Commit Graph

14323 Commits

Author SHA1 Message Date
Jiri Kosina 21796b39c9 Merge branches 'for-3.11/wacom-fixed' and 'for-3.11/wiimote' into for-linus 2013-07-04 15:05:02 +02:00
Mark Brown abca37cd2e Merge remote-tracking branch 'regulator/fix/s5m8767' into regulator-linus 2013-07-04 11:14:12 +01:00
Sachin Kamat 489cceeeb8 regulator: max8997: Fix a trivial typo in documentation
Changed volatage to voltage.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-07-04 10:55:50 +01:00
Sachin Kamat 1baa3b4e06 regulator: s5m8767: Fix a trivial typo in documentation
Changed volatage to voltage.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-07-04 10:55:05 +01:00
Sachin Kamat 8eed2641df of/documentation: Update hpd gpio property for exynos_hdmi
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
2013-07-04 15:55:35 +09:00
Linus Torvalds ddcf6600b1 Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon updates from Guenter Roeck:
 - new driver to support GMT G762/G763 pwm fan controllers
 - add support for DS1631, DS1721, and DS1731 to ds1621 driver
 - remove detect function from ds1621 driver as unreliable
 - bug fixes in nct6775, iio_hwmon, and adm1021 drivers
 - remove redundant platform_set_drvdata in various drivers
 - add device tree support to ina2xx driver

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (ds1621) Fix temperature rounding operations
  hwmon: (nct6775) Drop unsupported fan alarm attributes for NCT6775
  hwmon: (nct6775) Fix temperature alarm attributes
  Add support for GMT G762/G763 PWM fan controllers
  hwmon: (ina2xx) Add device tree support to pass the shunt resistor
  hwmon: (ds1621) Update documentation
  hwmon: (ds1621) Add DS1731 chip support to ds1621 driver
  hwmon: (iio_hwmon) add alias table
  hwmon: (adm1021) Do not create min sysfs attributes for LM84
  hwmon: (ds1621) Remove detect function
  hwmon: (ds1621) Add ds1631 chip support to ds1621 driver and documentation
  hwmon: (ds1621) Add ds1721 update interval sysfs attribute
  hwmon: (ds1621) Add ds1721 chip support
  hwmon: (w83627ehf) Remove redundant platform_set_drvdata()
  hwmon: (ntc_thermistor) Remove redundant platform_set_drvdata()
  hwmon: (i5k_amb) Remove redundant platform_set_drvdata()
  hwmon: (coretemp) Remove redundant platform_set_drvdata()
  hwmon: (abituguru3) Remove redundant platform_set_drvdata()
2013-07-03 19:56:35 -07:00
Linus Torvalds c16bfeb264 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds
Pull LED subsystem updates from Bryan Wu:
 - lp55xx device tree updates
 - mc13xxx driver updates
 - some clean up

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
  leds: mc13783: Fix "uninitialized variable" warning
  leds: Convert led class driver from legacy pm ops to dev_pm_ops
  leds: leds-mc13783: Add MC13892 LED support
  leds: leds-mc13783: Prepare driver to support MC13892 LEDs
  leds: renesas-tpu: cleanup a small type issue
  leds: use platform_{get,set}_drvdata()
  leds: leds-gpio: Let device core handle pinctrl
  leds: lp5562: Properly setup of_device_id table
  leds: lp5523: Properly setup of_device_id table
  leds: lp5521: Properly setup of_device_id table
  leds: lp5562: support the device tree feature
  leds: lp55xx: support dynamic channel settings in the device tree structure
  leds: leds-ns2: remove unnecessary platform_set_drvdata()
  leds: leds-mc13783: remove unnecessary platform_set_drvdata()
  leds: leds-gpio: remove unnecessary platform_set_drvdata()
  leds: atmel-pwm: remove unnecessary platform_set_drvdata()
  leds: lp55xx: add support for Device Tree bindings
2013-07-03 19:55:33 -07:00
Linus Torvalds 1286da8bc0 Merge tag 'sound-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound updates from Takashi Iwai:
 "A relative calm release at this time with a flat diffstat.  The only
  significant change in the ALSA core side is the support for more than
  32 card instances, configurable via kconfig.  Other than that, in both
  ASoC and other parts, mostly some improvements and fixes on the driver
  side.

