sfrench/cifs-2.6.git
2 years agoMerge tag 'vfio-v4.16-rc1' of git://github.com/awilliam/linux-vfio
Linus Torvalds [Thu, 1 Feb 2018 21:18:25 +0000 (13:18 -0800)]
Merge tag 'vfio-v4.16-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Mask INTx from user if pdev->irq is zero (Alexey Kardashevskiy)

 - Capability helper cleanup (Alex Williamson)

 - Allow mmaps overlapping MSI-X vector table with region capability
   exposing this feature (Alexey Kardashevskiy)

 - mdev static cleanups (Xiongwei Song)

* tag 'vfio-v4.16-rc1' of git://github.com/awilliam/linux-vfio:
  vfio: mdev: make a couple of functions and structure vfio_mdev_driver static
  vfio-pci: Allow mapping MSIX BAR
  vfio: Simplify capability helper
  vfio-pci: Mask INTx if a device is not capabable of enabling it

2 years agoMerge tag 'trace-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...
Linus Torvalds [Thu, 1 Feb 2018 21:15:23 +0000 (13:15 -0800)]
Merge tag 'trace-v4.16' of git://git./linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "There's not much changes for the tracing system this release. Mostly
  small clean ups and fixes.

  The biggest change is to how bprintf works. bprintf is used by
  trace_printk() to just save the format and args of a printf call, and
  the formatting is done when the trace buffer is read. This is done to
  keep the formatting out of the fast path (this was recommended by
  you). The issue is when arguments are de-referenced.

  If a pointer is saved, and the format has something like "%*pbl", when
  the buffer is read, it will de-reference the argument then. The
  problem is if the data no longer exists. This can cause the kernel to
  oops.

  The fix for this was to make these de-reference pointes do the
  formatting at the time it is called (the fast path), as this
  guarantees that the data exists (and doesn't change later)"

* tag 'trace-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  vsprintf: Do not have bprintf dereference pointers
  ftrace: Mark function tracer test functions noinline/noclone
  trace_uprobe: Display correct offset in uprobe_events
  tracing: Make sure the parsed string always terminates with '\0'
  tracing: Clear parser->idx if only spaces are read
  tracing: Detect the string nul character when parsing user input string

2 years agoMerge branch 'KASAN-read_word_at_a_time'
Linus Torvalds [Thu, 1 Feb 2018 20:20:53 +0000 (12:20 -0800)]
Merge branch 'KASAN-read_word_at_a_time'

Merge KASAN word-at-a-time fixups from Andrey Ryabinin.

The word-at-a-time optimizations have caused headaches for KASAN, since
the whole point is that we access byte streams in bigger chunks, and
KASAN can be unhappy about the potential extra access at the end of the
string.

We used to have a horrible hack in dcache, and then people got
complaints from the strscpy() case.  This fixes it all up properly, by
adding an explicit helper for the "access byte stream one word at a
time" case.

* emailed patches from Andrey Ryabinin <aryabinin@virtuozzo.com>:
  fs: dcache: Revert "manually unpoison dname after allocation to shut up kasan's reports"
  fs/dcache: Use read_word_at_a_time() in dentry_string_cmp()
  lib/strscpy: Shut up KASAN false-positives in strscpy()
  compiler.h: Add read_word_at_a_time() function.
  compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()

2 years agofs: dcache: Revert "manually unpoison dname after allocation to shut up kasan's reports"
Andrey Ryabinin [Thu, 1 Feb 2018 18:00:52 +0000 (21:00 +0300)]
fs: dcache: Revert "manually unpoison dname after allocation to shut up kasan's reports"

This reverts commit df4c0e36f1b1782b0611a77c52cc240e5c4752dd.

It's no longer needed since dentry_string_cmp() now uses
read_word_at_a_time() to avoid kasan's reports.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agofs/dcache: Use read_word_at_a_time() in dentry_string_cmp()
Andrey Ryabinin [Thu, 1 Feb 2018 18:00:51 +0000 (21:00 +0300)]
fs/dcache: Use read_word_at_a_time() in dentry_string_cmp()

dentry_string_cmp() performs the word-at-a-time reads from 'cs' and may
read slightly more than it was requested in kmallac().  Normally this
would make KASAN to report out-of-bounds access, but this was
workarounded by commit df4c0e36f1b1 ("fs: dcache: manually unpoison
dname after allocation to shut up kasan's reports").

This workaround is not perfect, since it allows out-of-bounds access to
dentry's name for all the code, not just in dentry_string_cmp().

So it would be better to use read_word_at_a_time() instead and revert
commit df4c0e36f1b1.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agolib/strscpy: Shut up KASAN false-positives in strscpy()
Andrey Ryabinin [Thu, 1 Feb 2018 18:00:50 +0000 (21:00 +0300)]
lib/strscpy: Shut up KASAN false-positives in strscpy()

strscpy() performs the word-at-a-time optimistic reads.  So it may may
access the memory past the end of the object, which is perfectly fine
since strscpy() doesn't use that (past-the-end) data and makes sure the
optimistic read won't cross a page boundary.

Use new read_word_at_a_time() to shut up the KASAN.

Note that this potentially could hide some bugs.  In example bellow,
stscpy() will copy more than we should (1-3 extra uninitialized bytes):

        char dst[8];
        char *src;

        src = kmalloc(5, GFP_KERNEL);
        memset(src, 0xff, 5);
        strscpy(dst, src, 8);

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agocompiler.h: Add read_word_at_a_time() function.
Andrey Ryabinin [Thu, 1 Feb 2018 18:00:49 +0000 (21:00 +0300)]
compiler.h: Add read_word_at_a_time() function.

Sometimes we know that it's safe to do potentially out-of-bounds access
because we know it won't cross a page boundary.  Still, KASAN will
report this as a bug.

Add read_word_at_a_time() function which is supposed to be used in such
cases.  In read_word_at_a_time() KASAN performs relaxed check - only the
first byte of access is validated.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agocompiler.h, kasan: Avoid duplicating __read_once_size_nocheck()
Andrey Ryabinin [Thu, 1 Feb 2018 18:00:48 +0000 (21:00 +0300)]
compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()

Instead of having two identical __read_once_size_nocheck() functions
with different attributes, consolidate all the difference in new macro
__no_kasan_or_inline and use it. No functional changes.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoMerge tag 'kconfig-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy...
Linus Torvalds [Thu, 1 Feb 2018 19:45:49 +0000 (11:45 -0800)]
Merge tag 'kconfig-v4.16' of git://git./linux/kernel/git/masahiroy/linux-kbuild

Pull Kconfig updates from Masahiro Yamada:
 "A pretty big batch of Kconfig updates.

  I have to mention the lexer and parser of Kconfig are now built from
  real .l and .y sources. So, flex and bison are the requirement for
  building the kernel. Both of them (unlike gperf) have been stable for
  a long time. This change has been tested several weeks in linux-next,
  and I did not receive any problem report about this.

  Summary:

   - add checks for mistakes, like the choice default is not in choice,
     help is doubled

   - document data structure and complex code

   - fix various memory leaks

   - change Makefile to build lexer and parser instead of using
     pre-generated C files

   - drop 'boolean' keyword, which is equivalent to 'bool'

   - use default 'yy' prefix and remove unneeded Make variables

   - fix gettext() check for xconfig

   - announce that oldnoconfig will be finally removed

   - make 'Selected by:' and 'Implied by' readable in help and search
     result

   - hide silentoldconfig from 'make help' to stop confusing people

   - fix misc things and cleanups"

* tag 'kconfig-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (37 commits)
  kconfig: Remove silentoldconfig from help and docs; fix kconfig/conf's help
  kconfig: make "Selected by:" and "Implied by:" readable
  kconfig: announce removal of oldnoconfig if used
  kconfig: fix make xconfig when gettext is missing
  kconfig: Clarify menu and 'if' dependency propagation
  kconfig: Document 'if' flattening logic
  kconfig: Clarify choice dependency propagation
  kconfig: Document SYMBOL_OPTIONAL logic
  kbuild: remove unnecessary LEX_PREFIX and YACC_PREFIX
  kconfig: use default 'yy' prefix for lexer and parser
  kconfig: make conf_unsaved a local variable of conf_read()
  kconfig: make xfgets() really static
  kconfig: make input_mode static
  kconfig: Warn if there is more than one help text
  kconfig: drop 'boolean' keyword
  kconfig: use bool instead of boolean for type definition attributes, again
  kconfig: Remove menu_end_entry()
  kconfig: Document important expression functions
  kconfig: Document automatic submenu creation code
  kconfig: Fix choice symbol expression leak
  ...

