drivers/rtc/interface.c: fix alarm rollover when day or month is out-of-range

Commit f44f7f96a20a ("RTC: Initialize kernel state from RTC") introduced a
potential infinite loop.  If an alarm time contains a wildcard month and
an invalid day (> 31), or a wildcard year and an invalid month (>= 12),
the loop searching for the next matching date will never terminate.  Treat
the invalid values as wildcards.

Fixes <http://bugs.debian.org/646429>, <http://bugs.debian.org/653331>

Reported-by: leo weppelman <leoweppelman@googlemail.com>
Reported-by: "P. van Gaans" <mailme667@yahoo.co.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-twl.c: add DT support for RTC inside twl4030/twl6030

Add the DT support for the TI rtc-twl present in the twl4030 and twl6030
devices.

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/: 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: John Stultz <john.stultz@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-jz4740.c: make jz4740_rtc_driver static

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-mc13xxx.c: make mc13xxx_rtc_idtable static

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc: convert drivers/rtc/* to use module_platform_driver()

This patch converts the drivers in drivers/rtc/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: John Stultz <john.stultz@linaro.org>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-wm831x.c: convert to devm_kzalloc()

Marginally less code and eliminate the possibility of memory leaks.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-wm831x.c: remove unused period IRQ handler

Due to changes in the RTC core the period interrupt is now unused so
delete the code managing it.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc/ab8500: add calibration attribute to AB8500 RTC

The rtc_calibration attribute allows user-space to get and set the
AB8500's RtcCalibration register.  The AB8500 will then use the value in
this register to compensate for RTC drift every 60 seconds.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mark Godfrey <mark.godfrey@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-ab8500.c: change msleep() to usleep_range()

The resolution of msleep is related to HZ, so with HZ set to 100 any
msleep of less than 10ms will become ~10ms.  This is not what we want.
Use the hrtimer-based usleep_range() and allow for some slack in the
non-critical path so we have more control of what is happening here.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Jonas Aaberg <jonas.aberg@stericsson.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc/ab8500: set can_wake flag

Set can_wake flag so wakealarm property is visible in sysfs.

Signed-off-by: Andrew Lynn <andrew.lynn@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtc/ab8500: don't disable IRQ:s when suspending

We want this driver to be able to wake up the system.

Signed-off-by: Robert Marklund <robert.marklund@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-mxc.c: make alarm work

Fix alarm IRQ handling, make the alarm one-shot.  Cleanup black magick
with a validation of already validated time data.

Add ability to wake the system with alarm.

[akpm@linux-foundation.org: fix CONFIG_PM=n build]
Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-mxc.c: fix setting time for MX1 SoC

There is no way to track year in the i.MX1 RTC: Days Counter register is
9-bit wide only.  Attempt to save date after 1970-01-01 plus 512 days
causes endless loop in mxc_rtc_set_mmss().  Fix this by resetting year to
1970.

[akpm@linux-foundation.org: use conventional comment layout]
Signed-off-by: Yauhen Kharuzhy <jekhor@gmail.com>
Cc: Daniel Mack <daniel@caiaq.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-cmos.c: fix broken NVRAM bank 2 writing

Fix writing to NVRAM bank 2 in rtc-cmos driver.  It never worked since its
introduction in 2.6.28 because of a typo.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MIPS: randomize PIE load address

... by selecting ARCH_BINFMT_ELF_RANDOMIZE_PIE

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs: binfmt_elf: create Kconfig variable for PIE randomization

Randomization of PIE load address is hard coded in binfmt_elf.c for X86
and ARM.  Create a new Kconfig variable
(CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE) for this and use it instead.  Thus
architecture specific policy is pushed out of the generic binfmt_elf.c and
into the architecture Kconfig files.

X86 and ARM Kconfigs are modified to select the new variable so there is
no change in behavior.  A follow on patch will select it for MIPS too.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

crc32: optimize inner loop

Taking a pointer reference to each row in the crc table matrix, one can
reduce the inner loop with a few insn's

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Frank Zago <fzago@systemfabricworks.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: catch all occurences of type and cast spacing errors per line

Fix up type and cast spacing checks such that all occurences on a line are
examined and reported.  For example the line below has a valid cast and a
bad type, but currently we check the cast first which is good and stop:

    u16* bar = (u16 *)baz;

We will also only report one of the errors in this example:

    u16* bar = (u16*)bad;

Move to iterating across all casts and all types, reporting any failure.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: typeof may have more complex arguments

typeof may have various more complex forms as its arguement, not just an
identifier.  For now allow us to leak to the first close perenthesis ')'.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: ensure cast type is unique in the context parser

Ensure the cast type is unique in the context parser, we do not want them
to detect as a comma ','.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix complex macros handling of square brackets