   - hda: More quirks for ALC269-variants on Dell & co, VIA codec fixes
   - hda: Haswell HDMI audio fixes, runtime PM improvements
   - hda: Intel BayTrail support, ALC5505 DSP support
   - es1968: MediaForte M56VAP support
   - usb-audio: Improved support for Yamaha/Roland devices
   - usb-audio: M2Tech hiFace, Audio Advantage Micro II support
   - hdspm: wordclock fixes
   - ASoC: Pending fixes for WM8962
   - ASoC: Cleanups and fixes for Blackfin, SGTL5000 and UX500
   - ASoC: Generalisation of the Bluetooth and HDMI stub drivers
   - ASoC: SSM2518 and RT5640 codec drivers.
   - ASoC: Tegra CPUs with RT5640 machine driver
   - ASoC: AC'97 refactoring bug fixes
   - ASoC: ADAU1701 driver fixes
   - Clean up of *_set_drvdata() in a wide range of drivers"

* tag 'sound-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (284 commits)
  ALSA: vmaster: Fix the regression of missing vmaster hook call
  ALSA: hda - Add Dell SSID to support Headset Mic recording
  ASoC: adau1701: remove control_data assignment
  ASoC: adau1701: more direct regmap usage
  ASoC: ac97: fixup multi-platform AC'97 module build failure
  ASoC: pxa2xx: fixup multi-platform AC'97 build failures
  ASoC: tegra20-ac97: Remove unused variable
  ASoC: tegra20-ac97: Remove duplicate error message
  ALSA: usb-audio: Add Audio Advantage Micro II
  ASoC: tas5086: fix Mid-Z implementation
  ASoC: tas5086: fix TAS5086_CLOCK_CONTROL register size
  ALSA: Replace the magic number 44 with const
  ALSA: hda - Fix the max length of control name in generic parser
  ALSA: hda - Guess what, it's two more Dell headset mic quirks
  ALSA: hda - Yet another Dell headset mic quirk
  ALSA: hda - Add support for ALC5505 DSP power-save mode
  ASoC: mfld: Remove unused variable
  ALSA: usb-audio: add quirks for Roland QUAD/OCTO-CAPTURE
  ALSA: usb-audio: claim autodetected PCM interfaces all at once
  ALSA: usb-audio: remove superfluous Roland quirks
  ...
2013-07-03 19:52:22 -07:00
Linus Torvalds 9e220385c4 Merge branch 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata updates from Tejun Heo:
 "Overview of changes:

   - The rest of maintainer email address updates.

   - Some core updates - more robust default behavior for port
     multipliers, better error reporting for SG_IO commands, and a way
     to better work around now ancient and probably pretty rare PATA ->
     SATA bridges with ATAPI devices.

   - sata_rcar stabilization.

   - Some hardware PCI ID additions and one-off low level driver
     updates."

* 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: (22 commits)
  AHCI: use ATA_BUSY
  libata-zpodd: must use ata_tf_init()
  ahci: AHCI-mode SATA patch for Intel Coleto Creek DeviceIDs
  ata_piix: IDE-mode SATA patch for Intel Coleto Creek DeviceIDs
  libata: cleanup SAT error translation
  ahci: sata: add support for exynos5440 sata
  libata: skip SRST for all SIMG [34]7x port-multipliers
  ahci: remove pmp link online check in FBS EH
  sata highbank: add bit-banged SGPIO driver support
  ahci: make ahci_transmit_led_message into a function pointer
  sata_rcar: fix compilation warning in sata_rcar_thaw()
  sata_highbank: increase retry count but shorten duration for Calxeda controller
  ata: use pci_get_drvdata()
  ipr: qc_fill_rtf() method should not store alternate status register
  sata_rcar: add 'base' local variable to some functions
  sata_rcar: correct 'sata_rcar_sht'
  sata_rcar: kill superfluous code in sata_rcar_bmdma_fill_sg()
  libata: do not limit R-Car SATA driver to shmobile
  ata: use platform_{get,set}_drvdata()
  AHCI: Make distinct names for ports in /proc/interrupts
  ...
2013-07-03 19:49:46 -07:00
Linus Torvalds 7f0ef0267e Merge branch 'akpm' (updates from Andrew Morton)
Merge first patch-bomb from Andrew Morton:
 - various misc bits
 - I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been
   distracted.  There has been quite a bit of activity.
 - About half the MM queue
 - Some backlight bits
 - Various lib/ updates
 - checkpatch updates
 - zillions more little rtc patches
 - ptrace
 - signals
 - exec
 - procfs
 - rapidio
 - nbd
 - aoe
 - pps
 - memstick
 - tools/testing/selftests updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (445 commits)
  tools/testing/selftests: don't assume the x bit is set on scripts
  selftests: add .gitignore for kcmp
  selftests: fix clean target in kcmp Makefile
  selftests: add .gitignore for vm
  selftests: add hugetlbfstest
  self-test: fix make clean
  selftests: exit 1 on failure
  kernel/resource.c: remove the unneeded assignment in function __find_resource
  aio: fix wrong comment in aio_complete()
  drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode
  drivers/memstick/host/r592.c: convert to module_pci_driver
  drivers/memstick/host/jmb38x_ms: convert to module_pci_driver
  pps-gpio: add device-tree binding and support
  drivers/pps/clients/pps-gpio.c: convert to module_platform_driver
  drivers/pps/clients/pps-gpio.c: convert to devm_* helpers
  drivers/parport/share.c: use kzalloc
  Documentation/accounting/getdelays.c: avoid strncpy in accounting tool
  aoe: update internal version number to v83
  aoe: update copyright date
  aoe: perform I/O completions in parallel
  ...
2013-07-03 17:12:13 -07:00
Linus Torvalds 862f001254 Merge tag 'pci-v3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI changes from Bjorn Helgaas:
 "PCI device hotplug
    - Add pci_alloc_dev() interface (Gu Zheng)
    - Add pci_bus_get()/put() for reference counting (Jiang Liu)
    - Fix SR-IOV reference count issues (Jiang Liu)
    - Remove unused acpi_pci_roots list (Jiang Liu)