2 years agoMerge tag 'kbuild-misc-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahi...
Linus Torvalds [Thu, 1 Feb 2018 19:43:45 +0000 (11:43 -0800)]
Merge tag 'kbuild-misc-v4.16' of git://git./linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild misc updates from Masahiro Yamada:

 - add snap-pkg target to create Linux kernel snap package

 - make out-of-tree creation of source packages fail correctly

 - improve and fix several semantic patches

* tag 'kbuild-misc-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  Coccinelle: coccicheck: fix typo
  Coccinelle: memdup: drop spurious line
  Coccinelle: kzalloc-simple: Rename kzalloc-simple to zalloc-simple
  Coccinelle: ifnullfree: Trim the warning reported in report mode
  Coccinelle: alloc_cast: Add more memory allocating functions to the list
  Coccinelle: array_size: report even if include is missing
  Coccinelle: kzalloc-simple: Add all zero allocating functions
  kbuild: pkg: make out-of-tree rpm/deb-pkg build immediately fail
  scripts/package: snap-pkg target

2 years agoMerge tag 'kbuild-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy...
Linus Torvalds [Thu, 1 Feb 2018 19:41:09 +0000 (11:41 -0800)]
Merge tag 'kbuild-v4.16' of git://git./linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - terminate the build correctly in case of fixdep errors

 - clean up fixdep

 - suppress packed-not-aligned warnings from GCC-8

 - fix W= handling for extra DTC warnings

* tag 'kbuild-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: fix W= option checks for extra DTC warnings
  Kbuild: suppress packed-not-aligned warning for default setting only
  fixdep: use existing helper to check modular CONFIG options
  fixdep: refactor parse_dep_file()
  fixdep: move global variables to local variables of main()
  fixdep: remove unneeded memcpy() in parse_dep_file()
  fixdep: factor out common code for reading files
  fixdep: use malloc() and read() to load dep_file to buffer
  fixdep: remove unnecessary <arpa/inet.h> inclusion
  fixdep: exit with error code in error branches of do_config_file()

2 years agoMerge tag 'devicetree-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Thu, 1 Feb 2018 18:57:45 +0000 (10:57 -0800)]
Merge tag 'devicetree-for-4.16' of git://git./linux/kernel/git/robh/linux

Pull DeviceTree updates from Rob Herring:

 - Convert to use memblock_virt_alloc in DT code which supports
   bootmem arches. With this we can remove the arch specific
   early_init_dt_alloc_memory_arch() functions.

 - Enable running the DT unittests on UML

 - Use SPDX license tags on DT files

 - Fix early FDT kconfig ifdef logic

 - Clean-up unittest Makefile

 - Fix function comment for of_irq_parse_raw

 - Add missing documentation for linux,initrd-{start,end} properties

 - Clean-up of binding examples using uppercase hex

 - Add trivial devices W83773G and Infineon TLV493D-A1B6

 - Add missing STM32 SoC bindings

 - Various small binding doc fixes

* tag 'devicetree-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (23 commits)
  xtensa: remove arch specific early DT functions
  x86: remove arch specific early_init_dt_alloc_memory_arch
  nios2: remove arch specific early_init_dt_alloc_memory_arch
  mips: remove arch specific early_init_dt_alloc_memory_arch
  metag: remove arch specific early DT functions
  cris: remove arch specific early DT functions
  libfdt: remove unnecessary include directive from <linux/libfdt.h>
  of: unittest: refactor Makefile
  of/fdt: use memblock_virt_alloc for early alloc
  of: Use SPDX license tag for DT files
  of/fdt: Fix #ifdef dependency of early flattree declarations
  dt-bindings: h8300 clocksource: correct spelling of pulse
  dt-bindings: imx6q-pcie: Add required property for i.MX6SX
  mmc: Don't reference Linux-specific OF_GPIO_ACTIVE_LOW flag in DT binding
  dt-bindings: Use lower case hex in unit-addresses
  dt-bindings: display: panel: Fix compatible string for Toshiba LT089AC29000
  dt-bindings: Add Infineon TLV493D-A1B6
  dt-bindings: mailbox: ti,message-manager: Fix interrupt name error
  dt-bindings: chosen: Document linux,initrd-{start,end}
  dt-bindings: arm: document supported STM32 SoC family
  ...

2 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Linus Torvalds [Thu, 1 Feb 2018 18:49:58 +0000 (10:49 -0800)]
Merge branch 'for-linus' of git://git./linux/kernel/git/dtor/input

Pull input layer updates from Dmitry Torokhov:

 - evdev interface has been adjusted to extend the life of timestamps on
   32 bit systems to the year of 2108

 - Synaptics RMI4 driver's PS/2 guest handling ha beed updated to
   improve chances of detecting trackpoints on the pass-through port

 - mms114 touchcsreen controller driver has been updated to support
   generic device properties and work with mms152 cntrollers

 - Goodix driver now supports generic touchscreen properties

 - couple of drivers for AVR32 architecture are gone as the architecture
   support has been removed from the kernel

 - gpio-tilt driver has been removed as there are no mainline users and
   the driver itself is using legacy APIs and relies on platform data

 - MODULE_LINECSE/MODULE_VERSION cleanups

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (45 commits)
  Input: goodix - use generic touchscreen_properties
  Input: mms114 - fix typo in definition
  Input: mms114 - use BIT() macro instead of explicit shifting
  Input: mms114 - replace mdelay with msleep
  Input: mms114 - add support for mms152
  Input: mms114 - drop platform data and use generic APIs
  Input: mms114 - mark as direct input device
  Input: mms114 - do not clobber interrupt trigger
  Input: edt-ft5x06 - fix error handling for factory mode on non-M06
  Input: stmfts - set IRQ_NOAUTOEN to the irq flag
  Input: auo-pixcir-ts - delete an unnecessary return statement
  Input: auo-pixcir-ts - remove custom log for a failed memory allocation
  Input: da9052_tsi - remove unused mutex
  Input: docs - use PROPERTY_ENTRY_U32() directly
  Input: synaptics-rmi4 - log when we create a guest serio port
  Input: synaptics-rmi4 - unmask F03 interrupts when port is opened
  Input: synaptics-rmi4 - do not delete interrupt memory too early
  Input: ad7877 - use managed resource allocations
  Input: stmfts,s6sy671 - add SPDX identifier
  Input: remove atmel-wm97xx touchscreen driver
  ...

2 years agoMerge tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...
Linus Torvalds [Thu, 1 Feb 2018 18:31:17 +0000 (10:31 -0800)]
Merge tag 'char-misc-4.16-rc1' of git://git./linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big pull request for char/misc drivers for 4.16-rc1.

  There's a lot of stuff in here. Three new driver subsystems were added
  for various types of hardware busses:

   - siox
   - slimbus
   - soundwire

  as well as a new vboxguest subsystem for the VirtualBox hypervisor
  drivers.

  There's also big updates from the FPGA subsystem, lots of Android
  binder fixes, the usual handful of hyper-v updates, and lots of other
  smaller driver updates.

  All of these have been in linux-next for a long time, with no reported
  issues"

* tag 'char-misc-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (155 commits)
  char: lp: use true or false for boolean values
  android: binder: use VM_ALLOC to get vm area
  android: binder: Use true and false for boolean values
  lkdtm: fix handle_irq_event symbol for INT_HW_IRQ_EN
  EISA: Delete error message for a failed memory allocation in eisa_probe()
  EISA: Whitespace cleanup
  misc: remove AVR32 dependencies
  virt: vbox: Add error mapping for VERR_INVALID_NAME and VERR_NO_MORE_FILES
  soundwire: Fix a signedness bug
  uio_hv_generic: fix new type mismatch warnings
  uio_hv_generic: fix type mismatch warnings
  auxdisplay: img-ascii-lcd: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  uio_hv_generic: add rescind support
  uio_hv_generic: check that host supports monitor page
  uio_hv_generic: create send and receive buffers
  uio: document uio_hv_generic regions
  doc: fix documentation about uio_hv_generic
  vmbus: add monitor_id and subchannel_id to sysfs per channel
  vmbus: fix ABI documentation
  uio_hv_generic: use ISR callback method
  ...

2 years agoMerge tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Thu, 1 Feb 2018 18:00:28 +0000 (10:00 -0800)]
Merge tag 'driver-core-4.16-rc1' of git://git./linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of "big" driver core patches for 4.16-rc1.

  The majority of the work here is in the firmware subsystem, with
  reworks to try to attempt to make the code easier to handle in the
  long run, but no functional change. There's also some tree-wide sysfs
  attribute fixups with lots of acks from the various subsystem
  maintainers, as well as a handful of other normal fixes and changes.

  And finally, some license cleanups for the driver core and sysfs code.

  All have been in linux-next for a while with no reported issues"

* tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (48 commits)
  device property: Define type of PROPERTY_ENRTY_*() macros
  device property: Reuse property_entry_free_data()
  device property: Move property_entry_free_data() upper
  firmware: Fix up docs referring to FIRMWARE_IN_KERNEL
  firmware: Drop FIRMWARE_IN_KERNEL Kconfig option
  USB: serial: keyspan: Drop firmware Kconfig options
  sysfs: remove DEBUG defines
  sysfs: use SPDX identifiers
  drivers: base: add coredump driver ops
  sysfs: add attribute specification for /sysfs/devices/.../coredump
  test_firmware: fix missing unlock on error in config_num_requests_store()
  test_firmware: make local symbol test_fw_config static
  sysfs: turn WARN() into pr_warn()
  firmware: Fix a typo in fallback-mechanisms.rst
  treewide: Use DEVICE_ATTR_WO
  treewide: Use DEVICE_ATTR_RO
  treewide: Use DEVICE_ATTR_RW
  sysfs.h: Use octal permissions
  component: add debugfs support
  bus: simple-pm-bus: convert bool SIMPLE_PM_BUS to tristate
  ...

2 years agoMerge tag 'staging-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
Linus Torvalds [Thu, 1 Feb 2018 17:51:57 +0000 (09:51 -0800)]
Merge tag 'staging-4.16-rc1' of git://git./linux/kernel/git/gregkh/staging

Pull staging/IIO updates from Greg KH:
 "Here is the big Staging and IIO driver patches for 4.16-rc1.

