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8 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Wed, 16 Mar 2016 18:51:08 +0000 (11:51 -0700)]
Merge branch 'akpm' (patches from Andrew)

Merge first patch-bomb from Andrew Morton:

 - some misc things

 - ofs2 updates

 - about half of MM

 - checkpatch updates

 - autofs4 update

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (120 commits)
  autofs4: fix string.h include in auto_dev-ioctl.h
  autofs4: use pr_xxx() macros directly for logging
  autofs4: change log print macros to not insert newline
  autofs4: make autofs log prints consistent
  autofs4: fix some white space errors
  autofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()
  autofs4: fix coding style line length in autofs4_wait()
  autofs4: fix coding style problem in autofs4_get_set_timeout()
  autofs4: coding style fixes
  autofs: show pipe inode in mount options
  kallsyms: add support for relative offsets in kallsyms address table
  kallsyms: don't overload absolute symbol type for percpu symbols
  x86: kallsyms: disable absolute percpu symbols on !SMP
  checkpatch: fix another left brace warning
  checkpatch: improve UNSPECIFIED_INT test for bare signed/unsigned uses
  checkpatch: warn on bare unsigned or signed declarations without int
  checkpatch: exclude asm volatile from complex macro check
  mm: memcontrol: drop unnecessary lru locking from mem_cgroup_migrate()
  mm: migrate: consolidate mem_cgroup_migrate() calls
  mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous
  ...

8 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux...
Linus Torvalds [Wed, 16 Mar 2016 17:53:26 +0000 (10:53 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k

Pull m68k updates from Geert Uytterhoeven.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Fix misspellings in comments.
  m68k: Use conventional function parameters for do_sigreturn
  zorro: Use kobj_to_dev()

8 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Linus Torvalds [Wed, 16 Mar 2016 17:47:45 +0000 (10:47 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:

 - Add the CPU id for the new z13s machine

 - Add a s390 specific XOR template for RAID-5 checksumming based on the
   XC instruction.  Remove all other alternatives, XC is always faster

 - The merge of our four different stack tracers into a single one

 - Tidy up the code related to page tables, several large inline
   functions are now out-of-line.  Bloat-o-meter reports ~11K text size
   reduction

 - A binary interface for the priviledged CLP instruction to retrieve
   the hardware view of the installed PCI functions

 - Improvements for the dasd format code

 - Bug fixes and cleanups

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (31 commits)
  s390/pci: enforce fmb page boundary rule
  s390: fix floating pointer register corruption (again)
  s390/cpumf: add missing lpp magic initialization
  s390: Fix misspellings in comments
  s390/mm: split arch/s390/mm/pgtable.c
  s390/mm: uninline pmdp_xxx functions from pgtable.h
  s390/mm: uninline ptep_xxx functions from pgtable.h
  s390/pci: add ioctl interface for CLP
  s390: Use pr_warn instead of pr_warning
  s390/dasd: remove casts to dasd_*_private
  s390/dasd: Refactor dasd format functions
  s390/dasd: Simplify code in format logic
  s390/dasd: Improve dasd format code
  s390/percpu: remove this_cpu_cmpxchg_double_4
  s390/cpumf: Improve guest detection heuristics
  s390/fault: merge report_user_fault implementations
  s390/dis: use correct escape sequence for '%' character
  s390/kvm: simplify set_guest_storage_key
  s390/oprofile: add z13/z13s model numbers
  s390: add z13s model number to z13 elf platform
  ...

8 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt...
Linus Torvalds [Wed, 16 Mar 2016 17:09:30 +0000 (10:09 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32

Pull AVR32 updates from Hans-Christian Egtvedt.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32:
  avr32: fix asm operand constraint in cmpxchg()
  avr32: wire up copy_file_range syscall

8 years agoMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Linus Torvalds [Wed, 16 Mar 2016 16:55:35 +0000 (09:55 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "One of the largest releases for KVM...  Hardly any generic
  changes, but lots of architecture-specific updates.

  ARM:
   - VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
   - PMU support for guests
   - 32bit world switch rewritten in C
   - various optimizations to the vgic save/restore code.

  PPC:
   - enabled KVM-VFIO integration ("VFIO device")
   - optimizations to speed up IPIs between vcpus
   - in-kernel handling of IOMMU hypercalls
   - support for dynamic DMA windows (DDW).

  s390:
   - provide the floating point registers via sync regs;
   - separated instruction vs.  data accesses
   - dirty log improvements for huge guests
   - bugfixes and documentation improvements.

  x86:
   - Hyper-V VMBus hypercall userspace exit
   - alternative implementation of lowest-priority interrupts using
     vector hashing (for better VT-d posted interrupt support)
   - fixed guest debugging with nested virtualizations
   - improved interrupt tracking in the in-kernel IOAPIC
   - generic infrastructure for tracking writes to guest
     memory - currently its only use is to speedup the legacy shadow
     paging (pre-EPT) case, but in the future it will be used for
     virtual GPUs as well
   - much cleanup (LAPIC, kvmclock, MMU, PIT), including ubsan fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (217 commits)
  KVM: x86: remove eager_fpu field of struct kvm_vcpu_arch
  KVM: x86: disable MPX if host did not enable MPX XSAVE features
  arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit
  arm64: KVM: vgic-v3: Reset LRs at boot time
  arm64: KVM: vgic-v3: Do not save an LR known to be empty
  arm64: KVM: vgic-v3: Save maintenance interrupt state only if required
  arm64: KVM: vgic-v3: Avoid accessing ICH registers
  KVM: arm/arm64: vgic-v2: Make GICD_SGIR quicker to hit
  KVM: arm/arm64: vgic-v2: Only wipe LRs on vcpu exit
  KVM: arm/arm64: vgic-v2: Reset LRs at boot time
  KVM: arm/arm64: vgic-v2: Do not save an LR known to be empty
  KVM: arm/arm64: vgic-v2: Move GICH_ELRSR saving to its own function
  KVM: arm/arm64: vgic-v2: Save maintenance interrupt state only if required
  KVM: arm/arm64: vgic-v2: Avoid accessing GICH registers
  KVM: s390: allocate only one DMA page per VM
  KVM: s390: enable STFLE interpretation only if enabled for the guest
  KVM: s390: wake up when the VCPU cpu timer expires
  KVM: s390: step the VCPU timer while in enabled wait
  KVM: s390: protect VCPU cpu timer with a seqcount
  KVM: s390: step VCPU cpu timer during kvm_run ioctl
  ...

8 years agoMerge tag 'edac_for_4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp
Linus Torvalds [Wed, 16 Mar 2016 15:36:55 +0000 (08:36 -0700)]
Merge tag 'edac_for_4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp

Pull EDAC updates from Borislav Petkov:

 - Altera: L2 cache and On-Chip RAM support (Thor Thayer).

 - EDAC: Workqueue handling cleanups (Borislav Petkov).

 - Xgene: Register bus error handling (Loc Ho).

 - Misc small fixes.

* tag 'edac_for_4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
  ARM: socfpga: Enable OCRAM ECC on startup
  ARM: socfpga: Enable L2 cache ECC on startup
  ARM: dts: Add Altera L2 Cache and OCRAM EDAC entries
  EDAC, altera: Add Altera L2 cache and OCRAM support
  EDAC: Use edac_debugfs_remove_recursive() in edac_debugfs_exit()
  EDAC, mpc85xx: Silence unused variable warning
  EDAC: Cleanup/sync workqueue functions
  EDAC: Kill workqueue setup/teardown functions
  EDAC: Balance workqueue setup and teardown
  arm64: Update the APM X-Gene EDAC node with the RB register resource
  EDAC, xgene: Add missing SoC register bus error handling
  Documentation, EDAC: Update xgene binding for missing register bus
  EDAC, amd64_edac: Shift wrapping issue in f1x_get_norm_dct_addr()

8 years agoMerge tag 'leds_for_4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewsk...
Linus Torvalds [Wed, 16 Mar 2016 05:04:53 +0000 (22:04 -0700)]
Merge tag 'leds_for_4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED updates from Jacek Anaszewski:
 "LED core improvements:
   - Fix misleading comment after workqueue removal from drivers
   - Avoid error message when a USB LED device is unplugged
   - Add helpers for calling brightness_set(_blocking)

  LED triggers:
   - Simplify led_trigger_store by using sysfs_streq()

  LED class drivers improvements:
   - Improve wording and formatting in a comment: lp3944
   - Fix return value check in create_gpio_led(): leds-gpio
   - Use GPIOF_OUT_INIT_LOW instead of hardcoded zero: leds-gpio
   - Use devm_led_classdev_register(): leds-lm3533, leds-lm3533,
     leds-lp8788, leds-wm831x-status, leds-s3c24xx, leds-s3c24xx,
     leds-max8997.

  New LED class driver:
   - Add driver for the ISSI IS31FL32xx family of LED controllers.

  Device Tree documentation:
   - of: Add vendor prefixes for Integrated Silicon Solutions Inc.
     (issi) and Si-En Technology (si-en).
   - DT: Add common bindings for Si-En Technology SN3216/18 and
     IS31FL32xx family of LED controllers, since they seem to be the
     same hardware, just rebranded"

* tag 'leds_for_4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds: triggers: simplify led_trigger_store
  leds: max8997: Use devm_led_classdev_register
  leds: da903x: Use devm_led_classdev_register
  leds: s3c24xx: Use devm_led_classdev_register
  leds: wm831x-status: Use devm_led_classdev_register
  leds: lp8788: Use devm_led_classdev_register
  leds: 88pm860x: Use devm_led_classdev_register
  leds: Add SN3218 and SN3216 support to the IS31FL32XX driver
  of: Add vendor prefix for Si-En Technology
  leds: Add driver for the ISSI IS31FL32xx family of LED controllers
  DT: leds: Add binding for the ISSI IS31FL32xx family of LED controllers
  DT: Add vendor prefix for Integrated Silicon Solutions Inc.
  leds: lm3533: Use devm_led_classdev_register
  leds: gpio: Use GPIOF_OUT_INIT_LOW instead of hardcoded zero
  leds: core: add helpers for calling brightness_set(_blocking)
  leds: leds-gpio: Fix return value check in create_gpio_led()
  leds: lp3944: improve wording and formatting in a comment
  leds: core: avoid error message when a USB LED device is unplugged
  leds: core: fix misleading comment after workqueue removal from drivers

8 years agoMerge tag 'rtc-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Linus Torvalds [Wed, 16 Mar 2016 04:58:58 +0000 (21:58 -0700)]
Merge tag 'rtc-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Core:
   - New sysfs interface to set and read clock offset
   - Drivers can now be both I2C and SPI (see pcf2127 and ds3232)

  New drivers:
   - Alphascale ASM9260
   - Epson RX6110SA
   - Maxim max20024 and max77620 (in max77686)
   - Microchip PIC32
   - NXP pcf2129 (in pcf2127)