  MSI
    - Conserve interrupt resources on x86 (Alexander Gordeev)

  AER
    - Force fatal severity when component has been reset (Betty Dall)
    - Reset link below Root Port as well as Downstream Port (Betty Dall)
    - Fix "Firmware first" flag setting (Bjorn Helgaas)
    - Don't parse HEST for non-PCIe devices (Bjorn Helgaas)

  ASPM
    - Warn when we can't disable ASPM as driver requests (Bjorn Helgaas)

  Miscellaneous
    - Add CircuitCo PCI IDs (Darren Hart)
    - Add AMD CZ SATA and SMBus PCI IDs (Shane Huang)
    - Work around Ivytown NTB BAR size issue (Jon Mason)
    - Detect invalid initial BAR values (Kevin Hao)
    - Add pcibios_release_device() (Sebastian Ott)
    - Fix powerpc & sparc PCI_UNKNOWN power state usage (Bjorn Helgaas)"

* tag 'pci-v3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (51 commits)
  MAINTAINERS: Add ACPI folks for ACPI-related things under drivers/pci
  PCI: Add CircuitCo vendor ID and subsystem ID
  PCI: Use pdev->pm_cap instead of pci_find_capability(..,PCI_CAP_ID_PM)
  PCI: Return early on allocation failures to unindent mainline code
  PCI: Simplify IOV implementation and fix reference count races
  PCI: Drop redundant setting of bus->is_added in virtfn_add_bus()
  unicore32/PCI: Remove redundant call of pci_bus_add_devices()
  m68k/PCI: Remove redundant call of pci_bus_add_devices()
  PCI / ACPI / PM: Use correct power state strings in messages
  PCI: Fix comment typo for pcie_pme_remove()
  PCI: Rename pci_release_bus_bridge_dev() to pci_release_host_bridge_dev()
  PCI: Fix refcount issue in pci_create_root_bus() error recovery path
  ia64/PCI: Clean up pci_scan_root_bus() usage
  PCI/AER: Reset link for devices below Root Port or Downstream Port
  ACPI / APEI: Force fatal AER severity when component has been reset
  PCI/AER: Remove "extern" from function declarations
  PCI/AER: Move AER severity defines to aer.h
  PCI/AER: Set dev->__aer_firmware_first only for matching devices
  PCI/AER: Factor out HEST device type matching
  PCI/AER: Don't parse HEST table for non-PCIe devices
  ...
2013-07-03 16:31:35 -07:00
Jan Luebbe c5dbcf8b70 pps-gpio: add device-tree binding and support
Instead of allocating a struct pps_gpio_platform_data in the DT case,
store the necessary information in struct pps_gpio_device_data itself.
This avoids an additional allocation and the ifdef.  It also gets rid of
some indirection.

Also use dev_err instead of pr_err in the changed code.

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:06 -07:00
Kees Cook 8da01af45e Documentation/accounting/getdelays.c: avoid strncpy in accounting tool
Avoid strncpy anti-pattern.

