@linux-foundation.org: fix build (patch skew)]
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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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.

[akpm@linux-foundation.org: fix kerneldoc, per Minchan]
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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memblock: fix memory leak on extending regions

The overall memblock has been organized into the memory regions and
reserved regions.  Initially, the memory regions and reserved regions are
stored in the predetermined arrays of "struct memblock _region".  It's
possible for the arrays to be enlarged when we have newly added regions,
but no free space left there.  The policy here is to create double-sized
array either by slab allocator or memblock allocator.  Unfortunately, we
didn't free the old array, which might be allocated through slab allocator
before.  That would cause memory leak.

The patch introduces 2 variables to trace where (slab or memblock) the
memory and reserved regions come from.  The memory for the memory or
reserved regions will be deallocated by kfree() if that was allocated by
slab allocator.  Thus to fix the memory leak issue.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memblock: cleanup on duplicate VA/PA conversion

The overall memblock has been organized into the memory regions and
reserved regions.  Initially, the memory regions and reserved regions are
stored in the predetermined arrays of "struct memblock _region".  It's
possible for the arrays to be enlarged when we have newly added regions
for them, but no enough space there.  Under the situation, We will created
double-sized array to meet the requirement.  However, the original
implementation converted the VA (Virtual Address) of the newly allocated
array of regions to PA (Physical Address), then translate back when we
allocates the new array from slab.  That's actually unnecessary.

The patch removes the duplicate VA/PA conversion.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix slab->page flags corruption

Transparent huge pages can change page->flags (PG_compound_lock) without
taking Slab lock.  Since THP can not break slab pages we can safely access
compound page without taking compound lock.

Specifically this patch fixes a race between compound_unlock() and slab
functions which perform page-flags updates.  This can occur when
get_page()/put_page() is called on a page from slab.

[akpm@linux-foundation.org: tweak comment text, fix comment layout, fix label indenting]
Reported-by: Amey Bhide <abhide@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix faulty initialization in vmalloc_init()

The transfer of ->flags causes some of the static mapping virtual
addresses to be prematurely freed (before the mapping is removed) because
VM_LAZY_FREE gets "set" if tmp->flags has VM_IOREMAP set.  This might
cause subsequent vmalloc/ioremap calls to fail because it might allocate
one of the freed virtual address ranges that aren't unmapped.

va->flags has different types of flags from tmp->flags.  If a region with
VM_IOREMAP set is registered with vm_area_add_early(), it will be removed
by __purge_vmap_area_lazy().

Fix vmalloc_init() to correctly initialize vmap_area for the given
vm_struct.

Also initialise va->vm.  If it is not set, find_vm_area() for the early
vm regions will always fail.

Signed-off-by: KyongHo Cho <pullip.cho@samsung.com>
Cc: "Olav Haugan" <ohaugan@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: pmd_read_atomic: fix 32bit PAE pmd walk vs pmd_populate SMP race condition

When holding the mmap_sem for reading, pmd_offset_map_lock should only
run on a pmd_t that has been read atomically from the pmdp pointer,
otherwise we may read only half of it leading to this crash.

PID: 11679  TASK: f06e8000  CPU: 3   COMMAND: "do_race_2_panic"
 #0 [f06a9dd8] crash_kexec at c049b5ec
 #1 [f06a9e2c] oops_end at c083d1c2
 #2 [f06a9e40] no_context at c0433ded
 #3 [f06a9e64] bad_area_nosemaphore at c043401a
 #4 [f06a9e6c] __do_page_fault at c0434493
 #5 [f06a9eec] do_page_fault at c083eb45
 #6 [f06a9f04] error_code (via page_fault) at c083c5d5
    EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP:
    00000000
    DS:  007b     ESI: 9e201000 ES:  007b     EDI: 01fb4700 GS:  00e0
    CS:  0060     EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246
 #7 [f06a9f38] _spin_lock at c083bc14
 #8 [f06a9f44] sys_mincore at c0507b7d
 #9 [f06a9fb0] system_call at c083becd
                         start           len
    EAX: ffffffda  EBX: 9e200000  ECX: 00001000  EDX: 6228537f
    DS:  007b      ESI: 00000000  ES:  007b      EDI: 003d0f00
    SS:  007b      ESP: 62285354  EBP: 62285388  GS:  0033
    CS:  0073      EIP: 00291416  ERR: 000000da  EFLAGS: 00000286

This should be a longstanding bug affecting x86 32bit PAE without THP.
Only archs with 64bit large pmd_t and 32bit unsigned long should be
affected.