  Subsystem wide cleanups:
   - remove IRQF_EARLY_RESUME when unecessary

  Drivers:
   - ds1307: clock output, temperature sensor and wakeup-source support
   - ds1685: actually spin forever in poweroff error path
   - ds3232: many cleanups
   - ds3234: merged in ds3232
   - hym8563: fix invalid year calculation
   - max77686: many cleanups
   - max77802 merged in max77686
   - pcf2123: cleanups and offset support
   - pcf85063: cleanups
   - pcf8523: propely handle oscillator stop bit
   - rv3029: many cleanups, trickle charger and temperature sensor support
   - rv8803: convert spin_lock to mutex_lock
   - rx8025: many fixes
   - vr41xx: restore alarm_irq_enable"

* tag 'rtc-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (86 commits)
  rtc: pcf2127: add pcf2129 device id
  rtc: pcf2127: add support for spi interface
  rtc: pcf2127: convert to use regmap
  rtc: rv3029: Add thermometer hwmon support
  rtc: rv3029: Add update_bits helper for eeprom access
  rtc: ds1685: actually spin forever in poweroff error path
  rtc: hym8563: fix invalid year calculation
  rtc: ds3232: use rtc->ops_lock to protect alarm operations
  rtc: ds3232: fix issue when irq is shared several devices
  rtc: ds3232: remove unused UIE code
  rtc: ds3232: add register access error checks
  rtc: ds3232: fix read on /dev/rtc after RTC_AIE_ON
  rtc: merge ds3232 and ds3234
  rtc: ds3232: convert to use regmap
  rtc: pxa: fix Kconfig indentation
  rtc: rv3029: Add device tree property for trickle charger
  rtc: rv3029: Add functions for EEPROM access
  rtc: rv3029: Add i2c register update-bits helper
  rtc: rv3029: Add missing register definitions
  rtc: rv3029: Add "rv3029" I2C device id
  ...

8 years agoMerge tag 'hwmon-for-linus-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Wed, 16 Mar 2016 04:44:47 +0000 (21:44 -0700)]
Merge tag 'hwmon-for-linus-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon updates from Guenter Roeck:
 - New drivers for NSA320 and LTC2990
 - Added support for ADM1278 to adm1275 driver
 - Added support for ncpXXxh103 to ntc_thermistor driver
 - Renamed vexpress hwmon implementation
 - Minor cleanups and improvements

* tag 'hwmon-for-linus-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: Create an NSA320 hardware monitoring driver
  hwmon: Define binding for the nsa320-hwmon driver
  hwmon: (adm1275) Add support for ADM1278
  hwmon: (ntc_thermistor) Add support for ncpXXxh103
  Doc: hwmon: Fix typo "montoring" in hwmon
  ARM: dts: vfxxx: Add iio_hwmon node for ADC temperature channel
  ARM: dts: Change iio_hwmon nodes to use hypen in node names
  hwmon: (iio_hwmon) Allow the driver to accept hypen in device tree node names
  hwmon: Add LTC2990 sensor driver
  hwmon: (vexpress) rename vexpress hwmon implementation

8 years agoMerge tag 'regulator-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...
Linus Torvalds [Wed, 16 Mar 2016 04:34:35 +0000 (21:34 -0700)]
Merge tag 'regulator-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator updates from Mark Brown:
 "This has been an extremely quiet release for the regulator API, aside
  from bugfixes and small enhancements the only thing that really stands
  out are the new drivers for Action Semiconductors ACT8945A, HiSilicon
  HI665x, and the Maxim MAX20024 and MAX77620"

* tag 'regulator-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (46 commits)
  regulator: pwm: Add support to have multiple instance of pwm regulator
  regulator: pwm: Fix calculation of voltage-to-duty cycle
  regulator: of: Use of_property_read_u32() for reading min/max
  regulator: pv88060: fix incorrect clear of event register
  regulator: pv88090: fix incorrect clear of event register
  regulator: max77620: Add support to configure active-discharge
  regulator: core: Add support for active-discharge configuration
  regulator: helper: Add helper to configure active-discharge using regmap
  regulator: core: Add support for active-discharge configuration
  regulator: DT: Add DT property for active-discharge configuration
  regulator: act8865: Specify fixed voltage of 3.3V for ACT8600's REG9
  regulator: act8865: Rename platform_data field to init_data
  regulator: act8865: Remove "static" from local variable
  ASoC: cs4271: add regulator consumer support
  regulator: max77620: Remove duplicate module alias
  regulator: max77620: Eliminate duplicate code
  regulator: max77620: Remove unused fields
  regulator: core: fix crash in error path of regulator_register
  regulator: core: Request GPIO before creating sysfs entries
  regulator: gpio: don't print error on EPROBE_DEFER
  ...

8 years agoMerge tag 'regmap-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...
Linus Torvalds [Wed, 16 Mar 2016 04:22:26 +0000 (21:22 -0700)]
Merge tag 'regmap-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "This has been a very busy release for regmap, not just in cleaning up
  the mess we got ourselves into with the endianness handling but also
  in other areas too:

   - Fixes for the endianness handling so that we now explicitly default
     to little endian (the code used to do this by accident).  This
     fixes handling of explictly specified endianness on big endian
     systems.

   - Optimisation of the implementation of register striding.

   - A refectoring of the _update_bits() code to reduce duplication.

   - Fixes and enhancements for the interrupt implementation which make
     it easier to use in a wider range of systems"

* tag 'regmap-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap: (28 commits)
  regmap: irq: add devm apis for regmap_{add,del}_irq_chip
  regmap: replace regmap_write_bits()
  regmap: irq: Enable irq retriggering for nested irqs
  regmap: add regmap_fields_force_xxx() macros
  regmap: add regmap_field_force_xxx() macros
  regmap: merge regmap_fields_update_bits() into macro
  regmap: merge regmap_fields_write() into macro
  regmap: add regmap_fields_update_bits_base()
  regmap: merge regmap_field_update_bits() into macro
  regmap: merge regmap_field_write() into macro
  regmap: add regmap_field_update_bits_base()
  regmap: merge regmap_update_bits_check_async() into macro
  regmap: merge regmap_update_bits_check() into macro
  regmap: merge regmap_update_bits_async() into macro
  regmap: merge regmap_update_bits() into macro
  regmap: add regmap_update_bits_base()
  regcache: flat: Introduce register strider order
  regcache: Introduce the index parsing API by stride order
  regmap: core: Introduce register stride order
  regmap: irq: add devm apis for regmap_{add,del}_irq_chip
  ...

8 years agoMerge tag 'spi-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Linus Torvalds [Wed, 16 Mar 2016 04:07:33 +0000 (21:07 -0700)]
Merge tag 'spi-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "Not the biggest set of changes for SPI but a bit of a pickup in
  activity on the core:

   - Support for memory mapped read from flash devices via a SPI
     controller.

   - The beginnings of a message rewriting framework in the core which
     should in time allow us to support transforming messages to work
     around the limits of controllers or optimise the performance for
     controllers transparently to calling drivers.

   - Updates to the PXA2xx, the main functional change being to improve
     the ACPI support.

   - A new driver for the Analog Devices AXI SPI engine"

* tag 'spi-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (66 commits)
  spi: Add gfp parameter to kernel-doc to fix build warning
  spi: Fix htmldocs build error due struct spi_replaced_transfers
  spi: rockchip: covert rsd_nsecs to u32 type
  spi: rockchip: header file cleanup
  spi: xilinx: Add devicetree binding for spi-xilinx
  spi: respect the maximum segment size of DMA device
  spi: rockchip: check requesting dma channel with EPROBE_DEFER
  spi: rockchip: migrate to dmaengine_terminate_async
  spi: rockchip: check return value of dmaengine_prep_slave_sg
  spi: core: Fix deadlock when sending messages
  spi/rockchip: fix endian mode for 16-bit transfers
  spi/rockchip: Make sure spi clk is on in rockchip_spi_set_cs
  spi: pxa2xx: Use newer more explicit DMAengine terminate API
  spi: pxa2xx: Add support for Intel Broxton B-Step
  spi: lp-8841: return correct error code from probe
  spi: imx: drop bogus tests for rx/tx bufs in DMA transfer
  spi: imx: set MX51_ECSPI_CTRL_SMC bit in setup function
  spi: imx: make some register defines simpler
  spi: imx: remove unnecessary bit clearing in mx51_ecspi_config
  spi: imx: add support for all SPI word width for DMA
  ...

8 years agoMerge tag 'pinctrl-v4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
Linus Torvalds [Wed, 16 Mar 2016 03:23:13 +0000 (20:23 -0700)]
Merge tag 'pinctrl-v4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl

Pull pin control updates from Linus Walleij:
 "An almost purely driver related set of changes with no major changes
  to the framework, only one patch adding an unlocked version of the
  pinctrl_find_gpio_range_from_pin() library call.

  New drivers:
   - ST Microelectronics STM32 MCU support: this is a non-MMU low-end
     platform for IoT things (etc).
   - Microchip PIC32 MCU support: same story as for STM32.

  New subdrivers:
   - Allwinner SunXi H3 R_PIO controller support.
   - Qualcomm IPQ4019 support.
   - MediaTek MT2701 and MT7623.
   - Allwinner A64

  Non-critical fixes:
   - gpio_disable_free() for the Vybrid.
   - pinctrl single: use a separate lockdep class.

  Misc:
   - Substantial cleanups and rewrites for the Super-H PFC driver and
     subdrivers.
   - Various fixes and cleanups, especially Paul Gortmakers work to make
     nonmodular drivers nonmodular"

* tag 'pinctrl-v4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (75 commits)
  pinctrl: single: Use a separate lockdep class
  drivers: pinctrl: add driver for Allwinner A64 SoC
  pinctrl: Broadcom Northstar2 pinctrl device tree bindings
  pinctrl: amlogic: Make driver independent from two-domain configuration
  pinctrl: amlogic: Separate some pin functions for Meson8 / Meson8b
  pinctrl: at91: use __maybe_unused to hide pm functions
  pinctrl: sh-pfc: core: don't open code of_device_get_match_data()
  pinctrl: uniphier: rename CONFIG options and file names
  pinctrl: sunxi: make A80 explicitly non-modular
  pinctrl: stm32: make explicitly non-modular
  pinctrl: sh-pfc: make explicitly non-modular
  pinctrl: meson: make explicitly non-modular
  pinctrl: pinctrl-mt6397 driver explicitly non-modular
  pinctrl: sunxi: does not need module.h
  pinctrl: pxa2xx: export symbols
  pinctrl: sunxi: Change mux setting on PI irq pins
  pinctrl: sunxi: Remove non existing irq's
  pinctrl: imx: attach iomuxc device to gpr syscon
  pinctrl-bcm2835: Fix cut-and-paste error in "pull" parsing
  pinctrl: lpc1850-scu: document nxp,gpio-pin-interrupt
  ...