  There is the normal amount of new IIO drivers added, like all
  releases.

  The networking IPX and the ncpfs filesystem are moved into the staging
  tree, as they are on their way out of the kernel due to lack of use
  anymore.

  The visorbus subsystem finall has started moving out of the staging
  tree to the "real" part of the kernel, and the most and fsl-mc
  codebases are almost ready to move out, that will probably happen for
  4.17-rc1 if all goes well.

  Other than that, there is a bunch of license header cleanups in the
  tree, along with the normal amount of coding style churn that we all
  know and love for this codebase. I also got frustrated at the
  Meltdown/Spectre mess and took it out on the dgnc tty driver, deleting
  huge chunks of it that were never even being used.

  Full details of everything is in the shortlog.

  All of these patches have been in linux-next for a while with no
  reported issues"

* tag 'staging-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (627 commits)
  staging: rtlwifi: remove redundant initialization of 'cfg_cmd'
  staging: rtl8723bs: remove a couple of redundant initializations
  staging: comedi: reformat lines to 80 chars or less
  staging: lustre: separate a connection destroy from free struct kib_conn
  Staging: rtl8723bs: Use !x instead of NULL comparison
  Staging: rtl8723bs: Remove dead code
  Staging: rtl8723bs: Change names to conform to the kernel code
  staging: ccree: Fix missing blank line after declaration
  staging: rtl8188eu: remove redundant initialization of 'pwrcfgcmd'
  staging: rtlwifi: remove unused RTLHALMAC_ST and RTLPHYDM_ST
  staging: fbtft: remove unused FB_TFT_SSD1325 kconfig
  staging: comedi: dt2811: remove redundant initialization of 'ns'
  staging: wilc1000: fix alignments to match open parenthesis
  staging: wilc1000: removed unnecessary defined enums typedef
  staging: wilc1000: remove unnecessary use of parentheses
  staging: rtl8192u: remove redundant initialization of 'timeout'
  staging: sm750fb: fix CamelCase for dispSet var
  staging: lustre: lnet/selftest: fix compile error on UP build
  staging: rtl8723bs: hal_com_phycfg: Remove unneeded semicolons
  staging: rts5208: Fix "seg_no" calculation in reset_ms_card()
  ...

2 years agoMerge tag 'tty-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Linus Torvalds [Thu, 1 Feb 2018 17:46:00 +0000 (09:46 -0800)]
Merge tag 'tty-4.16-rc1' of git://git./linux/kernel/git/gregkh/tty

Pull tty/staging driver updates from Greg KH:
 "Here is the big tty/serial driver update for 4.16-rc1.

  The usual number of various serial driver fixes and updates to try to
  get them to work with crazy hardware configurations (seriously, how
  many different ways are hardware engineers going to come up with to
  hook up a simple UART?)

  There is also some serdev bugfixes and updates, as well as a
  smattering of other small fixes in here.

  All have been in the linux-next tree for a while, with no reported
  issues"

* tag 'tty-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (65 commits)
  tty: serial: exar: Relocate sleep wake-up handling
  tty: fix data race between tty_init_dev and flush of buf
  serial: imx: fix endless loop during suspend
  serial: core: mark port as initialized after successful IRQ change
  serdev: only match serdev devices
  serdev: do not generate modaliases for controllers
  serial: mxs-auart: don't use GPIOF_* with gpiod_get_direction
  serial: 8250_dw: Revert "Improve clock rate setting"
  MAINTAINERS: Add myself as designated reviewer for 8250_dw
  gpio: serial: max310x: Support open-drain configuration for GPIOs
  serdev: Fix serdev_uevent failure on ACPI enumerated serdev-controllers
  serial: 8250_ingenic: Parse earlycon options
  serial: 8250_ingenic: Add support for the JZ4770 SoC
  serial: core: Make uart_parse_options take const char* argument
  serial: 8250_of: fix return code when probe function fails to get reset
  serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS
  serial: 8250_uniphier: fix error return code in uniphier_uart_probe()
  tty: n_gsm: Allow ADM response in addition to UA for control dlci
  tty: omap-serial: Fix initial on-boot RTS GPIO level
  tty: serial: jsm: Add one check against NULL pointer dereference
  ...

2 years agoMerge tag 'usb-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Linus Torvalds [Thu, 1 Feb 2018 17:40:49 +0000 (09:40 -0800)]
Merge tag 'usb-4.16-rc1' of git://git./linux/kernel/git/gregkh/usb

Pull USB/PHY updates from Greg KH:
 "Here is the big USB and PHY driver update for 4.16-rc1.

  Along with the normally expected XHCI, MUSB, and Gadget driver
  patches, there are some PHY driver fixes, license cleanups, sysfs
  attribute cleanups, usbip changes, and a raft of other smaller fixes
  and additions.

  Full details are in the shortlog.

  All of these have been in the linux-next tree for a long time with no
  reported issues"

* tag 'usb-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (137 commits)
  USB: serial: pl2303: new device id for Chilitag
  USB: misc: fix up some remaining DEVICE_ATTR() usages
  USB: musb: fix up one odd DEVICE_ATTR() usage
  USB: atm: fix up some remaining DEVICE_ATTR() usage
  USB: move many drivers to use DEVICE_ATTR_WO
  USB: move many drivers to use DEVICE_ATTR_RO
  USB: move many drivers to use DEVICE_ATTR_RW
  USB: misc: chaoskey: Use true and false for boolean values
  USB: storage: remove old wording about how to submit a change
  USB: storage: remove invalid URL from drivers
  usb: ehci-omap: don't complain on -EPROBE_DEFER when no PHY found
  usbip: list: don't list devices attached to vhci_hcd
  usbip: prevent bind loops on devices attached to vhci_hcd
  USB: serial: remove redundant initializations of 'mos_parport'
  usb/gadget: Fix "high bandwidth" check in usb_gadget_ep_match_desc()
  usb: gadget: compress return logic into one line
  usbip: vhci_hcd: update 'status' file header and format
  USB: serial: simple: add Motorola Tetra driver
  CDC-ACM: apply quirk for card reader
  usb: option: Add support for FS040U modem
  ...

2 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide
Linus Torvalds [Thu, 1 Feb 2018 17:37:30 +0000 (09:37 -0800)]
Merge git://git./linux/kernel/git/davem/ide

Pull small IDE cleanup from David Miller.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide:
  ide: remove duplicated assignment to 'cursg'

2 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next
Linus Torvalds [Thu, 1 Feb 2018 17:34:52 +0000 (09:34 -0800)]
Merge git://git./linux/kernel/git/davem/sparc-next

Pull sparc updates from David Miller:
 "Of note is the addition of a driver for the Data Analytics
  Accelerator, and some small cleanups"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next:
  oradax: Fix return value check in dax_attach()
  sparc: vDSO: remove an extra tab
  sparc64: drop unneeded compat include
  sparc64: Oracle DAX driver
  sparc64: Oracle DAX infrastructure

2 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Linus Torvalds [Thu, 1 Feb 2018 17:31:04 +0000 (09:31 -0800)]
Merge branch 'for-linus' of git://git./linux/kernel/git/s390/linux

Pull s390 updates from Martin Schwidefsky:
 "Bug fixes, small improvements and one notable change: the system call
  table and the unistd.h header are now generated automatically with a
  shell script from a text file"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/decompressor: discard __ksymtab and .eh_frame sections
  s390: fix handling of -1 in set{,fs}[gu]id16 syscalls
  s390/tools: generate header files in arch/s390/include/generated/
  s390/syscalls: use generated syscall_table.h and unistd.h header files
  s390/syscalls: add Makefile to generate system call header files
  s390/syscalls: add syscalltbl script
  s390/syscalls: add system call table
  s390/decompressor: swap .text and .rodata.compressed sections
  s390/sclp: fix .data section specification
  s390/ipl: avoid usage of __section(.data)
  s390/head: replace hard coded values with constants
  s390/disassembler: add generated gen_opcode_table tool to .gitignore
  s390: remove bogus system call table entries
  s390/kprobes: remove duplicate includes
  s390/dasd: Remove dead return code checks
  s390/dasd: Simplify code
  s390/vdso: revise CFI annotations of vDSO functions
  s390/kernel: emit CFI data in .debug_frame and discard .eh_frame sections

2 years agoCoccinelle: coccicheck: fix typo
Julia Lawall [Thu, 1 Feb 2018 09:20:55 +0000 (10:20 +0100)]
Coccinelle: coccicheck: fix typo

Correct spelling of "coccinelle".

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2 years agoMerge branch 'next' into for-linus
Dmitry Torokhov [Thu, 1 Feb 2018 08:37:30 +0000 (00:37 -0800)]
Merge branch 'next' into for-linus

Prepare input updates for 4.16 merge window.

2 years agoMerge tag 'docs-4.16' of git://git.lwn.net/linux
Linus Torvalds [Thu, 1 Feb 2018 03:25:25 +0000 (19:25 -0800)]
Merge tag 'docs-4.16' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "Documentation updates for 4.16.

  New stuff includes refcount_t documentation, errseq documentation,
  kernel-doc support for nested structure definitions, the removal of
  lots of crufty kernel-doc support for unused formats, SPDX tag
  documentation, the beginnings of a manual for subsystem maintainers,
  and lots of fixes and updates.