[akpm@linux-foundation.org: remove the str[cpy|dup] altogether]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:06 -07:00
Alexandre Bounine ed5edee2f8 rapidio: documentation update
Update RapidIO documentation files to reflect modularization changes.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Stef van Os <stef.van.os@Prodrive.nl>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:05 -07:00
Zhang Yanfei 987bf6fe3b Documentation/kdump/kdump.txt: remove /dev/oldmem description
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:03 -07:00
Zhang Yanfei a11edb59a0 /dev/oldmem: Remove the interface
/dev/oldmem provides the interface for us to access the "old memory" in
the dump-capture kernel.  Unfortunately, no one actually uses this
interface.

And this interface could actually cause some real problems if used on ia64
where the cached/uncached accesses are mixed.  See the discussion from the
link: https://lkml.org/lkml/2013/4/12/386.

So Eric suggested that we should remove /dev/oldmem as an unused piece of
code.

[akpm@linux-foundation.org: mention /dev/oldmem obsolescence in devices.txt]
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:03 -07:00
Randy Dunlap 4d8eaaae76 docbook: add futexes to kernel-locking docbook
Add Fast User Mutexes (futexes) to kernel-locking docbook.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:01 -07:00
Dan Carpenter b57a0505e7 Documentation/CodingStyle: allow multiple return statements per function
A surprising number of newbies interpret this section to mean that only
one return statement is allowed per function.  Part of the problem is that
the "one return statement per function" rule is an actual style guideline
that people are used to from other projects.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Eduardo Valentin <eduardo.valentin@ti.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:08:01 -07:00
Bernie Thompson 1df0a4711f rtc: add ability to push out an existing wakealarm using sysfs
This adds the ability for the rtc sysfs code to handle += characters at
the beginning of a wakealarm setting string.  This will allow the user
to attempt to push out an existing wakealarm by a provided amount.

In the case that the += characters are provided but the alarm is not
active -EINVAL is returned.

his is useful, at least for my purposes in suspend/resume testing.  The
basic test goes something like:

1. Set a wake alarm from userspace 5 seconds in the future

2. Start the suspend process (echo mem > /sys/power/state)

3. After ~2.5 seconds if userspace is still running (using another
   thread to check this), move the wake alarm 5 more seconds

If the "move" involves an unset of the wakealarm then there's a period
   of time where the system is midway through suspending but has no wake
   alarm.  It will get stuck.

We'd rather not remove the "move" since the idea is to avoid a cancelled
suspend when the alarm fires _during_ suspend.  It is difficult for the
test to tell the difference between a suspend that was cancelled because
the alarm fired too early and a suspend that was

Signed-off-by: Bernie Thompson <bhthompson@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Doug Anderson <dianders@chromium.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:54 -07:00
Bartlomiej Zolnierkiewicz 48a9db462d drivers/dma: remove unused support for MEMSET operations
There have never been any real users of MEMSET operations since they
have been introduced in January 2007 by commit 7405f74bad ("dmaengine:
refactor dmaengine around dma_async_tx_descriptor").  Therefore remove
support for them for now, it can be always brought back when needed.

[sebastian.hesselbarth@gmail.com: fix drivers/dma/mv_xor]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Acked-by: Dan Williams <djbw@fb.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Olof Johansson <olof@lixom.net>
Cc: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:42 -07:00
Mel Gorman 543cc11533 documentation: document the is_dirty_writeback aops callback
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:40 -07:00
Mel Gorman 26c0c5bf38 documentation: update address_space_operations
The documentation for address_space_operations is partially out of date.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:40 -07:00
Li Zefan f968ef1c55 memcg: update TODO list in Documentation
hugetlb cgroup has already been implemented.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rob Landley <rob@landley.net>
Cc: 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>
2013-07-03 16:07:31 -07:00
Pavel Emelyanov 541c237c09 pagemap: prepare to reuse constant bits with page-shift
In order to reuse bits from pagemap entries gracefully, we leave the
entries as is but on pagemap open emit a warning in dmesg, that bits
55-60 are about to change in a couple of releases.  Next, if a user
issues soft-dirty clear command via the clear_refs file (it was disabled
before v3.9) we assume that he's aware of the new pagemap format, note
that fact and report the bits in pagemap in the new manner.

The "migration strategy" looks like this then:

1. existing users are not affected -- they don't touch soft-dirty feature, thus
   see old bits in pagemap, but are warned and have time to fix themselves
2. those who use soft-dirty know about new pagemap format
3. some time soon we get rid of any signs of page-shift in pagemap as well as
   this trick with clear-soft-dirty affecting pagemap format.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:26 -07:00
Pavel Emelyanov 0f8975ec4d mm: soft-dirty bits for user memory changes tracking
The soft-dirty is a bit on a PTE which helps to track which pages a task
writes to.  In order to do this tracking one should

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

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

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

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

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:26 -07:00