8 years agoautofs4: fix string.h include in auto_dev-ioctl.h
Ian Kent [Tue, 15 Mar 2016 21:58:47 +0000 (14:58 -0700)]
autofs4: fix string.h include in auto_dev-ioctl.h

Since including linux/string.h will now do the right thing remove the
conditional check.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: use pr_xxx() macros directly for logging
Ian Kent [Tue, 15 Mar 2016 21:58:45 +0000 (14:58 -0700)]
autofs4: use pr_xxx() macros directly for logging

Use the standard pr_xxx() log macros directly for log prints instead of
the AUTOFS_XXX() macros.

Signed-off-by: Ian Kent <ikent@redhat.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>
8 years agoautofs4: change log print macros to not insert newline
Ian Kent [Tue, 15 Mar 2016 21:58:42 +0000 (14:58 -0700)]
autofs4: change log print macros to not insert newline

Common kernel coding practice is to include the newline of log prints
within the log text rather than hidden away in a macro.

To avoid introducing inconsistencies as changes are made change the log
macros to not include the newline.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: make autofs log prints consistent
Ian Kent [Tue, 15 Mar 2016 21:58:39 +0000 (14:58 -0700)]
autofs4: make autofs log prints consistent

Use the pr_*() print in AUTOFS_*() macros instead of printks and include
the module name in log message macros.  Also use the AUTOFS_*() macros
everywhere instead of raw printks.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: fix some white space errors
Ian Kent [Tue, 15 Mar 2016 21:58:36 +0000 (14:58 -0700)]
autofs4: fix some white space errors

Fix some white space format errors.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()
Ian Kent [Tue, 15 Mar 2016 21:58:33 +0000 (14:58 -0700)]
autofs4: fix invalid ioctl return in autofs4_root_ioctl_unlocked()

The return from an ioctl if an invalid ioctl is passed in should be
EINVAL not ENOSYS.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: fix coding style line length in autofs4_wait()
Ian Kent [Tue, 15 Mar 2016 21:58:30 +0000 (14:58 -0700)]
autofs4: fix coding style line length in autofs4_wait()

The need for this is questionable but checkpatch.pl complains about the
line length and it's a straightfoward change.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: fix coding style problem in autofs4_get_set_timeout()
Ian Kent [Tue, 15 Mar 2016 21:58:28 +0000 (14:58 -0700)]
autofs4: fix coding style problem in autofs4_get_set_timeout()

Refactor autofs4_get_set_timeout() to eliminate coding style error.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs4: coding style fixes
Ian Kent [Tue, 15 Mar 2016 21:58:25 +0000 (14:58 -0700)]
autofs4: coding style fixes

Try and make the coding style completely consistent throughtout the
autofs module and inline with kernel coding style recommendations.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoautofs: show pipe inode in mount options
Stanislav Kinsburskiy [Tue, 15 Mar 2016 21:58:22 +0000 (14:58 -0700)]
autofs: show pipe inode in mount options

This is required for CRIU (Checkpoint Restart In Userspace) to migrate a
mount point when write end in user space is closed.

Below is a brief description of the problem.

To migrate a non-catatonic autofs mount point, one has to restore the
control pipe between kernel and autofs master process.

One of the autofs masters is systemd, which closes pipe write end after
passing it to the kernel with mount call.

To be able to restore the systemd control pipe one has to know which
read pipe end in systemd corresponds to the write pipe end in the
kernel.  The pipe "fd" in mount options is not enough because it was
closed and probably replaced by some other descriptor.

Thus, some other attribute is required to be able to find the read pipe
end.  The best attribute to use to find the correct pipe end is inode
number becuase it's unique for the whole system and can't be reused
while the autofs mount exists.

This attribute can also be used to recognize a situation where an autofs
mount has no master (no process with specified "pgrp" or no file
descriptor with "pipe_ino", specified in autofs mount options).

Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agokallsyms: add support for relative offsets in kallsyms address table
Ard Biesheuvel [Tue, 15 Mar 2016 21:58:19 +0000 (14:58 -0700)]
kallsyms: add support for relative offsets in kallsyms address table

Similar to how relative extables are implemented, it is possible to emit
the kallsyms table in such a way that it contains offsets relative to
some anchor point in the kernel image rather than absolute addresses.

On 64-bit architectures, it cuts the size of the kallsyms address table
in half, since offsets between kernel symbols can typically be expressed
in 32 bits.  This saves several hundreds of kilobytes of permanent
.rodata on average.  In addition, the kallsyms address table is no
longer subject to dynamic relocation when CONFIG_RELOCATABLE is in
effect, so the relocation work done after decompression now doesn't have
to do relocation updates for all these values.  This saves up to 24
bytes (i.e., the size of a ELF64 RELA relocation table entry) per value,
which easily adds up to a couple of megabytes of uncompressed __init
data on ppc64 or arm64.  Even if these relocation entries typically
compress well, the combined size reduction of 2.8 MB uncompressed for a
ppc64_defconfig build (of which 2.4 MB is __init data) results in a ~500
KB space saving in the compressed image.

Since it is useful for some architectures (like x86) to retain the
ability to emit absolute values as well, this patch also adds support
for capturing both absolute and relative values when
KALLSYMS_ABSOLUTE_PERCPU is in effect, by emitting absolute per-cpu
addresses as positive 32-bit values, and addresses relative to the
lowest encountered relative symbol as negative values, which are
subtracted from the runtime address of this base symbol to produce the
actual address.

Support for the above is enabled by default for all architectures except
IA-64 and Tile-GX, whose symbols are too far apart to capture in this
manner.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agokallsyms: don't overload absolute symbol type for percpu symbols
Ard Biesheuvel [Tue, 15 Mar 2016 21:58:15 +0000 (14:58 -0700)]
kallsyms: don't overload absolute symbol type for percpu symbols

Commit c6bda7c988a5 ("kallsyms: fix percpu vars on x86-64 with
relocation") overloaded the 'A' (absolute) symbol type to signify that a
symbol is not subject to dynamic relocation.  However, the original A
type does not imply that at all, and depending on the version of the
toolchain, many A type symbols are emitted that are in fact relative to
the kernel text, i.e., if the kernel is relocated at runtime, these
symbols should be updated as well.

For instance, on sparc32, the following symbols are emitted as absolute
(kindly provided by Guenter Roeck):

  f035a420 A _etext
  f03d9000 A _sdata
  f03de8c4 A jiffies
  f03f8860 A _edata
  f03fc000 A __init_begin
  f041bdc8 A __init_text_end
  f0423000 A __bss_start
  f0423000 A __init_end
  f044457d A __bss_stop
  f044457d A _end

On x86_64, similar behavior can be observed:

  ffffffff81a00000 A __end_rodata_hpage_align
  ffffffff81b19000 A __vvar_page
  ffffffff81d3d000 A _end

Even if only a couple of them pass the symbol range check that results
in them to be taken into account for the final kallsyms symbol table, it
is obvious that 'A' does not mean the symbol does not need to be updated
at relocation time, and overloading its meaning to signify that is
perhaps not a good idea.

So instead, add a new percpu_absolute member to struct sym_entry, and
when --absolute-percpu is in effect, use it to record symbols whose
addresses should be emitted as final values rather than values that
still require relocation at runtime.  That way, we can drop the check
against the 'A' type.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michal Marek <mmarek@suse.cz>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agox86: kallsyms: disable absolute percpu symbols on !SMP
Ard Biesheuvel [Tue, 15 Mar 2016 21:58:12 +0000 (14:58 -0700)]
x86: kallsyms: disable absolute percpu symbols on !SMP

scripts/kallsyms.c has a special --absolute-percpu command line option
which deals with the zero based per cpu offsets that are used when
building for SMP on x86_64.  This means that the option should only be
passed in that case, so add a Kconfig symbol with the correct predicate,
and use that instead.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: fix another left brace warning
Geyslan G. Bem [Tue, 15 Mar 2016 21:58:09 +0000 (14:58 -0700)]
checkpatch: fix another left brace warning

This patch escapes a regex that uses left brace.

Using checkpatch.pl with Perl 5.22.0 generates the warning: "Unescaped
left brace in regex is deprecated, passed through in regex;"

Comment from regcomp.c in Perl source: "Currently we don't warn when the
lbrace is at the start of a construct.  This catches it in the middle of
a literal string, or when it's the first thing after something like
"\b"."

This works as a complement to 4e5d56bd ("checkpatch: fix left brace
warning").

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Eddie Kovsky <ewk@edkovsky.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: improve UNSPECIFIED_INT test for bare signed/unsigned uses
Joe Perches [Tue, 15 Mar 2016 21:58:06 +0000 (14:58 -0700)]
checkpatch: improve UNSPECIFIED_INT test for bare signed/unsigned uses

Improve the test to allow casts to (unsigned) or (signed) to be found
and fixed if desired.

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>
8 years agocheckpatch: warn on bare unsigned or signed declarations without int
Joe Perches [Tue, 15 Mar 2016 21:58:03 +0000 (14:58 -0700)]
checkpatch: warn on bare unsigned or signed declarations without int

Kernel style prefers "unsigned int <foo>" over "unsigned <foo>" and
"signed int <foo>" over "signed <foo>".

Emit a warning for these simple signed/unsigned <foo> declarations.  Fix
it too if desired.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agocheckpatch: exclude asm volatile from complex macro check
Joe Perches [Tue, 15 Mar 2016 21:58:01 +0000 (14:58 -0700)]
checkpatch: exclude asm volatile from complex macro check

asm volatile and all its variants like __asm__ __volatile__ ("<foo>")
are reported as errors with "Macros with with complex values should be
enclosed in parentheses".

Make an exception for these asm volatile macro definitions by converting
the "asm volatile" to "asm_volatile" so it appears as a single function
call and the error isn't reported.

Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Jeff Merkey <linux.mdb@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: memcontrol: drop unnecessary lru locking from mem_cgroup_migrate()
Johannes Weiner [Tue, 15 Mar 2016 21:57:58 +0000 (14:57 -0700)]
mm: memcontrol: drop unnecessary lru locking from mem_cgroup_migrate()

Migration accounting in the memory controller used to have to handle
both oldpage and newpage being on the LRU already; fuse's page cache
replacement used to pass a recycled newpage that had been uncharged but
not freed and removed from the LRU, and the memcg migration code used to
uncharge oldpage to "pass on" the existing charge to newpage.

Nowadays, pages are no longer uncharged when truncated from the page
cache, but rather only at free time, so if a LRU page is recycled in
page cache replacement it'll also still be charged.  And we bail out of
the charge transfer altogether in that case.  Tell commit_charge() that
we know newpage is not on the LRU, to avoid taking the zone->lru_lock
unnecessarily from the migration path.

But also, oldpage is no longer uncharged inside migration.  We only use
oldpage for its page->mem_cgroup and page size, so we don't care about
its LRU state anymore either.  Remove any mention from the kernel doc.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: migrate: consolidate mem_cgroup_migrate() calls
Johannes Weiner [Tue, 15 Mar 2016 21:57:54 +0000 (14:57 -0700)]
mm: migrate: consolidate mem_cgroup_migrate() calls

Rather than scattering mem_cgroup_migrate() calls all over the place,
have a single call from a safe place where every migration operation
eventually ends up in - migrate_page_copy().