  As usual, some of the changesets reach outside of Documentation/ to
  effect kerneldoc comment fixes. It also adds the new LICENSES
  directory, of which Thomas promises I do not need to be the
  maintainer"

* tag 'docs-4.16' of git://git.lwn.net/linux: (65 commits)
  linux-next: docs-rst: Fix typos in kfigure.py
  linux-next: DOC: HWPOISON: Fix path to debugfs in hwpoison.txt
  Documentation: Fix misconversion of #if
  docs: add index entry for networking/msg_zerocopy
  Documentation: security/credentials.rst: explain need to sort group_list
  LICENSES: Add MPL-1.1 license
  LICENSES: Add the GPL 1.0 license
  LICENSES: Add Linux syscall note exception
  LICENSES: Add the MIT license
  LICENSES: Add the BSD-3-clause "Clear" license
  LICENSES: Add the BSD 3-clause "New" or "Revised" License
  LICENSES: Add the BSD 2-clause "Simplified" license
  LICENSES: Add the LGPL-2.1 license
  LICENSES: Add the LGPL 2.0 license
  LICENSES: Add the GPL 2.0 license
  Documentation: Add license-rules.rst to describe how to properly identify file licenses
  scripts: kernel_doc: better handle show warnings logic
  fs/*/Kconfig: drop links to 404-compliant http://acl.bestbits.at
  doc: md: Fix a file name to md-fault.c in fault-injection.txt
  errseq: Add to documentation tree
  ...

2 years agoMerge branch 'work.vmci' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Linus Torvalds [Thu, 1 Feb 2018 03:21:14 +0000 (19:21 -0800)]
Merge branch 'work.vmci' of git://git./linux/kernel/git/viro/vfs

Pull vmci iov_iter updates from Al Viro:
 "Get rid of "is it an iovec or an entire array?" flags in vmxi - just
  use iov_iter. Simplifies the living hell out of that code..."

* 'work.vmci' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vmci: the same on the send side...
  vmci: simplify qp_dequeue_locked()
  vmci: get rid of qp_memcpy_from_queue()
  vmci: fix buf_size in case of iovec-based accesses

2 years agoMerge branch 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Thu, 1 Feb 2018 03:18:12 +0000 (19:18 -0800)]
Merge branch 'work.whack-a-mole' of git://git./linux/kernel/git/viro/vfs

Pull asm/uaccess.h whack-a-mole from Al Viro:
 "It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop
  cropping up..."

* 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h
  riscv: use linux/uaccess.h, not asm/uaccess.h...
  ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h

2 years agoMerge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Linus Torvalds [Thu, 1 Feb 2018 03:15:23 +0000 (19:15 -0800)]
Merge branch 'work.dcache' of git://git./linux/kernel/git/viro/vfs

Pull dcache updates from Al Viro:
 "Neil Brown's d_move()/d_path() race fix"

* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  VFS: close race between getcwd() and d_move()

2 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Thu, 1 Feb 2018 02:46:22 +0000 (18:46 -0800)]
Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:

 - misc fixes

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  mm: remove PG_highmem description
  tools, vm: new option to specify kpageflags file
  mm/swap.c: make functions and their kernel-doc agree
  mm, memory_hotplug: fix memmap initialization
  mm: correct comments regarding do_fault_around()
  mm: numa: do not trap faults on shared data section pages.
  hugetlb, mbind: fall back to default policy if vma is NULL
  hugetlb, mempolicy: fix the mbind hugetlb migration
  mm, hugetlb: further simplify hugetlb allocation API
  mm, hugetlb: get rid of surplus page accounting tricks
  mm, hugetlb: do not rely on overcommit limit during migration
  mm, hugetlb: integrate giga hugetlb more naturally to the allocation path
  mm, hugetlb: unify core page allocation accounting and initialization
  mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes
  mm/memcontrol.c: make local symbol static
  mm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd()
  include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer
  mm/compaction.c: fix comment for try_to_compact_pages()
  mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it
  zsmalloc: use U suffix for negative literals being shifted
  ...

2 years agomm: remove PG_highmem description
Miles Chen [Thu, 1 Feb 2018 00:21:27 +0000 (16:21 -0800)]
mm: remove PG_highmem description

Commit cbe37d093707 ("[PATCH] mm: remove PG_highmem") removed PG_highmem
to save a page flag.  So the description of PG_highmem is no longer
needed.

Link: http://lkml.kernel.org/r/1517391212-2950-1-git-send-email-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agotools, vm: new option to specify kpageflags file
David Rientjes [Thu, 1 Feb 2018 00:21:23 +0000 (16:21 -0800)]
tools, vm: new option to specify kpageflags file

page-types currently hardcodes /proc/kpageflags as the file to parse.
This works when using the tool to examine the state of pageflags on the
same system, but does not allow storing a snapshot of pageflags at a
given time to debug issues nor on a different system.

This allows the user to specify a saved version of kpageflags with a new
page-types -F option.

[akpm@linux-foundation.org: add "filename" to fix usage() string]
[rientjes@google.com: fix layout]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1801301840050.140969@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1801301458180.153857@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/swap.c: make functions and their kernel-doc agree
Randy Dunlap [Thu, 1 Feb 2018 00:21:19 +0000 (16:21 -0800)]
mm/swap.c: make functions and their kernel-doc agree

Fix some basic kernel-doc notation in mm/swap.c:

 - for function lru_cache_add_anon(), make its kernel-doc function name
   match its function name and change colon to hyphen following the
   function name

 - for function pagevec_lookup_entries(), change the function parameter
   name from nr_pages to nr_entries since that is more descriptive of
   what the parameter actually is and then it matches the kernel-doc
   comments also

Fix function kernel-doc to match the change in commit 67fd707f4681:

 - drop the kernel-doc notation for @nr_pages from
   pagevec_lookup_range() and correct the function description for that
   change

Link: http://lkml.kernel.org/r/3b42ee3e-04a9-a6ca-6be4-f00752a114fe@infradead.org
Fixes: 67fd707f4681 ("mm: remove nr_pages argument from pagevec_lookup_{,range}_tag()")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, memory_hotplug: fix memmap initialization
Michal Hocko [Thu, 1 Feb 2018 00:21:14 +0000 (16:21 -0800)]
mm, memory_hotplug: fix memmap initialization

Bharata has noticed that onlining a newly added memory doesn't increase
the total memory, pointing to commit f7f99100d8d9 ("mm: stop zeroing
memory during allocation in vmemmap") as a culprit.  This commit has
changed the way how the memory for memmaps is initialized and moves it
from the allocation time to the initialization time.  This works
properly for the early memmap init path.

It doesn't work for the memory hotplug though because we need to mark
page as reserved when the sparsemem section is created and later
initialize it completely during onlining.  memmap_init_zone is called in
the early stage of onlining.  With the current code it calls
__init_single_page and as such it clears up the whole stage and
therefore online_pages_range skips those pages.

Fix this by skipping mm_zero_struct_page in __init_single_page for
memory hotplug path.  This is quite uggly but unifying both early init
and memory hotplug init paths is a large project.  Make sure we plug the
regression at least.

Link: http://lkml.kernel.org/r/20180130101141.GW21609@dhcp22.suse.cz
Fixes: f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Tested-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: correct comments regarding do_fault_around()
William Kucharski [Thu, 1 Feb 2018 00:21:11 +0000 (16:21 -0800)]
mm: correct comments regarding do_fault_around()

There are multiple comments surrounding do_fault_around that memtion
fault_around_pages() and fault_around_mask(), two routines that do not
exist.  These comments should be reworded to reference
fault_around_bytes, the value which is used to determine how much
do_fault_around() will attempt to read when processing a fault.

These comments should have been updated when fault_around_pages() and
fault_around_mask() were removed in commit aecd6f44266c ("mm: close race
between do_fault_around() and fault_around_bytes_set()").

Fixes: aecd6f44266c1 ("mm: close race between do_fault_around() and fault_around_bytes_set()")
Link: http://lkml.kernel.org/r/302D0B14-C7E9-44C6-8BED-033F9ACBD030@oracle.com
Signed-off-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Larry Bassel <larry.bassel@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "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>
2 years agomm: numa: do not trap faults on shared data section pages.
Henry Willard [Thu, 1 Feb 2018 00:21:07 +0000 (16:21 -0800)]
mm: numa: do not trap faults on shared data section pages.

Workloads consisting of a large number of processes running the same
program with a very large shared data segment may experience performance
problems when numa balancing attempts to migrate the shared cow pages.
This manifests itself with many processes or tasks in
TASK_UNINTERRUPTIBLE state waiting for the shared pages to be migrated.

The program listed below simulates the conditions with these results
when run with 288 processes on a 144 core/8 socket machine.

Average throughput  Average throughput     Average throughput
with numa_balancing=0 with numa_balancing=1  with numa_balancing=1
      without the patch      with the patch
--------------------- ---------------------  ---------------------
2118782 2021534        2107979

Complex production environments show less variability and fewer poorly
performing outliers accompanied with a smaller number of processes
waiting on NUMA page migration with this patch applied.  In some cases,
%iowait drops from 16%-26% to 0.