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix 'return is not a function' square bracket handling

We are incorrectly matching square brackets '[' and ']' leading to false
positives on more complex functions as below:

    return (dt3155_fbuffer[m]->ready_head -
dt3155_fbuffer[m]->ready_len +
dt3155_fbuffer[m]->nbuffers)%
(dt3155_fbuffer[m]->nbuffers);

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: complex macro should allow the empty do while loop

It is common to stub out a function as below, this is triggering a complex
macro format incorrectly.  Sort this out:

    #define cma_early_regions_reserve(reserve)   do { } while (0)

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix EXPORT_SYMBOL handling following a function

The following fragment defeats the DEVICE_ATTR style handing, check for
and ignore the close brace '}' in this context:

    int foo()
    {
    }
    DEVICE_ATTR(link_power_management_policy, S_IRUGO | S_IWUSR,
                ata_scsi_lpm_show, ata_scsi_lpm_put);
    EXPORT_SYMBOL_GPL(dev_attr_link_power_management_policy);

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: only apply kconfig help checks for options which prompt

The intent of this check is to catch the options which the user will see
and ensure they are properly described.  It is also common for internal
only options to have a brief description.  Allow this form.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: optimise statement scanner when mid-statement

In the middle of a long definition or similar, there is no possibility of
finding a smaller sub-statement.  Optimise this case by skipping statement
aquirey where there are no starts of statement (open brace '{' or
semi-colon ';').  We are likely to scan slightly more than needed still
but this is safest.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: ## is not a valid modifier

Inserting a # into the modifiers list will incorrectly add the null string
to the modifiers list, leading to an infinite loop.  As neither of these
is a valid modifier form simply ignore them.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve memset and min/max with cast checking

Improve the checking of arguments to memset and min/max tests.

Move the checking of min/max to statement blocks instead of single line.
Change $Constant to allow any case type 0x initiator and trailing ul
specifier.  Add $FuncArg type as any function argument with or without a
cast.  Print the whole statement when showing memset or min/max messages.
Improve the memset with 0 as 3rd argument error message.

There are still weaknesses in the $FuncArg and $Constant code as arbitrary
parentheses and negative signs are not generically supported.

[akpm@linux-foundation.org: fix per Andy]
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: check for common memset parameter issues against statments

Move the memset checks over to work against the statement.  Also add
checks for 0 and 1 used as lengths.  Generally these indicate badly
ordered parameters.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: correctly track the end of preprocessor commands in context

When looking for a statement we currently run on through preprocessor
commands.  This means that a header file with just definitions is parsed
over and over again combining all of the lines from the current line to
the end of file leading to severe performance issues.

Fix up context accumulation to track preprocessor commands and stop when
reaching the end of them.  At the same time vastly simplify the #define
handling.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: prefer __printf over __attribute__((format(printf,...)))

Add a warn for not using __printf.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: update signature "might be better as" warning

email header lines can look like signature tags.  It's valid to have
multiple email recipients on a single line but not valid to have multiple
signatures on a single line.

Validate signatures only when not in the email headers.

Clear the $in_commit_log flag when the patch filename appears.

Add '-' to the valid chars in a message header for headers
like "Message-Id:" and "In-Reply-To:".

Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

btree: export btree_get_prev() so modules can use btree_for_each

The btree_for_each API is implemented with macros that internally call
btree_get_prev(), so if btree_get_prev() isn't exported then modules fail
to link if they try to use one of the btree_for_each macros.  Since the
rest of the btree API is exported, we should keep things orthogonal and
make this work too.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Steve Hodgson <steve@purestorage.com>
Acked-by: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: convert wm8350 driver to devm_kzalloc()

Saves a small amount of code and systematically eliminates leaks.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.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>

leds: convert wm831x status driver to devm_kzalloc()

Saves a small amount of code and systematically eliminates leaks.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.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/leds/leds-mc13783.c: fix off-by-one for checking num_leds

The LED id begins from 0.  Thus the maximum number of leds should be
MC13783_LED_MAX + 1.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Philippe Retornaz <philippe.retornaz@epfl.ch>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: add driver for TCA6507 LED controller

TI's TCA6507 is the LED driver in the GTA04 Openmoko motherboard.  The
driver provides full support for brightness levels and hardware blinking.

This driver can drive each of 7 outputs as an LED or a GPIO output,
and provides hardware-assist blinking.