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous
Joonsoo Kim [Tue, 15 Mar 2016 21:57:51 +0000 (14:57 -0700)]
mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous

There is a performance drop report due to hugepage allocation and in
there half of cpu time are spent on pageblock_pfn_to_page() in
compaction [1].

In that workload, compaction is triggered to make hugepage but most of
pageblocks are un-available for compaction due to pageblock type and
skip bit so compaction usually fails.  Most costly operations in this
case is to find valid pageblock while scanning whole zone range.  To
check if pageblock is valid to compact, valid pfn within pageblock is
required and we can obtain it by calling pageblock_pfn_to_page().  This
function checks whether pageblock is in a single zone and return valid
pfn if possible.  Problem is that we need to check it every time before
scanning pageblock even if we re-visit it and this turns out to be very
expensive in this workload.

Although we have no way to skip this pageblock check in the system where
hole exists at arbitrary position, we can use cached value for zone
continuity and just do pfn_to_page() in the system where hole doesn't
exist.  This optimization considerably speeds up in above workload.

Before vs After
  Max: 1096 MB/s vs 1325 MB/s
  Min: 635 MB/s 1015 MB/s
  Avg: 899 MB/s 1194 MB/s

Avg is improved by roughly 30% [2].

[1]: http://www.spinics.net/lists/linux-mm/msg97378.html
[2]: https://lkml.org/lkml/2015/12/9/23

[akpm@linux-foundation.org: don't forget to restore zone->contiguous on error path, per Vlastimil]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reported-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Aaron Lu <aaron.lu@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/compaction: pass only pageblock aligned range to pageblock_pfn_to_page
Joonsoo Kim [Tue, 15 Mar 2016 21:57:48 +0000 (14:57 -0700)]
mm/compaction: pass only pageblock aligned range to pageblock_pfn_to_page

pageblock_pfn_to_page() is used to check there is valid pfn and all
pages in the pageblock is in a single zone.  If there is a hole in the
pageblock, passing arbitrary position to pageblock_pfn_to_page() could
cause to skip whole pageblock scanning, instead of just skipping the
hole page.  For deterministic behaviour, it's better to always pass
pageblock aligned range to pageblock_pfn_to_page().  It will also help
further optimization on pageblock_pfn_to_page() in the following patch.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/compaction: fix invalid free_pfn and compact_cached_free_pfn
Joonsoo Kim [Tue, 15 Mar 2016 21:57:45 +0000 (14:57 -0700)]
mm/compaction: fix invalid free_pfn and compact_cached_free_pfn

free_pfn and compact_cached_free_pfn are the pointer that remember
restart position of freepage scanner.  When they are reset or invalid,
we set them to zone_end_pfn because freepage scanner works in reverse
direction.  But, because zone range is defined as [zone_start_pfn,
zone_end_pfn), zone_end_pfn is invalid to access.  Therefore, we should
not store it to free_pfn and compact_cached_free_pfn.  Instead, we need
to store zone_end_pfn - 1 to them.  There is one more thing we should
consider.  Freepage scanner scan reversely by pageblock unit.  If
free_pfn and compact_cached_free_pfn are set to middle of pageblock, it
regards that sitiation as that it already scans front part of pageblock
so we lose opportunity to scan there.  To fix-up, this patch do
round_down() to guarantee that reset position will be pageblock aligned.

Note that thanks to the current pageblock_pfn_to_page() implementation,
actual access to zone_end_pfn doesn't happen until now.  But, following
patch will change pageblock_pfn_to_page() so this patch is needed from
now on.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/memblock.c: remove unnecessary memblock_type variable
Alexander Kuleshov [Tue, 15 Mar 2016 21:57:42 +0000 (14:57 -0700)]
mm/memblock.c: remove unnecessary memblock_type variable

We define struct memblock_type *type in the memblock_add_region() and
memblock_reserve_region() functions only for passing it to the
memlock_add_range() and memblock_reserve_range() functions.  Let's
remove these variables and will pass a type directly.

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agox86: also use debug_pagealloc_enabled() for free_init_pages
Christian Borntraeger [Tue, 15 Mar 2016 21:57:39 +0000 (14:57 -0700)]
x86: also use debug_pagealloc_enabled() for free_init_pages

we want to couple all debugging features with debug_pagealloc_enabled()
and not with the config option CONFIG_DEBUG_PAGEALLOC.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.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>
8 years agos390: query dynamic DEBUG_PAGEALLOC setting
Christian Borntraeger [Tue, 15 Mar 2016 21:57:36 +0000 (14:57 -0700)]
s390: query dynamic DEBUG_PAGEALLOC setting

We can use debug_pagealloc_enabled() to check if we can map the identity
mapping with 1MB/2GB pages as well as to print the current setting in
dump_stack.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agox86: query dynamic DEBUG_PAGEALLOC setting
Christian Borntraeger [Tue, 15 Mar 2016 21:57:33 +0000 (14:57 -0700)]
x86: query dynamic DEBUG_PAGEALLOC setting

We can use debug_pagealloc_enabled() to check if we can map the identity
mapping with 2MB pages.  We can also add the state into the dump_stack
output.

The patch does not touch the code for the 1GB pages, which ignored
CONFIG_DEBUG_PAGEALLOC.  Do we need to fence this as well?

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.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>
8 years agothp: cleanup split_huge_page()
Kirill A. Shutemov [Tue, 15 Mar 2016 21:57:30 +0000 (14:57 -0700)]
thp: cleanup split_huge_page()

After one of bugfixes to freeze_page(), we don't have freezed pages in
rmap, therefore mapcount of all subpages of freezed THP is zero.  And we
have assert for that.

Let's drop code which deal with non-zero mapcount of subpages.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: use linear_page_index() in do_fault()
Matthew Wilcox [Tue, 15 Mar 2016 21:57:28 +0000 (14:57 -0700)]
mm: use linear_page_index() in do_fault()

do_fault() assumes that PAGE_SIZE is the same as PAGE_CACHE_SIZE.  Use
linear_page_index() to calculate pgoff in the correct units.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: remove unnecessary uses of lock_page_memcg()
Johannes Weiner [Tue, 15 Mar 2016 21:57:25 +0000 (14:57 -0700)]
mm: remove unnecessary uses of lock_page_memcg()

There are several users that nest lock_page_memcg() inside lock_page()
to prevent page->mem_cgroup from changing.  But the page lock prevents
pages from moving between cgroups, so that is unnecessary overhead.

Remove lock_page_memcg() in contexts with locked contexts and fix the
debug code in the page stat functions to be okay with the page lock.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.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>
8 years agomm: simplify lock_page_memcg()
Johannes Weiner [Tue, 15 Mar 2016 21:57:22 +0000 (14:57 -0700)]
mm: simplify lock_page_memcg()

Now that migration doesn't clear page->mem_cgroup of live pages anymore,
it's safe to make lock_page_memcg() and the memcg stat functions take
pages, and spare the callers from memcg objects.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.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>
8 years agomm: migrate: do not touch page->mem_cgroup of live pages
Johannes Weiner [Tue, 15 Mar 2016 21:57:19 +0000 (14:57 -0700)]
mm: migrate: do not touch page->mem_cgroup of live pages

Changing a page's memcg association complicates dealing with the page,
so we want to limit this as much as possible.  Page migration e.g.  does
not have to do that.  Just like page cache replacement, it can forcibly
charge a replacement page, and then uncharge the old page when it gets
freed.  Temporarily overcharging the cgroup by a single page is not an
issue in practice, and charging is so cheap nowadays that this is much
preferrable to the headache of messing with live pages.

The only place that still changes the page->mem_cgroup binding of live
pages is when pages move along with a task to another cgroup.  But that
path isolates the page from the LRU, takes the page lock, and the move
lock (lock_page_memcg()).  That means page->mem_cgroup is always stable
in callers that have the page isolated from the LRU or locked.  Lighter
unlocked paths, like writeback accounting, can use lock_page_memcg().

[akpm@linux-foundation.org: fix build]
[vdavydov@virtuozzo.com: fix lockdep splat]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: workingset: per-cgroup cache thrash detection
Johannes Weiner [Tue, 15 Mar 2016 21:57:16 +0000 (14:57 -0700)]
mm: workingset: per-cgroup cache thrash detection

Cache thrash detection (see a528910e12ec "mm: thrash detection-based
file cache sizing" for details) currently only works on the system
level, not inside cgroups.  Worse, as the refaults are compared to the
global number of active cache, cgroups might wrongfully get all their
refaults activated when their pages are hotter than those of others.

Move the refault machinery from the zone to the lruvec, and then tag
eviction entries with the memcg ID.  This makes the thrash detection
work correctly inside cgroups.

[sergey.senozhatsky@gmail.com: do not return from workingset_activation() with locked rcu and page]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: workingset: eviction buckets for bigmem/lowbit machines
Johannes Weiner [Tue, 15 Mar 2016 21:57:13 +0000 (14:57 -0700)]
mm: workingset: eviction buckets for bigmem/lowbit machines

For per-cgroup thrash detection, we need to store the memcg ID inside
the radix tree cookie as well.  However, on 32 bit that doesn't leave
enough bits for the eviction timestamp to cover the necessary range of
recently evicted pages.  The radix tree entry would look like this:

[ RADIX_TREE_EXCEPTIONAL(2) | ZONEID(2) | MEMCGID(16) | EVICTION(12) ]

12 bits means 4096 pages, means 16M worth of recently evicted pages.
But refaults are actionable up to distances covering half of memory.  To
not miss refaults, we have to stretch out the range at the cost of how
precisely we can tell when a page was evicted.  This way we can shave
off lower bits from the eviction timestamp until the necessary range is
covered.  E.g.  grouping evictions into 1M buckets (256 pages) will
stretch the longest representable refault distance to 4G.

This patch implements eviction buckets that are automatically sized
according to the available bits and the necessary refault range, in
preparation for per-cgroup thrash detection.

The maximum actionable distance is currently half of memory, but to
support memory hotplug of up to 200% of boot-time memory, we size the
buckets to cover double the distance.  Beyond that, thrashing won't be
detectable anymore.

During boot, the kernel will print out the exact parameters, like so:

  [    0.113929] workingset: timestamp_bits=12 max_order=18 bucket_order=6

In this example, there are 12 radix entry bits available for the
eviction timestamp, to cover a maximum distance of 2^18 pages (this is a
1G machine).  Consequently, evictions must be grouped into buckets of
2^6 pages, or 256K.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: workingset: separate shadow unpacking and refault calculation
Johannes Weiner [Tue, 15 Mar 2016 21:57:10 +0000 (14:57 -0700)]
mm: workingset: separate shadow unpacking and refault calculation

Per-cgroup thrash detection will need to derive a live memcg from the
eviction cookie, and doing that inside unpack_shadow() will get nasty
with the reference handling spread over two functions.