  // SPDX-License-Identifier: GPL-2.0
  /*
   * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
   */
  #include <sys/time.h>
  #include <stdio.h>
  #include <wait.h>
  #include <sys/mman.h>

  int a[1000000] = {13};

  int  main(int argc, const char **argv)
  {
int n = 0;
int i;
pid_t pid;
int stat;
int *count_array;
int cpu_count = 288;
long total = 0;

struct timeval t1, t2 = {(argc > 1 ? atoi(argv[1]) : 10), 0};

if (argc > 2)
cpu_count = atoi(argv[2]);

count_array = mmap(NULL, cpu_count * sizeof(int),
   (PROT_READ|PROT_WRITE),
   (MAP_SHARED|MAP_ANONYMOUS), 0, 0);

if (count_array == MAP_FAILED) {
perror("mmap:");
return 0;
}

for (i = 0; i < cpu_count; ++i) {
pid = fork();
if (pid <= 0)
break;
if ((i & 0xf) == 0)
usleep(2);
}

if (pid != 0) {
if (i == 0) {
perror("fork:");
return 0;
}

for (;;) {
pid = wait(&stat);
if (pid < 0)
break;
}

for (i = 0; i < cpu_count; ++i)
total += count_array[i];

printf("Total %ld\n", total);
munmap(count_array, cpu_count * sizeof(int));
return 0;
}

gettimeofday(&t1, 0);
timeradd(&t1, &t2, &t1);
while (timercmp(&t2, &t1, <)) {
int b = 0;
int j;

for (j = 0; j < 1000000; j++)
b += a[j];
gettimeofday(&t2, 0);
n++;
}
count_array[i] = n;
return 0;
  }

This patch changes change_pte_range() to skip shared copy-on-write pages
when called from change_prot_numa().

NOTE: change_prot_numa() is nominally called from task_numa_work() and
queue_pages_test_walk().  task_numa_work() is the auto NUMA balancing
path, and queue_pages_test_walk() is part of explicit NUMA policy
management.  However, queue_pages_test_walk() only calls
change_prot_numa() when MPOL_MF_LAZY is specified and currently that is
not allowed, so change_prot_numa() is only called from auto NUMA
balancing.

In the case of explicit NUMA policy management, shared pages are not
migrated unless MPOL_MF_MOVE_ALL is specified, and MPOL_MF_MOVE_ALL
depends on CAP_SYS_NICE.  Currently, there is no way to pass information
about MPOL_MF_MOVE_ALL to change_pte_range.  This will have to be fixed
if MPOL_MF_LAZY is enabled and MPOL_MF_MOVE_ALL is to be honored in lazy
migration mode.

task_numa_work() skips the read-only VMAs of programs and shared
libraries.

Link: http://lkml.kernel.org/r/1516751617-7369-1-git-send-email-henry.willard@oracle.com
Signed-off-by: Henry Willard <henry.willard@oracle.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Steve Sistare <steven.sistare@oracle.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agohugetlb, mbind: fall back to default policy if vma is NULL
Michal Hocko [Thu, 1 Feb 2018 00:21:03 +0000 (16:21 -0800)]
hugetlb, mbind: fall back to default policy if vma is NULL

Dan Carpenter has noticed that mbind migration callback (new_page) can
get a NULL vma pointer and choke on it inside alloc_huge_page_vma which
relies on the VMA to get the hstate.  We used to BUG_ON this case but
the BUG_+ON has been removed recently by "hugetlb, mempolicy: fix the
mbind hugetlb migration".

The proper way to handle this is to get the hstate from the migrated
page and rely on huge_node (resp.  get_vma_policy) do the right thing
with null VMA.  We are currently falling back to the default mempolicy
in that case which is in line what THP path is doing here.

Link: http://lkml.kernel.org/r/20180110104712.GR1732@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agohugetlb, mempolicy: fix the mbind hugetlb migration
Michal Hocko [Thu, 1 Feb 2018 00:21:00 +0000 (16:21 -0800)]
hugetlb, mempolicy: fix the mbind hugetlb migration

do_mbind migration code relies on alloc_huge_page_noerr for hugetlb
pages.  alloc_huge_page_noerr uses alloc_huge_page which is a highlevel
allocation function which has to take care of reserves, overcommit or
hugetlb cgroup accounting.  None of that is really required for the page
migration because the new page is only temporal and either will replace
the original page or it will be dropped.  This is essentially as for
other migration call paths and there shouldn't be any reason to handle
mbind in a special way.

The current implementation is even suboptimal because the migration
might fail just because the hugetlb cgroup limit is reached, or the
overcommit is saturated.

Fix this by making mbind like other hugetlb migration paths.  Add a new
migration helper alloc_huge_page_vma as a wrapper around
alloc_huge_page_nodemask with additional mempolicy handling.

alloc_huge_page_noerr has no more users and it can go.

Link: http://lkml.kernel.org/r/20180103093213.26329-7-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Reale <ar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, hugetlb: further simplify hugetlb allocation API
Michal Hocko [Thu, 1 Feb 2018 00:20:56 +0000 (16:20 -0800)]
mm, hugetlb: further simplify hugetlb allocation API

Hugetlb allocator has several layer of allocation functions depending
and the purpose of the allocation.  There are two allocators depending
on whether the page can be allocated from the page allocator or we need
a contiguous allocator.  This is currently opencoded in
alloc_fresh_huge_page which is the only path that might allocate giga
pages which require the later allocator.  Create alloc_fresh_huge_page
which hides this implementation detail and use it in all callers which
hardcoded the buddy allocator path (__hugetlb_alloc_buddy_huge_page).
This shouldn't introduce any funtional change because both migration and
surplus allocators exlude giga pages explicitly.

While we are at it let's do some renaming.  The current scheme is not
consistent and overly painfull to read and understand.  Get rid of
prefix underscores from most functions.  There is no real reason to make
names longer.

* alloc_fresh_huge_page is the new layer to abstract underlying
  allocator
* __hugetlb_alloc_buddy_huge_page becomes shorter and neater
  alloc_buddy_huge_page.
* Former alloc_fresh_huge_page becomes alloc_pool_huge_page because we put
  the new page directly to the pool
* alloc_surplus_huge_page can drop the opencoded prep_new_huge_page code
  as it uses alloc_fresh_huge_page now
* others lose their excessive prefix underscores to make names shorter

[dan.carpenter@oracle.com: fix double unlock bug in alloc_surplus_huge_page()]
Link: http://lkml.kernel.org/r/20180109200559.g3iz5kvbdrz7yydp@mwanda
Link: http://lkml.kernel.org/r/20180103093213.26329-6-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Reale <ar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, hugetlb: get rid of surplus page accounting tricks
Michal Hocko [Thu, 1 Feb 2018 00:20:52 +0000 (16:20 -0800)]
mm, hugetlb: get rid of surplus page accounting tricks

alloc_surplus_huge_page increases the pool size and the number of
surplus pages opportunistically to prevent from races with the pool size
change.  See commit d1c3fb1f8f29 ("hugetlb: introduce
nr_overcommit_hugepages sysctl") for more details.

The resulting code is unnecessarily hairy, cause code duplication and
doesn't allow to share the allocation paths.  Moreover pool size changes
tend to be very seldom so optimizing for them is not really reasonable.
Simplify the code and allow to allocate a fresh surplus page as long as
we are under the overcommit limit and then recheck the condition after
the allocation and drop the new page if the situation has changed.  This
should provide a reasonable guarantee that an abrupt allocation requests
will not go way off the limit.

If we consider races with the pool shrinking and enlarging then we
should be reasonably safe as well.  In the first case we are off by one
in the worst case and the second case should work OK because the page is
not yet visible.  We can waste CPU cycles for the allocation but that
should be acceptable for a relatively rare condition.

Link: http://lkml.kernel.org/r/20180103093213.26329-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Reale <ar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, hugetlb: do not rely on overcommit limit during migration
Michal Hocko [Thu, 1 Feb 2018 00:20:48 +0000 (16:20 -0800)]
mm, hugetlb: do not rely on overcommit limit during migration

hugepage migration relies on __alloc_buddy_huge_page to get a new page.
This has 2 main disadvantages.

1) it doesn't allow to migrate any huge page if the pool is used
   completely which is not an exceptional case as the pool is static and
   unused memory is just wasted.

2) it leads to a weird semantic when migration between two numa nodes
   might increase the pool size of the destination NUMA node while the
   page is in use.  The issue is caused by per NUMA node surplus pages
   tracking (see free_huge_page).

Address both issues by changing the way how we allocate and account
pages allocated for migration.  Those should temporal by definition.  So
we mark them that way (we will abuse page flags in the 3rd page) and
update free_huge_page to free such pages to the page allocator.  Page
migration path then just transfers the temporal status from the new page
to the old one which will be freed on the last reference.  The global
surplus count will never change during this path but we still have to be
careful when migrating a per-node suprlus page.  This is now handled in
move_hugetlb_state which is called from the migration path and it copies
the hugetlb specific page state and fixes up the accounting when needed

Rename __alloc_buddy_huge_page to __alloc_surplus_huge_page to better
reflect its purpose.  The new allocation routine for the migration path
is __alloc_migrate_huge_page.

The user visible effect of this patch is that migrated pages are really
temporal and they travel between NUMA nodes as per the migration
request:

Before migration
  /sys/devices/system/node/node0/hugepages/hugepages-2048kB/free_hugepages:0
  /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:1
  /sys/devices/system/node/node0/hugepages/hugepages-2048kB/surplus_hugepages:0
  /sys/devices/system/node/node1/hugepages/hugepages-2048kB/free_hugepages:0
  /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:0
  /sys/devices/system/node/node1/hugepages/hugepages-2048kB/surplus_hugepages:0

After
  /sys/devices/system/node/node0/hugepages/hugepages-2048kB/free_hugepages:0
  /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:0
  /sys/devices/system/node/node0/hugepages/hugepages-2048kB/surplus_hugepages:0
  /sys/devices/system/node/node1/hugepages/hugepages-2048kB/free_hugepages:0
  /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:1
  /sys/devices/system/node/node1/hugepages/hugepages-2048kB/surplus_hugepages:0

with the previous implementation, both nodes would have nr_hugepages:1
until the page is freed.