[akpm@linux-foundation.org: fix __mod_i2c_device_table alias]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/leds/leds-netxbig.c: use gpio_request_one()

Use gpio_request_one() instead of multiple gpiolib calls.  This also
simplifies error handling a bit.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Simon Guinot <sguinot@lacie.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/leds/leds-bd2802.c: use gpio_request_one()

Use gpio_request_one() instead of multiple gpiolib calls.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Kim Kyuwon <q1.kim@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>

drivers/leds/leds-lp5523.c: remove unneeded forward declaration

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Samu Onkalo <samu.p.onkalo@nokia.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>

leds: convert leds-dac124s085 to module_spi_driver

Factor out some boilerplate code for spi driver registration into
module_spi_driver.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Haojian Zhuang <hzhuang1@marvell.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Michael Hennerich <hennerich@blackfin.uclinux.org>
Cc: Mike Rapoport <mike@compulab.co.il>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: convert led i2c drivers to module_i2c_driver

Factor out some boilerplate code for i2c driver registration
into module_i2c_driver.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Haojian Zhuang <hzhuang1@marvell.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Michael Hennerich <hennerich@blackfin.uclinux.org>
Cc: Mike Rapoport <mike@compulab.co.il>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: convert led platform drivers to module_platform_driver

Factor out some boilerplate code for platform driver registration into
module_platform_driver.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Haojian Zhuang <hzhuang1@marvell.com> [led-88pm860x.c]
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Michael Hennerich <hennerich@blackfin.uclinux.org>
Cc: Mike Rapoport <mike@compulab.co.il>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: convert pwm_bl to dev_pm_ops

Should be no functional changes, mainly a reorganisation to support future
work.

[akpm@linux-foundation.org: fix CONFIG_PM=n build]
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: convert platform_lcd to devm_kzalloc()

Saves some error handling code and eliminates a class of leaks.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: use kstrtoul()

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

This patch also fixes checkpatch error as follows:
ERROR: space required after that ',' (ctx:VxV)

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>

drivers/video/backlight/ep93xx_bl.c: remove duplicated header include

module.h is included twice.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@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.c: regulator control in the driver

This patch supports regulator power control in the driver.  Current ld9040
driver was controlled power on/off sequence by callback function in the
board file.  But, by doing this, there's no need to register lcd power
on/off callback function in the board file.

Signed-off-by: Donghwa Lee <dh09.lee@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: convert drivers/video/backlight/* to use module_platform_driver()

Convert the drivers in drivers/video/backlight/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> [ep93xx_bl.c]
Cc: Mike Rapoport <mike@compulab.co.il>
Cc: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

backlight: remove ADX backlight device support

Support for the Avionic Design Xanthos backlight device got added in
commit 3b96ea9ef8 ("backlight: Add support for the Avionic Design Xanthos
backlight device.").  That support depends on ARCH_PXA_ADX.  The code that
should have provided that Kconfig symbol never got submitted.  It has
never been possible to even build this driver.  Remove it.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

devfreq: add devfreq maintainer entry

As devfreq is merged at mainline. Also update the maintainer entry.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: spi: update F: patterns

commit ca632f55669 ("spi: reorganize drivers") renamed the files, update
the F: patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: serial:blackfin: update F: pattern

commit 0c6967b5a0 ("serial:blackfin: rename Blackfin serial driver to
bfin_uart.c") renamed the file, update the pattern.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: staging: media: update F: patterns

commit 4860c73804c ("staging: Move media drivers to staging/media") moved
the files, update the F: patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Mauro Carvalho Chehab<mchehab@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update encrypted-keys F: patterns

commit 61cf45d0199 ("encrypted-keys: create encrypted-keys directory")
moved the files, update the patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update greth F: patterns

commit 1fe003fd424 ("greth: Move the Aeroflex Gaisler driver") moved the
files, update the patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kristoffer Glembo <kristoffer@gaisler.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update tulip F: patterns

commit a88394cfb58 ("ewrk3/tulip: Move the DEC - Tulip drivers") moved the
files, update the patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Tobias Ringstrom <tori@unhappy.mine.nu>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: David Davies <davies@maniac.ultranet.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update sdhci F: patterns

commit 38576af1f8c ("mmc: sdhci: make sdhci-of device drivers self
registered") moved the files around.  Update the patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Chris Ball <cjb@laptop.org>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update mfd F: patterns

commit 8959e74399c ("mfd: Delete ab3550 driver") removed the driver,
update the patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update marvell ccic F: patterns

Commit f8fc729870ee ("[media] marvell-cam: Move cafe-ccic into its own
directory") moved the files, update the pattern.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Mauro Carvalho Chehab<mchehab@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update bt8xx gpio F: patterns

Commit c103de240439d ("gpio: reorganize drivers") renamed the file, update
the pattern.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Michael Buesch <m@bues.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update adp gpio F: patterns

Commit c103de240439df ("gpio: reorganize drivers") renamed the files,
update the patterns.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: update various arm F: patterns