In preparation, make unpack_shadow() clearly about extracting static
data, and let workingset_refault() do all the higher-level handling.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: workingset: #define radix entry eviction mask
Johannes Weiner [Tue, 15 Mar 2016 21:57:07 +0000 (14:57 -0700)]
mm: workingset: #define radix entry eviction mask

This is a compile-time constant, no need to calculate it on refault.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: memcontrol: generalize locking for the page->mem_cgroup binding
Johannes Weiner [Tue, 15 Mar 2016 21:57:04 +0000 (14:57 -0700)]
mm: memcontrol: generalize locking for the page->mem_cgroup binding

These patches tag the page cache radix tree eviction entries with the
memcg an evicted page belonged to, thus making per-cgroup LRU reclaim
work properly and be as adaptive to new cache workingsets as global
reclaim already is.

This should have been part of the original thrash detection patch
series, but was deferred due to the complexity of those patches.

This patch (of 5):

So far the only sites that needed to exclude charge migration to
stabilize page->mem_cgroup have been per-cgroup page statistics, hence
the name mem_cgroup_begin_page_stat().  But per-cgroup thrash detection
will add another site that needs to ensure page->mem_cgroup lifetime.

Rename these locking functions to the more generic lock_page_memcg() and
unlock_page_memcg().  Since charge migration is a cgroup1 feature only,
we might be able to delete it at some point, and these now easy to
identify locking sites along with it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, vmscan: make zone_reclaimable_pages more precise
Michal Hocko [Tue, 15 Mar 2016 21:57:01 +0000 (14:57 -0700)]
mm, vmscan: make zone_reclaimable_pages more precise

zone_reclaimable_pages() is used in should_reclaim_retry() which uses it
to calculate the target for the watermark check.  This means that
precise numbers are important for the correct decision.
zone_reclaimable_pages uses zone_page_state which can contain stale data
with per-cpu diffs not synced yet (the last vmstat_update might have run
1s in the past).

Use zone_page_state_snapshot() in zone_reclaimable_pages() instead.
None of the current callers is in a hot path where getting the precise
value (which involves per-cpu iteration) would cause an unreasonable
overhead.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/madvise: update comment on sys_madvise()
Naoya Horiguchi [Tue, 15 Mar 2016 21:56:58 +0000 (14:56 -0700)]
mm/madvise: update comment on sys_madvise()

Some new MADV_* advices are not documented in sys_madvise() comment.  So
let's update it.

[akpm@linux-foundation.org: modifications suggested by Michal]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: vmscan: do not clear SHRINKER_NUMA_AWARE if nr_node_ids == 1
Vladimir Davydov [Tue, 15 Mar 2016 21:56:55 +0000 (14:56 -0700)]
mm: vmscan: do not clear SHRINKER_NUMA_AWARE if nr_node_ids == 1

Currently, on shrinker registration we clear SHRINKER_NUMA_AWARE if
there's the only NUMA node present.  The comment states that this will
allow us to save some small loop time later.  It used to be true when
this code was added (see commit 1d3d4437eae1b ("vmscan: per-node
deferred work")), but since commit 6b4f7799c6a57 ("mm: vmscan: invoke
slab shrinkers from shrink_zone()") it doesn't make any difference.
Anyway, running on non-NUMA machine shouldn't make a shrinker NUMA
unaware, so zap this hunk.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoxen_balloon: support memory auto onlining policy
Vitaly Kuznetsov [Tue, 15 Mar 2016 21:56:52 +0000 (14:56 -0700)]
xen_balloon: support memory auto onlining policy

Add support for the newly added kernel memory auto onlining policy to
Xen ballon driver.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Suggested-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomemory-hotplug: add automatic onlining policy for the newly added memory
Vitaly Kuznetsov [Tue, 15 Mar 2016 21:56:48 +0000 (14:56 -0700)]
memory-hotplug: add automatic onlining policy for the newly added memory

Currently, all newly added memory blocks remain in 'offline' state
unless someone onlines them, some linux distributions carry special udev
rules like:

  SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online"

to make this happen automatically.  This is not a great solution for
virtual machines where memory hotplug is being used to address high
memory pressure situations as such onlining is slow and a userspace
process doing this (udev) has a chance of being killed by the OOM killer
as it will probably require to allocate some memory.

Introduce default policy for the newly added memory blocks in
/sys/devices/system/memory/auto_online_blocks file with two possible
values: "offline" which preserves the current behavior and "online"
which causes all newly added memory blocks to go online as soon as
they're added.  The default is "offline".

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/memory.c: make apply_to_page_range() more robust
Mika Penttilä [Tue, 15 Mar 2016 21:56:45 +0000 (14:56 -0700)]
mm/memory.c: make apply_to_page_range() more robust

Arm and arm64 used to trigger this BUG_ON() - this has now been fixed.

But a WARN_ON() here is sufficient to catch future buggy callers.

Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com>
Reviewed-by: Pekka Enberg <penberg@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>
8 years agomm/mempolicy.c: skip VM_HUGETLB and VM_MIXEDMAP VMA for lazy mbind
Liang Chen [Tue, 15 Mar 2016 21:56:42 +0000 (14:56 -0700)]
mm/mempolicy.c: skip VM_HUGETLB and VM_MIXEDMAP VMA for lazy mbind

VM_HUGETLB and VM_MIXEDMAP vma needs to be excluded to avoid compound
pages being marked for migration and unexpected COWs when handling
hugetlb fault.

Thanks to Naoya Horiguchi for reminding me on these checks.

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Signed-off-by: Gavin Guo <gavin.guo@canonical.com>
Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: SeongJae Park <sj38.park@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/memory-failure.c: remove useless "undef"s
Wang Xiaoqiang [Tue, 15 Mar 2016 21:56:39 +0000 (14:56 -0700)]
mm/memory-failure.c: remove useless "undef"s

Remove the useless #undef, since the corresponding #define has already
been removed.

Signed-off-by: Wang Xiaoqiang <wangxq10@lzu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/madvise: pass return code of memory_failure() to userspace
Naoya Horiguchi [Tue, 15 Mar 2016 21:56:36 +0000 (14:56 -0700)]
mm/madvise: pass return code of memory_failure() to userspace

Currently the return value of memory_failure() is not passed to
userspace when madvise(MADV_HWPOISON) is used.  This is inconvenient for
test programs that want to know the result of error handling.  So let's
return it to the caller as we already do in the MADV_SOFT_OFFLINE case.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, sl[au]b: print gfp_flags as strings in slab_out_of_memory()
Vlastimil Babka [Tue, 15 Mar 2016 21:56:33 +0000 (14:56 -0700)]
mm, sl[au]b: print gfp_flags as strings in slab_out_of_memory()

We can now print gfp_flags more human-readable.  Make use of this in
slab_out_of_memory() for SLUB and SLAB.  Also convert the SLAB variant
it to pr_warn() along the way.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/page_poisoning.c: allow for zero poisoning
Laura Abbott [Tue, 15 Mar 2016 21:56:30 +0000 (14:56 -0700)]
mm/page_poisoning.c: allow for zero poisoning

By default, page poisoning uses a poison value (0xaa) on free.  If this
is changed to 0, the page is not only sanitized but zeroing on alloc
with __GFP_ZERO can be skipped as well.  The tradeoff is that detecting
corruption from the poisoning is harder to detect.  This feature also
cannot be used with hibernation since pages are not guaranteed to be
zeroed after hibernation.

Credit to Grsecurity/PaX team for inspiring this work

Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jianyu Zhan <nasa4836@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/page_poison.c: enable PAGE_POISONING as a separate option
Laura Abbott [Tue, 15 Mar 2016 21:56:27 +0000 (14:56 -0700)]
mm/page_poison.c: enable PAGE_POISONING as a separate option

Page poisoning is currently set up as a feature if architectures don't
have architecture debug page_alloc to allow unmapping of pages.  It has
uses apart from that though.  Clearing of the pages on free provides an
increase in security as it helps to limit the risk of information leaks.
Allow page poisoning to be enabled as a separate option independent of
kernel_map pages since the two features do separate work.  Because of
how hiberanation is implemented, the checks on alloc cannot occur if
hibernation is enabled.  The runtime alloc checks can also be enabled
with an option when !HIBERNATION.

Credit to Grsecurity/PaX team for inspiring this work

Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jianyu Zhan <nasa4836@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, debug: move bad flags printing to bad_page()
Vlastimil Babka [Tue, 15 Mar 2016 21:56:24 +0000 (14:56 -0700)]
mm, debug: move bad flags printing to bad_page()

Since bad_page() is the only user of the badflags parameter of
dump_page_badflags(), we can move the code to bad_page() and simplify a
bit.

The dump_page_badflags() function is renamed to __dump_page() and can
still be called separately from dump_page() for temporary debug prints
where page_owner info is not desired.

The only user-visible change is that page->mem_cgroup is printed before
the bad flags.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, page_owner: dump page owner info from dump_page()
Vlastimil Babka [Tue, 15 Mar 2016 21:56:21 +0000 (14:56 -0700)]
mm, page_owner: dump page owner info from dump_page()

The page_owner mechanism is useful for dealing with memory leaks.  By
reading /sys/kernel/debug/page_owner one can determine the stack traces
leading to allocations of all pages, and find e.g.  a buggy driver.

This information might be also potentially useful for debugging, such as
the VM_BUG_ON_PAGE() calls to dump_page().  So let's print the stored
info from dump_page().

Example output:

  page:ffffea000292f1c0 count:1 mapcount:0 mapping:ffff8800b2f6cc18 index:0x91d
  flags: 0x1fffff8001002c(referenced|uptodate|lru|mappedtodisk)
  page dumped because: VM_BUG_ON_PAGE(1)
  page->mem_cgroup:ffff8801392c5000
  page allocated via order 0, migratetype Movable, gfp_mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY)
   [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230
   [<ffffffff811b40c8>] alloc_pages_current+0x88/0x120
   [<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120
   [<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240
   [<ffffffff8116bd05>] ondemand_readahead+0x135/0x260
   [<ffffffff8116be9c>] page_cache_async_readahead+0x6c/0x70
   [<ffffffff811604c2>] generic_file_read_iter+0x3f2/0x760
   [<ffffffff811e0dc7>] __vfs_read+0xa7/0xd0
  page has been migrated, last migrate reason: compaction

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, page_owner: track and print last migrate reason
Vlastimil Babka [Tue, 15 Mar 2016 21:56:18 +0000 (14:56 -0700)]
mm, page_owner: track and print last migrate reason

During migration, page_owner info is now copied with the rest of the
page, so the stacktrace leading to free page allocation during migration
is overwritten.  For debugging purposes, it might be however useful to
know that the page has been migrated since its initial allocation.  This
might happen many times during the lifetime for different reasons and
fully tracking this, especially with stacktraces would incur extra
memory costs.  As a compromise, store and print the migrate_reason of
the last migration that occurred to the page.  This is enough to
distinguish compaction, numa balancing etc.