Link: http://lkml.kernel.org/r/20180103093213.26329-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Reale <ar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, hugetlb: integrate giga hugetlb more naturally to the allocation path
Michal Hocko [Thu, 1 Feb 2018 00:20:44 +0000 (16:20 -0800)]
mm, hugetlb: integrate giga hugetlb more naturally to the allocation path

Gigantic hugetlb pages were ingrown to the hugetlb code as an alien
specie with a lot of special casing.  The allocation path is not an
exception.  Unnecessarily so to be honest.  It is true that the
underlying allocator is different but that is an implementation detail.

This patch unifies the hugetlb allocation path that a prepares fresh
pool pages.  alloc_fresh_gigantic_page basically copies
alloc_fresh_huge_page logic so we can move everything there.  This will
simplify set_max_huge_pages which doesn't have to care about what kind
of huge page we allocate.

Link: http://lkml.kernel.org/r/20180103093213.26329-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Reale <ar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, hugetlb: unify core page allocation accounting and initialization
Michal Hocko [Thu, 1 Feb 2018 00:20:41 +0000 (16:20 -0800)]
mm, hugetlb: unify core page allocation accounting and initialization

Patch series "mm, hugetlb: allocation API and migration improvements"

Motivation:

this is a follow up for [3] for the allocation API and [4] for the
hugetlb migration.  It wasn't really easy to split those into two
separate patch series as they share some code.

My primary motivation to touch this code is to make the gigantic pages
migration working.  The giga pages allocation code is just too fragile
and hacked into the hugetlb code now.  This series tries to move giga
pages closer to the first class citizen.  We are not there yet but
having 5 patches is quite a lot already and it will already make the
code much easier to follow.  I will come with other changes on top after
this sees some review.

The first two patches should be trivial to review.  The third patch
changes the way how we migrate huge pages.  Newly allocated pages are a
subject of the overcommit check and they participate surplus accounting
which is quite unfortunate as the changelog explains.  This patch
doesn't change anything wrt.  giga pages.

Patch #4 removes the surplus accounting hack from
__alloc_surplus_huge_page.  I hope I didn't miss anything there and a
deeper review is really due there.

Patch #5 finally unifies allocation paths and giga pages shouldn't be
any special anymore.  There is also some renaming going on as well.

This patch (of 6):

hugetlb allocator has two entry points to the page allocator
 - alloc_fresh_huge_page_node
 - __hugetlb_alloc_buddy_huge_page

The two differ very subtly in two aspects.  The first one doesn't care
about HTLB_BUDDY_* stats and it doesn't initialize the huge page.
prep_new_huge_page is not used because it not only initializes hugetlb
specific stuff but because it also put_page and releases the page to the
hugetlb pool which is not what is required in some contexts.  This makes
things more complicated than necessary.

Simplify things by a) removing the page allocator entry point duplicity
and only keep __hugetlb_alloc_buddy_huge_page and b) make
prep_new_huge_page more reusable by removing the put_page which moves
the page to the allocator pool.  All current callers are updated to call
put_page explicitly.  Later patches will add new callers which won't
need it.

This patch shouldn't introduce any functional change.

Link: http://lkml.kernel.org/r/20180103093213.26329-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrea Reale <ar@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes
Andrey Ryabinin [Thu, 1 Feb 2018 00:20:37 +0000 (16:20 -0800)]
mm/memcontrol.c: try harder to decrease [memory,memsw].limit_in_bytes

mem_cgroup_resize_[memsw]_limit() tries to free only 32
(SWAP_CLUSTER_MAX) pages on each iteration.  This makes it practically
impossible to decrease limit of memory cgroup.  Tasks could easily
allocate back 32 pages, so we can't reduce memory usage, and once
retry_count reaches zero we return -EBUSY.

Easy to reproduce the problem by running the following commands:

  mkdir /sys/fs/cgroup/memory/test
  echo $$ >> /sys/fs/cgroup/memory/test/tasks
  cat big_file > /dev/null &
  sleep 1 && echo $((100*1024*1024)) > /sys/fs/cgroup/memory/test/memory.limit_in_bytes
  -bash: echo: write error: Device or resource busy

Instead of relying on retry_count, keep retrying the reclaim until the
desired limit is reached or fail if the reclaim doesn't make any
progress or a signal is pending.

Link: http://lkml.kernel.org/r/20180119132544.19569-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/memcontrol.c: make local symbol static
Christopher Díaz Riveros [Thu, 1 Feb 2018 00:20:33 +0000 (16:20 -0800)]
mm/memcontrol.c: make local symbol static

Fix the following sparse warning:

  mm/memcontrol.c:1097:14: warning: symbol 'memcg1_stats' was not declared. Should it be static?

Link: http://lkml.kernel.org/r/20180118193327.14200-1-chrisadr@gentoo.org
Signed-off-by: Christopher Díaz Riveros <chrisadr@gentoo.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd()
Ralph Campbell [Thu, 1 Feb 2018 00:20:30 +0000 (16:20 -0800)]
mm/hmm: fix uninitialized use of 'entry' in hmm_vma_walk_pmd()

The variable 'entry' is used before being initialized in
hmm_vma_walk_pmd().

No bad effect (beside performance hit) so !non_swap_entry(0) evaluate to
true which trigger a fault as if CPU was trying to access migrated
memory and migrate memory back from device memory to regular memory.

This function (hmm_vma_walk_pmd()) is called when a device driver tries
to populate its own page table.  For migrated memory it should not
happen as the device driver should already have populated its page table
correctly during the migration.

Only case I can think of is multi-GPU where a second GPU triggers
migration back to regular memory.  Again this would just result in a
performance hit, nothing bad would happen.

Link: http://lkml.kernel.org/r/20180122185759.26286-1-jglisse@redhat.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoinclude/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer
Petr Tesarik [Thu, 1 Feb 2018 00:20:26 +0000 (16:20 -0800)]
include/linux/mmzone.h: fix explanation of lower bits in the SPARSEMEM mem_map pointer

The comment is confusing.  On the one hand, it refers to 32-bit
alignment (struct page alignment on 32-bit platforms), but this would
only guarantee that the 2 lowest bits must be zero.  On the other hand,
it claims that at least 3 bits are available, and 3 bits are actually
used.

This is not broken, because there is a stronger alignment guarantee,
just less obvious.  Let's fix the comment to make it clear how many bits
are available and why.

Although memmap arrays are allocated in various places, the resulting
pointer is encoded eventually, so I am adding a BUG_ON() here to enforce
at runtime that all expected bits are indeed available.

I have also added a BUILD_BUG_ON to check that PFN_SECTION_SHIFT is
sufficient, because this part of the calculation can be easily checked
at build time.

[ptesarik@suse.com: v2]
Link: http://lkml.kernel.org/r/20180125100516.589ea6af@ezekiel.suse.cz
Link: http://lkml.kernel.org/r/20180119080908.3a662e6f@ezekiel.suse.cz
Signed-off-by: Petr Tesarik <ptesarik@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/compaction.c: fix comment for try_to_compact_pages()
Yang Shi [Thu, 1 Feb 2018 00:20:23 +0000 (16:20 -0800)]
mm/compaction.c: fix comment for try_to_compact_pages()

"mode" argument is not used by try_to_compact_pages() and sub functions
anymore, it has been replaced by "prio".  Fix the comment to explain the
use of "prio" argument.

Link: http://lkml.kernel.org/r/1515801336-20611-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it
Oscar Salvador [Thu, 1 Feb 2018 00:20:19 +0000 (16:20 -0800)]
mm/page_ext.c: make page_ext_init a noop when CONFIG_PAGE_EXTENSION but nothing uses it

static struct page_ext_operations *page_ext_ops[] always contains debug_guardpage_ops,

static struct page_ext_operations *page_ext_ops[] = {
        &debug_guardpage_ops,
 #ifdef CONFIG_PAGE_OWNER
        &page_owner_ops,
 #endif
...
}

but for it to work, CONFIG_DEBUG_PAGEALLOC must be enabled first.  If
someone has CONFIG_PAGE_EXTENSION, but has none of its users, eg:
(CONFIG_PAGE_OWNER, CONFIG_DEBUG_PAGEALLOC, CONFIG_IDLE_PAGE_TRACKING),
we can shrink page_ext_init() to a simple retq.

  $ size vmlinux  (before patch)
        text      data       bss       dec       hex  filename
    14356698   5681582   1687748  21726028   14b834c  vmlinux

  $ size vmlinux  (after patch)
        text      data       bss       dec       hex  filename
    14356008   5681538   1687748  21725294   14b806e  vmlinux

On the other hand, it might does not even make sense, since if someone
enables CONFIG_PAGE_EXTENSION, I would expect him to enable also at
least one of its users.

Link: http://lkml.kernel.org/r/20180105130235.GA21241@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@techadventures.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jaewon Kim <jaewon31.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agozsmalloc: use U suffix for negative literals being shifted
Nick Desaulniers [Thu, 1 Feb 2018 00:20:15 +0000 (16:20 -0800)]
zsmalloc: use U suffix for negative literals being shifted

Fix warning about shifting unsigned literals being undefined behavior.