Track renames and missing or deleted files.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

get_maintainers.pl: follow renames when looking up commit signers

I happen to have had a commit to various network drivers since the big
renaming/reorg which happened to drivers/net recently.  This means that I
now appear to be in the top few commit signers (by %age) for many of them
so am getting sent all sorts of stuff and people who are involved with the
driver are not.  e.g.  (to pick one at random):

        $ ./scripts/get_maintainer.pl -f drivers/net/ethernet/nvidia/forcedeth.c
        "David S. Miller" <davem@davemloft.net> (commit_signer:5/7=71%)
        Ian Campbell <ian.campbell@citrix.com> (commit_signer:2/7=29%)
        Eric Dumazet <eric.dumazet@gmail.com> (commit_signer:1/7=14%)
        Jeff Kirsher <jeffrey.t.kirsher@intel.com> (commit_signer:1/7=14%)
        Jiri Pirko <jpirko@redhat.com> (commit_signer:1/7=14%)
        netdev@vger.kernel.org (open list:NETWORKING DRIVERS)
        linux-kernel@vger.kernel.org (open list)

With the following patch the renames are followed and the result appears
much more sensible:

        $ ./scripts/get_maintainer.pl -f drivers/net/ethernet/nvidia/forcedeth.c
        "David S. Miller" <davem@davemloft.net> (commit_signer:31/34=91%)
        Joe Perches <joe@perches.com> (commit_signer:11/34=32%)
        Szymon Janc <szymon@janc.net.pl> (commit_signer:5/34=15%)
        Jiri Pirko <jpirko@redhat.com> (commit_signer:3/34=9%)
        Paul <paul.gortmaker@windriver.com> (commit_signer:2/34=6%)
        netdev@vger.kernel.org (open list:NETWORKING DRIVERS)
        linux-kernel@vger.kernel.org (open list)

Signed-off-by: Ian Campbell <Ian.Campbell@citrix.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmalloc.c: change void* into explict vm_struct*

vmap_area->private is void* but we don't use the field for various purpose
but use only for vm_struct.  So change it to a vm_struct* with naming to
improve for readability and type checking.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmscan: fix typo in isolating lru pages

It is not the tag page but the cursor page that we should process, and it
looks a typo.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: test PageSwapBacked in lumpy reclaim

Lumpy reclaim does well to stop at a PageAnon when there's no swap, but
better is to stop at any PageSwapBacked, which includes shmem/tmpfs too.

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c: remove the unused macro lru_to_page

lru_to_page is not used in mm/migrate.c.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c: avoid bogus counter of surplus huge page

If we have to hand back the newly allocated huge page to page allocator,
for any reason, the changed counter should be recovered.

This affects only s390 at present.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mempool: fix first round failure behavior

mempool modifies gfp_mask so that the backing allocator doesn't try too
hard or trigger warning message when there's pool to fall back on.  In
addition, for the first try, it removes __GFP_WAIT and IO, so that it
doesn't trigger reclaim or wait when allocation can be fulfilled from
pool; however, when that allocation fails and pool is empty too, it waits
for the pool to be replenished before retrying.

Allocation which could have succeeded after a bit of reclaim has to wait
on the reserved items and it's not like mempool doesn't retry with
__GFP_WAIT and IO.  It just does that *after* someone returns an element,
pointlessly delaying things.

Fix it by retrying immediately if the first round of allocation attempts
w/o __GFP_WAIT and IO fails.

[akpm@linux-foundation.org: shorten the lock hold time]
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mempool: drop unnecessary and incorrect BUG_ON() from mempool_destroy()

mempool_destroy() is a thin wrapper around free_pool().  The only thing it
adds is BUG_ON(pool->curr_nr != pool->min_nr).  The intention seems to be
to enforce that all allocated elements are freed; however, the BUG_ON()
can't achieve that (it doesn't know anything about objects above min_nr)
and incorrect as mempool_resize() is allowed to leave the pool extended
but not filled.  Furthermore, panicking is way worse than any memory leak
and there are better debug tools to track memory leaks.

Drop the BUG_ON() from mempool_destory() and as that leaves the function
identical to free_pool(), replace it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mempool: fix and document synchronization and memory barrier usage

mempool_alloc/free() use undocumented smp_mb()'s.  The code is slightly
broken and misleading.

The lockless part is in mempool_free().  It wants to determine whether the
item being freed needs to be returned to the pool or backing allocator
without grabbing pool->lock.  Two things need to be guaranteed for correct
operation.

1. pool->curr_nr + #allocated should never dip below pool->min_nr.
2. Waiters shouldn't be left dangling.