Example page_owner entry after the patch:

  Page allocated via order 0, mask 0x24200ca(GFP_HIGHUSER_MOVABLE)
  PFN 628753 type Movable Block 1228 type Movable Flags 0x1fffff80040030(dirty|lru|swapbacked)
   [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230
   [<ffffffff811b6325>] alloc_pages_vma+0xb5/0x250
   [<ffffffff81177491>] shmem_alloc_page+0x61/0x90
   [<ffffffff8117a438>] shmem_getpage_gfp+0x678/0x960
   [<ffffffff8117c2b9>] shmem_fallocate+0x329/0x440
   [<ffffffff811de600>] vfs_fallocate+0x140/0x230
   [<ffffffff811df434>] SyS_fallocate+0x44/0x70
   [<ffffffff8158cc2e>] entry_SYSCALL_64_fastpath+0x12/0x71
  Page has been migrated, last migrate reason: compaction

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, page_owner: copy page owner info during migration
Vlastimil Babka [Tue, 15 Mar 2016 21:56:15 +0000 (14:56 -0700)]
mm, page_owner: copy page owner info during migration

The page_owner mechanism stores gfp_flags of an allocation and stack
trace that lead to it.  During page migration, the original information
is practically replaced by the allocation of free page as the migration
target.  Arguably this is less useful and might lead to all the
page_owner info for migratable pages gradually converge towards
compaction or numa balancing migrations.  It has also lead to
inaccuracies such as one fixed by commit e2cfc91120fa ("mm/page_owner:
set correct gfp_mask on page_owner").

This patch thus introduces copying the page_owner info during migration.
However, since the fact that the page has been migrated from its
original place might be useful for debugging, the next patch will
introduce a way to track that information as well.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, page_owner: convert page_owner_inited to static key
Vlastimil Babka [Tue, 15 Mar 2016 21:56:12 +0000 (14:56 -0700)]
mm, page_owner: convert page_owner_inited to static key

CONFIG_PAGE_OWNER attempts to impose negligible runtime overhead when
enabled during compilation, but not actually enabled during runtime by
boot param page_owner=on.  This overhead can be further reduced using
the static key mechanism, which this patch does.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, page_owner: print migratetype of page and pageblock, symbolic flags
Vlastimil Babka [Tue, 15 Mar 2016 21:56:08 +0000 (14:56 -0700)]
mm, page_owner: print migratetype of page and pageblock, symbolic flags

The information in /sys/kernel/debug/page_owner includes the migratetype
of the pageblock the page belongs to.  This is also checked against the
page's migratetype (as declared by gfp_flags during its allocation), and
the page is reported as Fallback if its migratetype differs from the
pageblock's one.  t This is somewhat misleading because in fact fallback
allocation is not the only reason why these two can differ.  It also
doesn't direcly provide the page's migratetype, although it's possible
to derive that from the gfp_flags.

It's arguably better to print both page and pageblock's migratetype and
leave the interpretation to the consumer than to suggest fallback
allocation as the only possible reason.  While at it, we can print the
migratetypes as string the same way as /proc/pagetypeinfo does, as some
of the numeric values depend on kernel configuration.  For that, this
patch moves the migratetype_names array from #ifdef CONFIG_PROC_FS part
of mm/vmstat.c to mm/page_alloc.c and exports it.

With the new format strings for flags, we can now also provide symbolic
page and gfp flags in the /sys/kernel/debug/page_owner file.  This
replaces the positional printing of page flags as single letters, which
might have looked nicer, but was limited to a subset of flags, and
required the user to remember the letters.

Example page_owner entry after the patch:

  Page allocated via order 0, mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY)
  PFN 520 type Movable Block 1 type Movable Flags 0xfffff8001006c(referenced|uptodate|lru|active|mappedtodisk)
   [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230
   [<ffffffff811b4058>] alloc_pages_current+0x88/0x120
   [<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120
   [<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240
   [<ffffffff8116bd05>] ondemand_readahead+0x135/0x260
   [<ffffffff8116bfb1>] page_cache_sync_readahead+0x31/0x50
   [<ffffffff81160523>] generic_file_read_iter+0x453/0x760
   [<ffffffff811e0d57>] __vfs_read+0xa7/0xd0

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, oom: print symbolic gfp_flags in oom warning
Vlastimil Babka [Tue, 15 Mar 2016 21:56:05 +0000 (14:56 -0700)]
mm, oom: print symbolic gfp_flags in oom warning

It would be useful to translate gfp_flags into string representation
when printing in case of an OOM, especially as the flags have been
undergoing some changes recently and the script ./scripts/gfp-translate
needs a matching source version to be accurate.

Example output:

  a.out invoked oom-killer: gfp_mask=0x24280ca(GFP_HIGHUSER_MOVABLE|GFP_ZERO), order=0, om_score_adj=0

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, page_alloc: print symbolic gfp_flags on allocation failure
Vlastimil Babka [Tue, 15 Mar 2016 21:56:02 +0000 (14:56 -0700)]
mm, page_alloc: print symbolic gfp_flags on allocation failure

It would be useful to translate gfp_flags into string representation
when printing in case of an allocation failure, especially as the flags
have been undergoing some changes recently and the script
./scripts/gfp-translate needs a matching source version to be accurate.

Example output:

  stapio: page allocation failure: order:9, mode:0x2080020(GFP_ATOMIC)

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, debug: replace dump_flags() with the new printk formats
Vlastimil Babka [Tue, 15 Mar 2016 21:55:59 +0000 (14:55 -0700)]
mm, debug: replace dump_flags() with the new printk formats

With the new printk format strings for flags, we can get rid of
dump_flags() in mm/debug.c.

This also fixes dump_vma() which used dump_flags() for printing vma
flags.  However dump_flags() did a page-flags specific filtering of bits
higher than NR_PAGEFLAGS in order to remove the zone id part.  For
dump_vma() this resulted in removing several VM_* flags from the
symbolic translation.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, printk: introduce new format string for flags
Vlastimil Babka [Tue, 15 Mar 2016 21:55:56 +0000 (14:55 -0700)]
mm, printk: introduce new format string for flags

In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs.  To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names.  So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g.  sysfs export.

To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv).  Existing users of
dump_flag_names() are converted and simplified.

It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.

[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agomm, tracing: unify mm flags handling in tracepoints and printk
Vlastimil Babka [Tue, 15 Mar 2016 21:55:52 +0000 (14:55 -0700)]
mm, tracing: unify mm flags handling in tracepoints and printk

In tracepoints, it's possible to print gfp flags in a human-friendly
format through a macro show_gfp_flags(), which defines a translation
array and passes is to __print_flags().  Since the following patch will
introduce support for gfp flags printing in printk(), it would be nice
to reuse the array.  This is not straightforward, since __print_flags()
can't simply reference an array defined in a .c file such as mm/debug.c
- it has to be a macro to allow the macro magic to communicate the
format to userspace tools such as trace-cmd.

The solution is to create a macro __def_gfpflag_names which is used both
in show_gfp_flags(), and to define the gfpflag_names[] array in
mm/debug.c.

On the other hand, mm/debug.c also defines translation tables for page
flags and vma flags, and desire was expressed (but not implemented in
this series) to use these also from tracepoints.  Thus, this patch also
renames the events/gfpflags.h file to events/mmflags.h and moves the
table definitions there, using the same macro approach as for gfpflags.
This allows translating all three kinds of mm-specific flags both in
tracepoints and printk.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agotools, perf: make gfp_compact_table up to date
Vlastimil Babka [Tue, 15 Mar 2016 21:55:49 +0000 (14:55 -0700)]
tools, perf: make gfp_compact_table up to date

When updating tracing's show_gfp_flags() I have noticed that perf's
gfp_compact_table is also outdated.  Fill in the missing flags and place
a note in gfp.h to increase chance that future updates are synced.
Convert the __GFP_X flags from "GFP_X" to "__GFP_X" strings in line with
the previous patch.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, tracing: make show_gfp_flags() up to date
Vlastimil Babka [Tue, 15 Mar 2016 21:55:45 +0000 (14:55 -0700)]
mm, tracing: make show_gfp_flags() up to date

The show_gfp_flags() macro provides human-friendly printing of gfp flags
in tracepoints.  However, it is somewhat out of date and missing several
flags.  This patches fills in the missing flags, and distinguishes
properly between GFP_ATOMIC and __GFP_ATOMIC which were both translated
to "GFP_ATOMIC".  More generally, all __GFP_X flags which were
previously printed as GFP_X, are now printed as __GFP_X, since ommiting
the underscores results in output that doesn't actually match the source
code, and can only lead to confusion.  Where both variants are defined
equal (e.g.  _DMA and _DMA32), the variant without underscores are
preferred.

Also add a note in gfp.h so hopefully future changes will be synced
better.

__GFP_MOVABLE is defined twice in include/linux/gfp.h with different
comments.  Leave just the newer one, which was intended to replace the
old one.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.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>
8 years agotracepoints: move trace_print_flags definitions to tracepoint-defs.h
Vlastimil Babka [Tue, 15 Mar 2016 21:55:42 +0000 (14:55 -0700)]
tracepoints: move trace_print_flags definitions to tracepoint-defs.h

The following patch will need to declare array of struct
trace_print_flags in a header.  To prevent this header from pulling in
all of RCU through trace_events.h, move the struct
trace_print_flags{_64} definitions to the new lightweight
tracepoint-defs.h header.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: filemap: avoid unnecessary calls to lock_page when waiting for IO to complete...
Mel Gorman [Tue, 15 Mar 2016 21:55:39 +0000 (14:55 -0700)]
mm: filemap: avoid unnecessary calls to lock_page when waiting for IO to complete during a read

In the generic read paths the kernel looks up a page in the page cache
and if it's up to date, it is used.  If not, the page lock is acquired
to wait for IO to complete and then check the page.  If multiple
processes are waiting on IO, they all serialise against the lock and
duplicate the checks.  This is unnecessary.

The page lock in itself does not give any guarantees to the callers
about the page state as it can be immediately truncated or reclaimed
after the page is unlocked.  It's sufficient to wait_on_page_locked and
then continue if the page is up to date on wakeup.

It is possible that a truncated but up-to-date page is returned but the
reference taken during read prevents it disappearing underneath the
caller and the data is still valid if PageUptodate.