With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad()
would partly hide the bug when the pmd transition from none to stable,
by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is
enabled a new set of problem arises by the fact could then transition
freely in any of the none, pmd_trans_huge or pmd_trans_stable states.
So making the barrier in pmd_none_or_trans_huge_or_clear_bad()
unconditional isn't good idea and it would be a flakey solution.

This should be fully fixed by introducing a pmd_read_atomic that reads
the pmd in order with THP disabled, or by reading the pmd atomically
with cmpxchg8b with THP enabled.

Luckily this new race condition only triggers in the places that must
already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix
is localized there but this bug is not related to THP.

NOTE: this can trigger on x86 32bit systems with PAE enabled with more
than 4G of ram, otherwise the high part of the pmd will never risk to be
truncated because it would be zero at all times, in turn so hiding the
SMP race.

This bug was discovered and fully debugged by Ulrich, quote:

----
[..]
pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and
eax.

    496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t
    *pmd)
    497 {
    498         /* depend on compiler for an atomic pmd read */
    499         pmd_t pmdval = *pmd;

                                // edi = pmd pointer
0xc0507a74 <sys_mincore+548>:   mov    0x8(%esp),%edi
...
                                // edx = PTE page table high address
0xc0507a84 <sys_mincore+564>:   mov    0x4(%edi),%edx
...
                                // eax = PTE page table low address
0xc0507a8e <sys_mincore+574>:   mov    (%edi),%eax

[..]

Please note that the PMD is not read atomically. These are two "mov"
instructions where the high order bits of the PMD entry are fetched
first. Hence, the above machine code is prone to the following race.

-  The PMD entry {high|low} is 0x0000000000000000.
   The "mov" at 0xc0507a84 loads 0x00000000 into edx.

-  A page fault (on another CPU) sneaks in between the two "mov"
   instructions and instantiates the PMD.

-  The PMD entry {high|low} is now 0x00000003fda38067.
   The "mov" at 0xc0507a8e loads 0xfda38067 into eax.
----

Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, oom: normalize oom scores to oom_score_adj scale only for userspace

The oom_score_adj scale ranges from -1000 to 1000 and represents the
proportion of memory available to the process at allocation time.  This
means an oom_score_adj value of 300, for example, will bias a process as
though it was using an extra 30.0% of available memory and a value of
-350 will discount 35.0% of available memory from its usage.

The oom killer badness heuristic also uses this scale to report the oom
score for each eligible process in determining the "best" process to
kill.  Thus, it can only differentiate each process's memory usage by
0.1% of system RAM.

On large systems, this can end up being a large amount of memory: 256MB
on 256GB systems, for example.

This can be fixed by having the badness heuristic to use the actual
memory usage in scoring threads and then normalizing it to the
oom_score_adj scale for userspace.  This results in better comparison
between eligible threads for kill and no change from the userspace
perspective.

Suggested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: avoid swapping out with swappiness==0

Sometimes we'd like to avoid swapping out anonymous memory.  In
particular, avoid swapping out pages of important process or process
groups while there is a reasonable amount of pagecache on RAM so that we
can satisfy our customers' requirements.

OTOH, we can control how aggressive the kernel will swap memory pages with
/proc/sys/vm/swappiness for global and
/sys/fs/cgroup/memory/memory.swappiness for each memcg.

But with current reclaim implementation, the kernel may swap out even if
we set swappiness=0 and there is pagecache in RAM.

This patch changes the behavior with swappiness==0.  If we set
swappiness==0, the kernel does not swap out completely (for global reclaim
until the amount of free pages and filebacked pages in a zone has been
reduced to something very very small (nr_free + nr_filebacked < high
watermark)).

Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>