For #1, The only necessary condition is that curr_nr visible at free is
from after the allocation of the element being freed (details in the
comment).  For most cases, this is true without any barrier but there can
be fringe cases where the allocated pointer is passed to the freeing task
without going through memory barriers.  To cover this case, wmb is
necessary before returning from allocation and rmb is necessary before
reading curr_nr.  IOW,

ALLOCATING TASK FREEING TASK

update pool state after alloc;
wmb();
pass pointer to freeing task;
read pointer;
rmb();
read pool state to free;

The current code doesn't have wmb after pool update during allocation and
may theoretically, on machines where unlock doesn't behave as full wmb,
lead to pool depletion and deadlock.  smp_wmb() needs to be added after
successful allocation from reserved elements and smp_mb() in
mempool_free() can be replaced with smp_rmb().

For #2, the waiter needs to add itself to waitqueue and then check the
wait condition and the waker needs to update the wait condition and then
wake up.  Because waitqueue operations always go through full spinlock
synchronization, there is no need for extra memory barriers.

Furthermore, mempool_alloc() is already holding pool->lock when it decides
that it needs to wait.  There is no reason to do unlock - add waitqueue -
test condition again.  It can simply add itself to waitqueue while holding
pool->lock and then unlock and sleep.

This patch adds smp_wmb() after successful allocation from reserved pool,
replaces smp_mb() in mempool_free() with smp_rmb() and extend pool->lock
over waitqueue addition.  More importantly, it explains what memory
barriers do and how the lockless testing is correct.

-v2: Oleg pointed out that unlock doesn't imply wmb.  Added explicit
     smp_wmb() after successful allocation from reserved pool and
     updated comments accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c: cleanup comment for migration_entry_wait()

migration_entry_wait() can also be called from hugetlb_fault() now.
Remove the incorrect comment.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mempolicy.c: mpol_equal(): use bool

mpol_equal() logically returns a boolean.  Use a bool type to slightly
improve readability.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Stephen Wilson <wilsons@start.ca>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: hugetlb: fix pgoff computation when unmapping page from vma

The computation for pgoff is incorrect, at least with

(vma->vm_pgoff >> PAGE_SHIFT)

involved.  It is fixed with the available method if HPAGE_SIZE is
concerned in page cache lookup.

[akpm@linux-foundation.org: use vma_hugecache_offset() directly, per Michal]
Signed-off-by: Hillf Danton <dhillf@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c: consider swap space when deciding whether to continue reclaim

It's pointless to continue reclaiming when we have no swap space and lots
of anon pages in the inactive list.

Without this patch, it is possible when swap is disabled to continue
trying to reclaim when there are only anonymous pages in the system even
though that will not make any progress.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: bootmem: try harder to free pages in bulk

The loop that frees pages to the page allocator while bootstrapping tries
to free higher-order blocks only when the starting address is aligned to
that block size.  Otherwise it will free all pages on that node
one-by-one.

Change it to free individual pages up to the first aligned block and then
try higher-order frees from there.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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: bootmem: drop superfluous range check when freeing pages in bulk

The area node_bootmem_map represents is aligned to BITS_PER_LONG, and all
bits in any aligned word of that map valid.  When the represented area
extends beyond the end of the node, the non-existant pages will be marked
as reserved.

As a result, when freeing a page block, doing an explicit range check for
whether that block is within the node's range is redundant as the bitmap
is consulted anyway to see whether all pages in the block are unreserved.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
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: page_alloc: generalize order handling in __free_pages_bootmem()

__free_pages_bootmem() used to special-case higher-order frees to save
individual page checking with free_pages_bulk().

Nowadays, both zero order and non-zero order frees use free_pages(), which
checks each individual page anyway, and so there is little point in making
the distinction anymore.  The higher-order loop will work just fine for
zero order pages.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tracepoint: add tracepoints for debugging oom_score_adj

oom_score_adj is used for guarding processes from OOM-Killer.  One of
problem is that it's inherited at fork().  When a daemon set oom_score_adj
and make children, it's hard to know where the value is set.

This patch adds some tracepoints useful for debugging. This patch adds
3 trace points.
  - creating new task
  - renaming a task (exec)
  - set oom_score_adj

To debug, users need to enable some trace pointer. Maybe filtering is useful as

# EVENT=/sys/kernel/debug/tracing/events/task/
# echo "oom_score_adj != 0" > $EVENT/task_newtask/filter
# echo "oom_score_adj != 0" > $EVENT/task_rename/filter
# echo 1 > $EVENT/enable
# EVENT=/sys/kernel/debug/tracing/events/oom/
# echo 1 > $EVENT/enable

output will be like this.
# grep oom /sys/kernel/debug/tracing/trace
bash-7699  [007] d..3  5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000
bash-7699  [007] ...1  5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000
ls-7729  [003] ...2  5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000
bash-7699  [002] ...1  5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000
grep-7730  [007] ...2  5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: simplify find_vma_prev()

commit 297c5eee37 ("mm: make the vma list be doubly linked") added the
vm_prev member to vm_area_struct.  We can simplify find_vma_prev() by
using it.  Also, this change helps to improve page fault performance
because it has stronger locality of reference.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mremap: enforce rmap src/dst vma ordering in case of vma_merge() succeeding in copy_vma()

migrate was doing an rmap_walk with speculative lock-less access on
pagetables.  That could lead it to not serializing properly against mremap
PT locks.  But a second problem remains in the order of vmas in the
same_anon_vma list used by the rmap_walk.