The overall impact is small as even if processes serialise on the lock,
the lock section is tiny once the IO is complete.  Profiles indicated
that unlock_page and friends are generally a tiny portion of a
read-intensive workload.  An artificial test was created that had
instances of dd access a cache-cold file on an ext4 filesystem and
measure how long the read took.

paralleldd
                                    4.4.0                 4.4.0
                                  vanilla             avoidlock
Amean    Elapsd-1          5.28 (  0.00%)        5.15 (  2.50%)
Amean    Elapsd-4          5.29 (  0.00%)        5.17 (  2.12%)
Amean    Elapsd-7          5.28 (  0.00%)        5.18 (  1.78%)
Amean    Elapsd-12         5.20 (  0.00%)        5.33 ( -2.50%)
Amean    Elapsd-21         5.14 (  0.00%)        5.21 ( -1.41%)
Amean    Elapsd-30         5.30 (  0.00%)        5.12 (  3.38%)
Amean    Elapsd-48         5.78 (  0.00%)        5.42 (  6.21%)
Amean    Elapsd-79         6.78 (  0.00%)        6.62 (  2.46%)
Amean    Elapsd-110        9.09 (  0.00%)        8.99 (  1.15%)
Amean    Elapsd-128       10.60 (  0.00%)       10.43 (  1.66%)

The impact is small but intuitively, it makes sense to avoid unnecessary
calls to lock_page.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: filemap: remove redundant code in do_read_cache_page
Mel Gorman [Tue, 15 Mar 2016 21:55:36 +0000 (14:55 -0700)]
mm: filemap: remove redundant code in do_read_cache_page

do_read_cache_page and __read_cache_page duplicate page filler code when
filling the page for the first time.  This patch simply removes the
duplicate logic.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm: fix two typos in comments for to_vmem_altmap()
Andreas Ziegler [Tue, 15 Mar 2016 21:55:33 +0000 (14:55 -0700)]
mm: fix two typos in comments for to_vmem_altmap()

Commit 4b94ffdc4163 ("x86, mm: introduce vmem_altmap to augment
vmemmap_populate()"), introduced the to_vmem_altmap() function.

The comments in this function contain two typos (one misspelling of the
Kconfig option CONFIG_SPARSEMEM_VMEMMAP, and one missing letter 'n'),
let's fix them up.

Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/debug_pagealloc: ask users for default setting of debug_pagealloc
Christian Borntraeger [Tue, 15 Mar 2016 21:55:30 +0000 (14:55 -0700)]
mm/debug_pagealloc: ask users for default setting of debug_pagealloc

Since commit 031bc5743f158 ("mm/debug-pagealloc: make debug-pagealloc
boottime configurable") CONFIG_DEBUG_PAGEALLOC is by default not adding
any page debugging.

This resulted in several unnoticed bugs, e.g.

    https://lkml.kernel.org/g/<569F5E29.3090107@de.ibm.com>
or
    https://lkml.kernel.org/g/<56A20F30.4050705@de.ibm.com>

as this behaviour change was not even documented in Kconfig.

Let's provide a new Kconfig symbol that allows to change the default
back to enabled, e.g.  for debug kernels.  This also makes the change
obvious to kernel packagers.

Let's also change the Kconfig description for CONFIG_DEBUG_PAGEALLOC, to
indicate that there are two stages of overhead.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
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>
8 years agomm/page-writeback: fix dirty_ratelimit calculation
Andrey Ryabinin [Tue, 15 Mar 2016 21:55:27 +0000 (14:55 -0700)]
mm/page-writeback: fix dirty_ratelimit calculation

Calculation of dirty_ratelimit sometimes is not correct.  E.g.  initial
values of dirty_ratelimit == INIT_BW and step == 0, lead to the
following result:

   UBSAN: Undefined behaviour in ../mm/page-writeback.c:1286:7
   shift exponent 25600 is too large for 64-bit type 'long unsigned int'

The fix is straightforward - make step 0 if the shift exponent is too
big.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/page_alloc.c: rework code layout in memmap_init_zone()
Andrew Morton [Tue, 15 Mar 2016 21:55:25 +0000 (14:55 -0700)]
mm/page_alloc.c: rework code layout in memmap_init_zone()

This function is getting full of weird tricks to avoid word-wrapping.
Use a goto to eliminate a tab stop then use the new space

Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/page_alloc.c: introduce kernelcore=mirror option
Taku Izumi [Tue, 15 Mar 2016 21:55:22 +0000 (14:55 -0700)]
mm/page_alloc.c: introduce kernelcore=mirror option

This patch extends existing "kernelcore" option and introduces
kernelcore=mirror option.  By specifying "mirror" instead of specifying
the amount of memory, non-mirrored (non-reliable) region will be
arranged into ZONE_MOVABLE.

[akpm@linux-foundation.org: fix build with CONFIG_HAVE_MEMBLOCK_NODE_MAP=n]
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/page_alloc.c: calculate zone_start_pfn at zone_spanned_pages_in_node()
Taku Izumi [Tue, 15 Mar 2016 21:55:18 +0000 (14:55 -0700)]
mm/page_alloc.c: calculate zone_start_pfn at zone_spanned_pages_in_node()

Xeon E7 v3 based systems supports Address Range Mirroring and UEFI BIOS
complied with UEFI spec 2.5 can notify which ranges are mirrored
(reliable) via EFI memory map.  Now Linux kernel utilize its information
and allocates boot time memory from reliable region.

My requirement is:
  - allocate kernel memory from mirrored region
  - allocate user memory from non-mirrored region

In order to meet my requirement, ZONE_MOVABLE is useful.  By arranging
non-mirrored range into ZONE_MOVABLE, mirrored memory is used for kernel
allocations.

My idea is to extend existing "kernelcore" option and introduces
kernelcore=mirror option.  By specifying "mirror" instead of specifying
the amount of memory, non-mirrored region will be arranged into
ZONE_MOVABLE.

Earlier discussions are at:
 https://lkml.org/lkml/2015/10/9/24
 https://lkml.org/lkml/2015/10/15/9
 https://lkml.org/lkml/2015/11/27/18
 https://lkml.org/lkml/2015/12/8/836

For example, suppose 2-nodes system with the following memory range:

  node 0 [mem 0x0000000000001000-0x000000109fffffff]
  node 1 [mem 0x00000010a0000000-0x000000209fffffff]
and the following ranges are marked as reliable (mirrored):
  [0x0000000000000000-0x0000000100000000]
  [0x0000000100000000-0x0000000180000000]
  [0x0000000800000000-0x0000000880000000]
  [0x00000010a0000000-0x0000001120000000]
  [0x00000017a0000000-0x0000001820000000]

If you specify kernelcore=mirror, ZONE_NORMAL and ZONE_MOVABLE are
arranged like bellow:

 - node 0:
  ZONE_NORMAL : [0x0000000100000000-0x00000010a0000000]
  ZONE_MOVABLE: [0x0000000180000000-0x00000010a0000000]
 - node 1:
  ZONE_NORMAL : [0x00000010a0000000-0x00000020a0000000]
  ZONE_MOVABLE: [0x0000001120000000-0x00000020a0000000]

In overlapped range, pages to be ZONE_MOVABLE in ZONE_NORMAL are treated
as absent pages, and vice versa.

This patch (of 2):

Currently each zone's zone_start_pfn is calculated at
free_area_init_core().  However zone's range is fixed at the time when
invoking zone_spanned_pages_in_node().

This patch changes how each zone->zone_start_pfn is calculated in
zone_spanned_pages_in_node().

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agofs/mpage.c:mpage_readpages(): use lru_to_page() helper
Andrew Morton [Tue, 15 Mar 2016 21:55:15 +0000 (14:55 -0700)]
fs/mpage.c:mpage_readpages(): use lru_to_page() helper

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slub: support left redzone
Joonsoo Kim [Tue, 15 Mar 2016 21:55:12 +0000 (14:55 -0700)]
mm/slub: support left redzone

SLUB already has a redzone debugging feature.  But it is only positioned
at the end of object (aka right redzone) so it cannot catch left oob.
Although current object's right redzone acts as left redzone of next
object, first object in a slab cannot take advantage of this effect.
This patch explicitly adds a left red zone to each object to detect left
oob more precisely.

Background:

Someone complained to me that left OOB doesn't catch even if KASAN is
enabled which does page allocation debugging.  That page is out of our
control so it would be allocated when left OOB happens and, in this
case, we can't find OOB.  Moreover, SLUB debugging feature can be
enabled without page allocator debugging and, in this case, we will miss
that OOB.

Before trying to implement, I expected that changes would be too
complex, but, it doesn't look that complex to me now.  Almost changes
are applied to debug specific functions so I feel okay.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoslub: relax CMPXCHG consistency restrictions
Laura Abbott [Tue, 15 Mar 2016 21:55:09 +0000 (14:55 -0700)]
slub: relax CMPXCHG consistency restrictions

When debug options are enabled, cmpxchg on the page is disabled.  This
is because the page must be locked to ensure there are no false
positives when performing consistency checks.  Some debug options such
as poisoning and red zoning only act on the object itself.  There is no
need to protect other CPUs from modification on only the object.  Allow
cmpxchg to happen with poisoning and red zoning are set on a slab.

Credit to Mathias Krause for the original work which inspired this
series

Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoslub: convert SLAB_DEBUG_FREE to SLAB_CONSISTENCY_CHECKS
Laura Abbott [Tue, 15 Mar 2016 21:55:06 +0000 (14:55 -0700)]
slub: convert SLAB_DEBUG_FREE to SLAB_CONSISTENCY_CHECKS

SLAB_DEBUG_FREE allows expensive consistency checks at free to be turned
on or off.  Expand its use to be able to turn off all consistency
checks.  This gives a nice speed up if you only want features such as
poisoning or tracing.

Credit to Mathias Krause for the original work which inspired this
series

Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoslub: fix/clean free_debug_processing return paths
Laura Abbott [Tue, 15 Mar 2016 21:55:02 +0000 (14:55 -0700)]
slub: fix/clean free_debug_processing return paths

Since commit 19c7ff9ecd89 ("slub: Take node lock during object free
checks") check_object has been incorrectly returning success as it
follows the out label which just returns the node.

Thanks to refactoring, the out and fail paths are now basically the
same.  Combine the two into one and just use a single label.

Credit to Mathias Krause for the original work which inspired this
series

Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoslub: drop lock at the end of free_debug_processing
Laura Abbott [Tue, 15 Mar 2016 21:54:59 +0000 (14:54 -0700)]
slub: drop lock at the end of free_debug_processing

This series takes the suggestion of Christoph Lameter and only focuses
on optimizing the slow path where the debug processing runs.  The two
main optimizations in this series are letting the consistency checks be
skipped and relaxing the cmpxchg restrictions when we are not doing
consistency checks.  With hackbench -g 20 -l 1000 averaged over 100
runs:

Before slub_debug=P
  mean 15.607
  variance .086
  stdev .294

After slub_debug=P
  mean 10.836
  variance .155
  stdev .394

This still isn't as fast as what is in grsecurity unfortunately so there's
still work to be done.  Profiling ___slab_alloc shows that 25-50% of time
is spent in deactivate_slab.  I haven't looked too closely to see if this
is something that can be optimized.  My plan for now is to focus on
getting all of this merged (if appropriate) before digging in to another
task.

This patch (of 4):

Currently, free_debug_processing has a comment "Keep node_lock to preserve
integrity until the object is actually freed".  In actuallity, the lock is
dropped immediately in __slab_free.  Rather than wait until __slab_free
and potentially throw off the unlikely marking, just drop the lock in
__slab_free.  This also lets free_debug_processing take its own copy of
the spinlock flags rather than trying to share the ones from __slab_free.
Since there is no use for the node afterwards, change the return type of
free_debug_processing to return an int like alloc_debug_processing.