Link: http://lkml.kernel.org/r/1515642078-4259-1-git-send-email-nick.desaulniers@gmail.com
Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nick Desaulniers <nick.desaulniers@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/page_owner.c: clean up init_pages_in_zone()
Oscar Salvador [Thu, 1 Feb 2018 00:20:11 +0000 (16:20 -0800)]
mm/page_owner.c: clean up init_pages_in_zone()

Remove two redundant assignments in init_pages_in_zone().

[osalvador@techadventures.net: v3]
Link: http://lkml.kernel.org/r/20180117124513.GA876@techadventures.net
[akpm@linux-foundation.org: coding style tweaks]
Link: http://lkml.kernel.org/r/20180110084355.GA22822@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@techadventures.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
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>
2 years agomm/page_alloc.c: fix typos in comments
Shile Zhang [Thu, 1 Feb 2018 00:20:07 +0000 (16:20 -0800)]
mm/page_alloc.c: fix typos in comments

Link: http://lkml.kernel.org/r/1515485774-4768-1-git-send-email-zhangshile@gmail.com
Signed-off-by: Shile Zhang <zhangshile@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomemcg: refactor mem_cgroup_resize_limit()
Yu Zhao [Thu, 1 Feb 2018 00:20:02 +0000 (16:20 -0800)]
memcg: refactor mem_cgroup_resize_limit()

mem_cgroup_resize_limit() and mem_cgroup_resize_memsw_limit() have
identical logics.  Refactor code so we don't need to keep two pieces of
code that does same thing.

Link: http://lkml.kernel.org/r/20180108224238.14583-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agozswap: only save zswap header when necessary
Yu Zhao [Thu, 1 Feb 2018 00:19:59 +0000 (16:19 -0800)]
zswap: only save zswap header when necessary

We waste sizeof(swp_entry_t) for zswap header when using zsmalloc as
zpool driver because zsmalloc doesn't support eviction.

Add zpool_evictable() to detect if zpool is potentially evictable, and
use it in zswap to avoid waste memory for zswap header.

[yuzhao@google.com: The zpool->" prefix is a result of copy & paste]
Link: http://lkml.kernel.org/r/20180110225626.110330-1-yuzhao@google.com
Link: http://lkml.kernel.org/r/20180110224741.83751-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Dan Streetman <ddstreet@ieee.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/fadvise: discard partial page if endbyte is also EOF
shidao.ytt [Thu, 1 Feb 2018 00:19:55 +0000 (16:19 -0800)]
mm/fadvise: discard partial page if endbyte is also EOF

During our recent testing with fadvise(FADV_DONTNEED), we find that if
given offset/length is not page-aligned, the last page will not be
discarded.  The tool we use is vmtouch (https://hoytech.com/vmtouch/),
we map a 10KB-sized file into memory and then try to run this tool to
evict the whole file mapping, but the last single page always remains
staying in the memory:

$./vmtouch -e test_10K
           Files: 1
     Directories: 0
   Evicted Pages: 3 (12K)
         Elapsed: 2.1e-05 seconds

$./vmtouch test_10K
           Files: 1
     Directories: 0
  Resident Pages: 1/3  4K/12K  33.3%
         Elapsed: 5.5e-05 seconds

However when we test with an older kernel, say 3.10, this problem is
gone.  So we wonder if this is a regression:

$./vmtouch -e test_10K
           Files: 1
     Directories: 0
   Evicted Pages: 3 (12K)
         Elapsed: 8.2e-05 seconds

$./vmtouch test_10K
           Files: 1
     Directories: 0
  Resident Pages: 0/3  0/12K  0%  <-- partial page also discarded
         Elapsed: 5e-05 seconds

After digging a little bit into this problem, we find it seems not a
regression.  Not discarding partial page is likely to be on purpose
according to commit 441c228f817f ("mm: fadvise: document the
fadvise(FADV_DONTNEED) behaviour for partial pages") written by Mel
Gorman.  He explained why partial pages should be preserved instead of
being discarded when using fadvise(FADV_DONTNEED).

However, the interesting part is that the actual code did NOT work as
the same as it was described, the partial page was still discarded
anyway, due to a calculation mistake of `end_index' passed to
invalidate_mapping_pages().  This mistake has not been fixed until
recently, that's why we fail to reproduce our problem in old kernels.
The fix is done in commit 18aba41cbf ("mm/fadvise.c: do not discard
partial pages with POSIX_FADV_DONTNEED") by Oleg Drokin.

Back to the original testing, our problem becomes that there is a
special case that, if the page-unaligned `endbyte' is also the end of
file, it is not necessary at all to preserve the last partial page, as
we all know no one else will use the rest of it.  It should be safe
enough if we just discard the whole page.  So we add an EOF check in
this patch.

We also find a poosbile real world issue in mainline kernel.  Assume
such scenario: A userspace backup application want to backup a huge
amount of small files (<4k) at once, the developer might (I guess) want
to use fadvise(FADV_DONTNEED) to save memory.  However, FADV_DONTNEED
won't really happen since the only page mapped is a partial page, and
kernel will preserve it.  Our patch also fixes this problem, since we
know the endbyte is EOF, so we discard it.

Here is a simple reproducer to reproduce and verify each scenario we
described above:

  test_fadvise.c
  ==============================
  #include <sys/mman.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <stdlib.h>
  #include <string.h>
  #include <stdio.h>
  #include <unistd.h>

  int main(int argc, char **argv)
  {
   int i, fd, ret, len;
   struct stat buf;
   void *addr;
   unsigned char *vec;
   char *strbuf;
   ssize_t pagesize = getpagesize();
   ssize_t filesize;

   fd = open(argv[1], O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
   if (fd < 0)
   return -1;
   filesize = strtoul(argv[2], NULL, 10);

   strbuf = malloc(filesize);
   memset(strbuf, 42, filesize);
   write(fd, strbuf, filesize);
   free(strbuf);
   fsync(fd);

   len = (filesize + pagesize - 1) / pagesize;
   printf("length of pages: %d\n", len);

   addr = mmap(NULL, filesize, PROT_READ, MAP_SHARED, fd, 0);
   if (addr == MAP_FAILED)
   return -1;

   ret = posix_fadvise(fd, 0, filesize, POSIX_FADV_DONTNEED);
   if (ret < 0)
   return -1;

   vec = malloc(len);
   ret = mincore(addr, filesize, (void *)vec);
   if (ret < 0)
   return -1;

   for (i = 0; i < len; i++)
   printf("pages[%d]: %x\n", i, vec[i] & 0x1);

   free(vec);
   close(fd);

   return 0;
  }
  ==============================

Test 1: running on kernel with commit 18aba41cbf reverted:

  [root@caspar ~]# uname -r
  4.15.0-rc6.revert+
  [root@caspar ~]# ./test_fadvise file1 1024
  length of pages: 1
  pages[0]: 0    # <-- partial page discarded
  [root@caspar ~]# ./test_fadvise file2 8192
  length of pages: 2
  pages[0]: 0
  pages[1]: 0
  [root@caspar ~]# ./test_fadvise file3 10240
  length of pages: 3
  pages[0]: 0
  pages[1]: 0
  pages[2]: 0    # <-- partial page discarded

Test 2: running on mainline kernel:

  [root@caspar ~]# uname -r
  4.15.0-rc6+
  [root@caspar ~]# ./test_fadvise test1 1024
  length of pages: 1
  pages[0]: 1    # <-- partial and the only page not discarded
  [root@caspar ~]# ./test_fadvise test2 8192
  length of pages: 2
  pages[0]: 0
  pages[1]: 0
  [root@caspar ~]# ./test_fadvise test3 10240
  length of pages: 3
  pages[0]: 0
  pages[1]: 0
  pages[2]: 1    # <-- partial page not discarded

Test 3: running on kernel with this patch:

  [root@caspar ~]# uname -r
  4.15.0-rc6.patched+
  [root@caspar ~]# ./test_fadvise test1 1024
  length of pages: 1
  pages[0]: 0    # <-- partial page and EOF, discarded
  [root@caspar ~]# ./test_fadvise test2 8192
  length of pages: 2
  pages[0]: 0
  pages[1]: 0
  [root@caspar ~]# ./test_fadvise test3 10240
  length of pages: 3
  pages[0]: 0
  pages[1]: 0
  pages[2]: 0    # <-- partial page and EOF, discarded

[akpm@linux-foundation.org: tweak code comment]
Link: http://lkml.kernel.org/r/5222da9ee20e1695eaabb69f631f200d6e6b8876.1515132470.git.jinli.zjl@alibaba-inc.com
Signed-off-by: shidao.ytt <shidao.ytt@alibaba-inc.com>
Signed-off-by: Caspar Zhang <jinli.zjl@alibaba-inc.com>
Reviewed-by: Oliver Yang <zhiche.yy@alibaba-inc.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>
2 years agomm: pin address_space before dereferencing it while isolating an LRU page
Mel Gorman [Thu, 1 Feb 2018 00:19:52 +0000 (16:19 -0800)]
mm: pin address_space before dereferencing it while isolating an LRU page

Minchan Kim asked the following question -- what locks protects
address_space destroying when race happens between inode trauncation and
__isolate_lru_page? Jan Kara clarified by describing the race as follows

CPU1                                            CPU2

truncate(inode)                                 __isolate_lru_page()
  ...
  truncate_inode_page(mapping, page);
    delete_from_page_cache(page)
      spin_lock_irqsave(&mapping->tree_lock, flags);
        __delete_from_page_cache(page, NULL)
          page_cache_tree_delete(..)
            ...                                   mapping = page_mapping(page);
            page->mapping = NULL;
            ...
      spin_unlock_irqrestore(&mapping->tree_lock, flags);
      page_cache_free_page(mapping, page)
        put_page(page)
          if (put_page_testzero(page)) -> false
- inode now has no pages and can be freed including embedded address_space

                                                  if (mapping && !mapping->a_ops->migratepage)
- we've dereferenced mapping which is potentially already free.