If vma_merge succeeds in copy_vma, the src vma could be placed after the
dst vma in the same_anon_vma list.  That could still lead to migrate
missing some pte.

This patch adds an anon_vma_moveto_tail() function to force the dst vma at
the end of the list before mremap starts to solve the problem.

If the mremap is very large and there are a lots of parents or childs
sharing the anon_vma root lock, this should still scale better than taking
the anon_vma root lock around every pte copy practically for the whole
duration of mremap.

Update: Hugh noticed special care is needed in the error path where
move_page_tables goes in the reverse direction, a second
anon_vma_moveto_tail() call is needed in the error path.

This program exercises the anon_vma_moveto_tail:

===

int main()
{
static struct timeval oldstamp, newstamp;
long diffsec;
char *p, *p2, *p3, *p4;
if (posix_memalign((void **)&p, 2*1024*1024, SIZE))
perror("memalign"), exit(1);
if (posix_memalign((void **)&p2, 2*1024*1024, SIZE))
perror("memalign"), exit(1);
if (posix_memalign((void **)&p3, 2*1024*1024, SIZE))
perror("memalign"), exit(1);

memset(p, 0xff, SIZE);
printf("%p\n", p);
memset(p2, 0xff, SIZE);
memset(p3, 0x77, 4096);
if (memcmp(p, p2, SIZE))
printf("error\n");
p4 = mremap(p+SIZE/2, SIZE/2, SIZE/2, MREMAP_FIXED|MREMAP_MAYMOVE, p3);
if (p4 != p3)
perror("mremap"), exit(1);
p4 = mremap(p4, SIZE/2, SIZE/2, MREMAP_FIXED|MREMAP_MAYMOVE, p+SIZE/2);
if (p4 != p+SIZE/2)
perror("mremap"), exit(1);
if (memcmp(p, p2, SIZE))
printf("error\n");
printf("ok\n");

return 0;
}
===

$ perf probe -a anon_vma_moveto_tail
Add new event:
  probe:anon_vma_moveto_tail (on anon_vma_moveto_tail)

You can now use it on all perf tools, such as:

        perf record -e probe:anon_vma_moveto_tail -aR sleep 1

$ perf record -e probe:anon_vma_moveto_tail -aR ./anon_vma_moveto_tail
0x7f2ca2800000
ok
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.043 MB perf.data (~1860 samples) ]
$ perf report --stdio
   100.00%  anon_vma_moveto  [kernel.kallsyms]  [k] anon_vma_moveto_tail

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Nai Xia <nai.xia@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pawel Sikora <pluto@agmk.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix off-by-two in __zone_watermark_ok()

Commit 88f5acf88ae6 ("mm: page allocator: adjust the per-cpu counter
threshold when memory is low") changed the form how free_pages is
calculated but it forgot that we used to do free_pages - ((1 << order) -
1) so we ended up with off-by-two when calculating free_pages.

Reported-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bootmem: micro optimize freeing pages in bulk

The first entry of bdata->node_bootmem_map holds the data for
bdata->node_min_pfn up to bdata->node_min_pfn + BITS_PER_LONG - 1.  So the
test for freeing all pages of a single map entry can be slightly relaxed.

Moreover use DIV_ROUND_UP in another place instead of open coding it.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: compaction: push isolate search base of compact control one pfn ahead

After isolated the current pfn will no longer be scanned and isolated if
the next round is necessary, so push the isolate_migratepages search base
of the given compact_control one step ahead.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

btrfs: pass __GFP_WRITE for buffered write page allocations

Tell the page allocator that pages allocated for a buffered write are
expected to become dirty soon.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: filemap: pass __GFP_WRITE from grab_cache_page_write_begin()

Tell the page allocator that pages allocated through
grab_cache_page_write_begin() are expected to become dirty soon.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: try to distribute dirty pages fairly across zones

The maximum number of dirty pages that exist in the system at any time is
determined by a number of pages considered dirtyable and a user-configured
percentage of those, or an absolute number in bytes.

This number of dirtyable pages is the sum of memory provided by all the
zones in the system minus their lowmem reserves and high watermarks, so
that the system can retain a healthy number of free pages without having
to reclaim dirty pages.