Credit to Mathias Krause for the original work which inspired this series

[akpm@linux-foundation.org: fix build]
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: re-implement pfmemalloc support
Joonsoo Kim [Tue, 15 Mar 2016 21:54:56 +0000 (14:54 -0700)]
mm/slab: re-implement pfmemalloc support

Current implementation of pfmemalloc handling in SLAB has some problems.

1) pfmemalloc_active is set to true when there is just one or more
   pfmemalloc slabs in the system, but it is cleared when there is no
   pfmemalloc slab in one arbitrary kmem_cache.  So, pfmemalloc_active
   could be wrongly cleared.

2) Search to partial and free list doesn't happen when non-pfmemalloc
   object are not found in cpu cache.  Instead, allocating new slab
   happens and it is not optimal.

3) Even after sk_memalloc_socks() is disabled, cpu cache would keep
   pfmemalloc objects tagged with SLAB_OBJ_PFMEMALLOC.  It isn't cleared
   if sk_memalloc_socks() is disabled so it could cause problem.

4) If cpu cache is filled with pfmemalloc objects, it would cause slow
   down non-pfmemalloc allocation.

To me, current pointer tagging approach looks complex and fragile so this
patch re-implement whole thing instead of fixing problems one by one.

Design principle for new implementation is that

1) Don't disrupt non-pfmemalloc allocation in fast path even if
   sk_memalloc_socks() is enabled.  It's more likely case than pfmemalloc
   allocation.

2) Ensure that pfmemalloc slab is used only for pfmemalloc allocation.

3) Don't consider performance of pfmemalloc allocation in memory
   deficiency state.

As a result, all pfmemalloc alloc/free in memory tight state will be
handled in slow-path.  If there is non-pfmemalloc free object, it will be
returned first even for pfmemalloc user in fast-path so that performance
of pfmemalloc user isn't affected in normal case and pfmemalloc objects
will be kept as long as possible.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: avoid returning values by reference
Joonsoo Kim [Tue, 15 Mar 2016 21:54:53 +0000 (14:54 -0700)]
mm/slab: avoid returning values by reference

Returing values by reference is bad practice.  Instead, just use
function return value.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Suggested-by: Christoph Lameter <cl@linux.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: introduce new slab management type, OBJFREELIST_SLAB
Joonsoo Kim [Tue, 15 Mar 2016 21:54:50 +0000 (14:54 -0700)]
mm/slab: introduce new slab management type, OBJFREELIST_SLAB

SLAB needs an array to manage freed objects in a slab.  It is only used
if some objects are freed so we can use free object itself as this
array.  This requires additional branch in somewhat critical lock path
to check if it is first freed object or not but that's all we need.
Benefits is that we can save extra memory usage and reduce some
computational overhead by allocating a management array when new slab is
created.

Code change is rather complex than what we can expect from the idea, in
order to handle debugging feature efficiently.  If you want to see core
idea only, please remove '#if DEBUG' block in the patch.

Although this idea can apply to all caches whose size is larger than
management array size, it isn't applied to caches which have a
constructor.  If such cache's object is used for management array,
constructor should be called for it before that object is returned to
user.  I guess that overhead overwhelm benefit in that case so this idea
doesn't applied to them at least now.

For summary, from now on, slab management type is determined by
following logic.

1) if management array size is smaller than object size and no ctor, it
   becomes OBJFREELIST_SLAB.

2) if management array size is smaller than leftover, it becomes
   NORMAL_SLAB which uses leftover as a array.

3) if OFF_SLAB help to save memory than way 4), it becomes OFF_SLAB.
   It allocate a management array from the other cache so memory waste
   happens.

4) others become NORMAL_SLAB.  It uses dedicated internal memory in a
   slab as a management array so it causes memory waste.

In my system, without enabling CONFIG_DEBUG_SLAB, Almost caches become
OBJFREELIST_SLAB and NORMAL_SLAB (using leftover) which doesn't waste
memory.  Following is the result of number of caches with specific slab
management type.

TOTAL = OBJFREELIST + NORMAL(leftover) + NORMAL + OFF

/Before/
126 = 0 + 60 + 25 + 41

/After/
126 = 97 + 12 + 15 + 2

Result shows that number of caches that doesn't waste memory increase
from 60 to 109.

I did some benchmarking and it looks that benefit are more than loss.

Kmalloc: Repeatedly allocate then free test

/Before/
[    0.286809] 1. Kmalloc: Repeatedly allocate then free test
[    1.143674] 100000 times kmalloc(32) -> 116 cycles kfree -> 78 cycles
[    1.441726] 100000 times kmalloc(64) -> 121 cycles kfree -> 80 cycles
[    1.815734] 100000 times kmalloc(128) -> 168 cycles kfree -> 85 cycles
[    2.380709] 100000 times kmalloc(256) -> 287 cycles kfree -> 95 cycles
[    3.101153] 100000 times kmalloc(512) -> 370 cycles kfree -> 117 cycles
[    3.942432] 100000 times kmalloc(1024) -> 413 cycles kfree -> 156 cycles
[    5.227396] 100000 times kmalloc(2048) -> 622 cycles kfree -> 248 cycles
[    7.519793] 100000 times kmalloc(4096) -> 1102 cycles kfree -> 452 cycles

/After/
[    1.205313] 100000 times kmalloc(32) -> 117 cycles kfree -> 78 cycles
[    1.510526] 100000 times kmalloc(64) -> 124 cycles kfree -> 81 cycles
[    1.827382] 100000 times kmalloc(128) -> 130 cycles kfree -> 84 cycles
[    2.226073] 100000 times kmalloc(256) -> 177 cycles kfree -> 92 cycles
[    2.814747] 100000 times kmalloc(512) -> 286 cycles kfree -> 112 cycles
[    3.532952] 100000 times kmalloc(1024) -> 344 cycles kfree -> 141 cycles
[    4.608777] 100000 times kmalloc(2048) -> 519 cycles kfree -> 210 cycles
[    6.350105] 100000 times kmalloc(4096) -> 789 cycles kfree -> 391 cycles

In fact, I tested another idea implementing OBJFREELIST_SLAB with
extendable linked array through another freed object.  It can remove
memory waste completely but it causes more computational overhead in
critical lock path and it seems that overhead outweigh benefit.  So, this
patch doesn't include it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: factor out debugging initialization in cache_init_objs()
Joonsoo Kim [Tue, 15 Mar 2016 21:54:47 +0000 (14:54 -0700)]
mm/slab: factor out debugging initialization in cache_init_objs()

cache_init_objs() will be changed in following patch and current form
doesn't fit well for that change.  So, before doing it, this patch
separates debugging initialization.  This would cause two loop iteration
when debugging is enabled, but, this overhead seems too light than debug
feature itself so effect may not be visible.  This patch will greatly
simplify changes in cache_init_objs() in following patch.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: factor out slab list fixup code
Joonsoo Kim [Tue, 15 Mar 2016 21:54:44 +0000 (14:54 -0700)]
mm/slab: factor out slab list fixup code

Slab list should be fixed up after object is detached from the slab and
this happens at two places.  They do exactly same thing.  They will be
changed in the following patch, so, to reduce code duplication, this
patch factor out them and make it common function.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: make criteria for off slab determination robust and simple
Joonsoo Kim [Tue, 15 Mar 2016 21:54:41 +0000 (14:54 -0700)]
mm/slab: make criteria for off slab determination robust and simple

To become an off slab, there are some constraints to avoid bootstrapping
problem and recursive call.  This can be avoided differently by simply
checking that corresponding kmalloc cache is ready and it's not a off
slab.  It would be more robust because static size checking can be
affected by cache size change or architecture type but dynamic checking
isn't.

One check 'freelist_cache->size > cachep->size / 2' is added to check
benefit of choosing off slab, because, now, there is no size constraint
which ensures enough advantage when selecting off slab.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: do not change cache size if debug pagealloc isn't possible
Joonsoo Kim [Tue, 15 Mar 2016 21:54:38 +0000 (14:54 -0700)]
mm/slab: do not change cache size if debug pagealloc isn't possible

We can fail to setup off slab in some conditions.  Even in this case,
debug pagealloc increases cache size to PAGE_SIZE in advance and it is
waste because debug pagealloc cannot work for it when it isn't the off
slab.  To improve this situation, this patch checks first that this
cache with increased size is suitable for off slab.  It actually
increases cache size when it is suitable for off-slab, so possible waste
is removed.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: clean up cache type determination
Joonsoo Kim [Tue, 15 Mar 2016 21:54:35 +0000 (14:54 -0700)]
mm/slab: clean up cache type determination

Current cache type determination code is open-code and looks not
understandable.  Following patch will introduce one more cache type and
it would make code more complex.  So, before it happens, this patch
abstracts these codes.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: align cache size first before determination of OFF_SLAB candidate
Joonsoo Kim [Tue, 15 Mar 2016 21:54:33 +0000 (14:54 -0700)]
mm/slab: align cache size first before determination of OFF_SLAB candidate

Finding suitable OFF_SLAB candidate is more related to aligned cache
size rather than original size.  Same reasoning can be applied to the
debug pagealloc candidate.  So, this patch moves up alignment fixup to
proper position.  From that point, size is aligned so we can remove some
alignment fixups.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: put the freelist at the end of slab page
Joonsoo Kim [Tue, 15 Mar 2016 21:54:30 +0000 (14:54 -0700)]
mm/slab: put the freelist at the end of slab page

Currently, the freelist is at the front of slab page.  This requires
extra space to meet object alignment requirement.  If we put the
freelist at the end of a slab page, objects could start at page boundary
and will be at correct alignment.  This is possible because freelist has
no alignment constraint itself.

This gives us two benefits: It removes extra memory space for the
freelist alignment and remove complex calculation at cache
initialization step.  I can't think notable drawback here.

I mentioned that this would reduce extra memory space, but, this benefit
is rather theoretical because it can be applied to very few cases.
Following is the example cache type that can get benefit from this
change.

  size align num before after
    32    8  124  4100  4092
    64    8   63  4103  4095
    88    8   46  4102  4094
   272    8   15  4103  4095
   408    8   10  4098  4090
    32   16  124  4108  4092
    64   16   63  4111  4095
    32   32  124  4124  4092
    64   32   63  4127  4095
    96   32   42  4106  4074

before means whole size for objects and aligned freelist before applying
patch and after shows the result of this patch.

Since before is more than 4096, number of object should decrease and
memory waste happens.

Anyway, this patch removes complex calculation so looks beneficial to
me.

[akpm@linux-foundation.org: fix kerneldoc]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/slab: remove object status buffer for DEBUG_SLAB_LEAK
Joonsoo Kim [Tue, 15 Mar 2016 21:54:27 +0000 (14:54 -0700)]
mm/slab: remove object status buffer for DEBUG_SLAB_LEAK

Now, we don't use object status buffer in any setup. Remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>