But there is a flaw in that we have a zoned page allocator which does not
care about the global state but rather the state of individual memory
zones.  And right now there is nothing that prevents one zone from filling
up with dirty pages while other zones are spared, which frequently leads
to situations where kswapd, in order to restore the watermark of free
pages, does indeed have to write pages from that zone's LRU list.  This
can interfere so badly with IO from the flusher threads that major
filesystems (btrfs, xfs, ext4) mostly ignore write requests from reclaim
already, taking away the VM's only possibility to keep such a zone
balanced, aside from hoping the flushers will soon clean pages from that
zone.

Enter per-zone dirty limits.  They are to a zone's dirtyable memory what
the global limit is to the global amount of dirtyable memory, and try to
make sure that no single zone receives more than its fair share of the
globally allowed dirty pages in the first place.  As the number of pages
considered dirtyable excludes the zones' lowmem reserves and high
watermarks, the maximum number of dirty pages in a zone is such that the
zone can always be balanced without requiring page cleaning.

As this is a placement decision in the page allocator and pages are
dirtied only after the allocation, this patch allows allocators to pass
__GFP_WRITE when they know in advance that the page will be written to and
become dirty soon.  The page allocator will then attempt to allocate from
the first zone of the zonelist - which on NUMA is determined by the task's
NUMA memory policy - that has not exceeded its dirty limit.

At first glance, it would appear that the diversion to lower zones can
increase pressure on them, but this is not the case.  With a full high
zone, allocations will be diverted to lower zones eventually, so it is
more of a shift in timing of the lower zone allocations.  Workloads that
previously could fit their dirty pages completely in the higher zone may
be forced to allocate from lower zones, but the amount of pages that
"spill over" are limited themselves by the lower zones' dirty constraints,
and thus unlikely to become a problem.

For now, the problem of unfair dirty page distribution remains for NUMA
configurations where the zones allowed for allocation are in sum not big
enough to trigger the global dirty limits, wake up the flusher threads and
remedy the situation.  Because of this, an allocation that could not
succeed on any of the considered zones is allowed to ignore the dirty
limits before going into direct reclaim or even failing the allocation,
until a future patch changes the global dirty throttling and flusher
thread activation so that they take individual zone states into account.

Test results

15M DMA + 3246M DMA32 + 504 Normal = 3765M memory
40% dirty ratio
16G USB thumb drive
10 runs of dd if=/dev/zero of=disk/zeroes bs=32k count=$((10 << 15))

seconds nr_vmscan_write
        (stddev)        min|     median|        max
xfs
vanilla:  549.747( 3.492)      0.000|      0.000|      0.000
patched:  550.996( 3.802)      0.000|      0.000|      0.000

fuse-ntfs
vanilla: 1183.094(53.178)  54349.000|  59341.000|  65163.000
patched:  558.049(17.914)      0.000|      0.000|     43.000

btrfs
vanilla:  573.679(14.015) 156657.000| 460178.000| 606926.000
patched:  563.365(11.368)      0.000|      0.000|   1362.000

ext4
vanilla:  561.197(15.782)      0.000|2725438.000|4143837.000
patched:  568.806(17.496)      0.000|      0.000|      0.000

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: writeback: cleanups in preparation for per-zone dirty limits

The next patch will introduce per-zone dirty limiting functions in
addition to the traditional global dirty limiting.

Rename determine_dirtyable_memory() to global_dirtyable_memory() before
adding the zone-specific version, and fix up its documentation.

Also, move the functions to determine the dirtyable memory and the
function to calculate the dirty limit based on that together so that their
relationship is more apparent and that they can be commented on as a
group.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mel@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: exclude reserved pages from dirtyable memory

Per-zone dirty limits try to distribute page cache pages allocated for
writing across zones in proportion to the individual zone sizes, to reduce
the likelihood of reclaim having to write back individual pages from the
LRU lists in order to make progress.

This patch:

The amount of dirtyable pages should not include the full number of free
pages: there is a number of reserved pages that the page allocator and
kswapd always try to keep free.

The closer (reclaimable pages - dirty pages) is to the number of reserved
pages, the more likely it becomes for reclaim to run into dirty pages:

       +----------+ ---
       |   anon   |  |
       +----------+  |
       |          |  |
       |          |  -- dirty limit new    -- flusher new
       |   file   |  |                     |
       |          |  |                     |
       |          |  -- dirty limit old    -- flusher old
       |          |                        |
       +----------+                       --- reclaim
       | reserved |
       +----------+
       |  kernel  |
       +----------+

This patch introduces a per-zone dirty reserve that takes both the lowmem
reserve as well as the high watermark of the zone into account, and a
global sum of those per-zone values that is subtracted from the global
amount of dirtyable pages.  The lowmem reserve is unavailable to page
cache allocations and kswapd tries to keep the high watermark free.  We
don't want to end up in a situation where reclaim has to clean pages in
order to balance zones.

Not treating reserved pages as dirtyable on a global level is only a
conceptual fix.  In reality, dirty pages are not distributed equally
across zones and reclaim runs into dirty pages on a regular basis.

But it is important to get this right before tackling the problem on a
per-zone level, where the distance between reclaim and the dirty pages is
mostly much smaller in absolute numbers.

[akpm@linux-foundation.org: fix highmem build]
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vmscan: add task name to warn_scan_unevictable() messages

If we need to know a usecase, caller program name is critical important.
Show it.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
David Rientjes <rientjes@google.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, debug: test for online nid when allocating on single node

Calling alloc_pages_exact_node() means the allocation only passes the
zonelist of a single node into the page allocator.  If that node isn't
online, it's zonelist may never have been initialized causing a strange
oops that may not immediately be clear.

I recently debugged an issue where node 0 wasn't online and an allocator
was passing 0 to alloc_pages_exact_node() and it resulted in a NULL
pointer on zonelist->_zoneref.  If CONFIG_DEBUG_VM is enabled, though, it
would be nice to catch this a bit earlier.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fadvise: only initiate writeback for specified range with FADV_DONTNEED

Previously POSIX_FADV_DONTNEED would start writeback for the entire file
when the bdi was not write congested.  This negatively impacts performance
if the file contains dirty pages outside of the requested range.  This
change uses __filemap_fdatawrite_range() to only initiate writeback for
the requested range.

Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

slub: min order when debug_guardpage_minorder > 0

Disable slub debug facilities and allocate slabs at minimal order when
debug_guardpage_minorder > 0 to increase probability to catch random
memory corruption by cpu exception.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Stanislaw Gruszka <sgruszka@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>

PM/Hibernate: do not count debug pages as savable

When debugging with CONFIG_DEBUG_PAGEALLOC and debug_guardpage_minorder >
0, we have lot of free pages that are not marked so.  Snapshot code
account them as savable, what cause hibernate memory preallocation
failure.

It is pretty hard to make hibernate allocation succeed with
debug_guardpage_minorder=1.  This change at least make it possible when
system has relatively big amount of RAM.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
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: more intensive memory corruption debugging

With CONFIG_DEBUG_PAGEALLOC configured, the CPU will generate an exception
on access (read,write) to an unallocated page, which permits us to catch
code which corrupts memory.  However the kernel is trying to maximise
memory usage, hence there are usually few free pages in the system and
buggy code usually corrupts some crucial data.

This patch changes the buddy allocator to keep more free/protected pages
and to interlace free/protected and allocated pages to increase the
probability of catching corruption.

When the kernel is compiled with CONFIG_DEBUG_PAGEALLOC,
debug_guardpage_minorder defines the minimum order used by the page
allocator to grant a request.  The requested size will be returned with
the remaining pages used as guard pages.

The default value of debug_guardpage_minorder is zero: no change from
current behaviour.

[akpm@linux-foundation.org: tweak documentation, s/flg/flag/]
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Christoph Lameter <cl@linux-foundation.org>
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>

kernel.h: add BUILD_BUG() macro

We can place this in definitions that we expect the compiler to remove by
dead code elimination.  If this assertion fails, we get a nice error
message at build time.

The GCC function attribute error("message") was added in version 4.3, so
we define a new macro __linktime_error(message) to expand to this for
GCC-4.3 and later.  This will give us an error diagnostic from the
compiler on the line that fails.  For other compilers
__linktime_error(message) expands to nothing, and we have to be content
with a link time error, but at least we will still get a build error.

BUILD_BUG() expands to the undefined function __build_bug_failed() and
will fail at link time if the compiler ever emits code for it.  On GCC-4.3
and later, attribute((error())) is used so that the failure will be noted
at compile time instead.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: DM <dm.n9107@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c: fix virtual address handling in hugetlb fault

handle_mm_fault() passes 'faulted' address to hugetlb_fault().  This
address is not aligned to a hugepage boundary.

Most of the functions for hugetlb pages are aware of that and calculate an
alignment themselves.  However some functions such as
copy_user_huge_page() and clear_huge_page() don't handle alignment by
themselves.

This patch make hugeltb_fault() fix the alignment and pass an aligned
addresss (to address of a faulted hugepage) to functions.

[akpm@linux-foundation.org: use &=]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hugetlb: clarify hugetlb_instantiation_mutex usage

Let's make it clear that we cannot race with other fault handlers due to
hugetlb (global) mutex.  Also make it clear that we want to keep pte_same
checks anayway to have a transition from the global mutex easier.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>