The race is theoretically possible but unlikely.  Before the
delete_from_page_cache, truncate_cleanup_page is called so the page is
likely to be !PageDirty or PageWriteback which gets skipped by the only
caller that checks the mappping in __isolate_lru_page.  Even if the race
occurs, a substantial amount of work has to happen during a tiny window
with no preemption but it could potentially be done using a virtual
machine to artifically slow one CPU or halt it during the critical
window.

This patch should eliminate the race with truncation by try-locking the
page before derefencing mapping and aborting if the lock was not
acquired.  There was a suggestion from Huang Ying to use RCU as a
side-effect to prevent mapping being freed.  However, I do not like the
solution as it's an unconventional means of preserving a mapping and
it's not a context where rcu_read_lock is obviously protecting rcu data.

Link: http://lkml.kernel.org/r/20180104102512.2qos3h5vqzeisrek@techsingularity.net
Fixes: c82449352854 ("mm: compaction: make isolate_lru_page() filter-aware again")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agouserfaultfd: convert to use anon_inode_getfd()
Eric Biggers [Thu, 1 Feb 2018 00:19:48 +0000 (16:19 -0800)]
userfaultfd: convert to use anon_inode_getfd()

Nothing actually calls userfaultfd_file_create() besides the
userfaultfd() system call itself.  So simplify things by folding it into
the system call and using anon_inode_getfd() instead of
anon_inode_getfile().  Do the same in resolve_userfault_fork() as well.

This removes over 50 lines with no change in functionality.

Link: http://lkml.kernel.org/r/20171229212403.22800-1-ebiggers3@gmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomemfd-test: run fuse test on hugetlb backend memory
Marc-André Lureau [Thu, 1 Feb 2018 00:19:44 +0000 (16:19 -0800)]
memfd-test: run fuse test on hugetlb backend memory

Link: http://lkml.kernel.org/r/20171107122800.25517-10-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomemfd-test: move common code to a shared unit
Marc-André Lureau [Thu, 1 Feb 2018 00:19:40 +0000 (16:19 -0800)]
memfd-test: move common code to a shared unit

The memfd & fuse tests will share more common code in the following
commits to test hugetlb support.

Link: http://lkml.kernel.org/r/20171107122800.25517-9-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomemfd-test: add 'memfd-hugetlb:' prefix when testing hugetlbfs
Marc-André Lureau [Thu, 1 Feb 2018 00:19:36 +0000 (16:19 -0800)]
memfd-test: add 'memfd-hugetlb:' prefix when testing hugetlbfs

Link: http://lkml.kernel.org/r/20171107122800.25517-8-marcandre.lureau@redhat.com
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomemfd-test: test hugetlbfs sealing
Marc-André Lureau [Thu, 1 Feb 2018 00:19:32 +0000 (16:19 -0800)]
memfd-test: test hugetlbfs sealing

Remove most of the special-casing of hugetlbfs now that sealing is
supported.

Link: http://lkml.kernel.org/r/20171107122800.25517-7-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoshmem: add sealing support to hugetlb-backed memfd
Marc-André Lureau [Thu, 1 Feb 2018 00:19:29 +0000 (16:19 -0800)]
shmem: add sealing support to hugetlb-backed memfd

Adapt add_seals()/get_seals() to work with hugetbfs-backed memory.

Teach memfd_create() to allow sealing operations on MFD_HUGETLB.

Link: http://lkml.kernel.org/r/20171107122800.25517-6-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agohugetlb: implement memfd sealing
Marc-André Lureau [Thu, 1 Feb 2018 00:19:25 +0000 (16:19 -0800)]
hugetlb: implement memfd sealing

Implements memfd sealing, similar to shmem:
 - WRITE: deny fallocate(PUNCH_HOLE). mmap() write is denied in
   memfd_add_seals(). write() doesn't exist for hugetlbfs.
 - SHRINK: added similar check as shmem_setattr()
 - GROW: added similar check as shmem_setattr() & shmem_fallocate()

Except write() operation that doesn't exist with hugetlbfs, that should
make sealing as close as it can be to shmem support.

Link: http://lkml.kernel.org/r/20171107122800.25517-5-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agohugetlb: expose hugetlbfs_inode_info in header
Marc-André Lureau [Thu, 1 Feb 2018 00:19:22 +0000 (16:19 -0800)]
hugetlb: expose hugetlbfs_inode_info in header

hugetlbfs inode information will need to be accessed by code in
mm/shmem.c for file sealing operations.  Move inode information
definition from .c file to header for needed access.

Link: http://lkml.kernel.org/r/20171107122800.25517-4-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoshmem: rename functions that are memfd-related
Marc-André Lureau [Thu, 1 Feb 2018 00:19:18 +0000 (16:19 -0800)]
shmem: rename functions that are memfd-related

Those functions are called for memfd files, backed by shmem or hugetlb
(the next patches will handle hugetlb).

Link: http://lkml.kernel.org/r/20171107122800.25517-3-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoshmem: unexport shmem_add_seals()/shmem_get_seals()
Marc-André Lureau [Thu, 1 Feb 2018 00:19:14 +0000 (16:19 -0800)]
shmem: unexport shmem_add_seals()/shmem_get_seals()

Patch series "memfd: add sealing to hugetlb-backed memory", v3.

Recently, Mike Kravetz added hugetlbfs support to memfd.  However, he
didn't add sealing support.  One of the reasons to use memfd is to have
shared memory sealing when doing IPC or sharing memory with another
process with some extra safety.  qemu uses shared memory & hugetables
with vhost-user (used by dpdk), so it is reasonable to use memfd now
instead for convenience and security reasons.

This patch (of 9):

The functions are called through shmem_fcntl() only.  And no danger in
removing the EXPORTs as the routines only work with shmem file structs.

Link: http://lkml.kernel.org/r/20171107122800.25517-2-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: remove reference to PG_buddy
Matthew Wilcox [Thu, 1 Feb 2018 00:19:11 +0000 (16:19 -0800)]
mm: remove reference to PG_buddy

PG_buddy doesn't exist any more.  It's called PageBuddy now.

Link: http://lkml.kernel.org/r/20171220155552.15884-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: document how to use struct page
Matthew Wilcox [Thu, 1 Feb 2018 00:19:06 +0000 (16:19 -0800)]
mm: document how to use struct page

Be really explicit about what bits / bytes are reserved for users that
want to store extra information about the pages they allocate.

Link: http://lkml.kernel.org/r/20171220155552.15884-8-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: store compound_dtor / compound_order as bytes
Matthew Wilcox [Thu, 1 Feb 2018 00:19:02 +0000 (16:19 -0800)]
mm: store compound_dtor / compound_order as bytes

Neither of these values get even close to 256; compound_dtor is
currently at a maximum of 3, and compound_order can't be over 64.  No
machine has inefficient access to bytes since EV5, and while those are
still supported, we don't optimise for them any more.  This does not
shrink struct page, but it removes an ifdef and frees up 2-6 bytes for
future use.

diff of pahole output:

  struct callback_head callback_head;      /*    32    16 */
  struct {
  long unsigned int compound_head; /*    32     8 */
- unsigned int compound_dtor;      /*    40     4 */
- unsigned int compound_order;     /*    44     4 */
+ unsigned char compound_dtor;     /*    40     1 */
+ unsigned char compound_order;    /*    41     1 */
  };                                       /*    32    16 */
  };                                               /*    32    16 */
  union {

[mawilcox@microsoft.com: add comment]
Link: http://lkml.kernel.org/r/20171221000144.GB2980@bombadil.infradead.org
Link: http://lkml.kernel.org/r/20171220155552.15884-7-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: introduce _slub_counter_t
Matthew Wilcox [Thu, 1 Feb 2018 00:18:58 +0000 (16:18 -0800)]
mm: introduce _slub_counter_t

Instead of putting the ifdef in the middle of the definition of struct
page, pull it forward to the rest of the ifdeffery around the SLUB
cmpxchg_double optimisation.

Link: http://lkml.kernel.org/r/20171220155552.15884-6-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: improve comment on page->mapping
Matthew Wilcox [Thu, 1 Feb 2018 00:18:55 +0000 (16:18 -0800)]
mm: improve comment on page->mapping

The comment on page->mapping is terse, and out of date (it does not
mention the possibility of PAGE_MAPPING_MOVABLE).  Instead, point the
interested reader to page-flags.h where there is a much better comment.

Link: http://lkml.kernel.org/r/20171220155552.15884-5-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: remove misleading alignment claims
Matthew Wilcox [Thu, 1 Feb 2018 00:18:51 +0000 (16:18 -0800)]
mm: remove misleading alignment claims

The "third double word block" isn't on 32-bit systems.  The layout looks
like this:

unsigned long flags;
struct address_space *mapping
pgoff_t index;
atomic_t _mapcount;
atomic_t _refcount;

which is 32 bytes on 64-bit, but 20 bytes on 32-bit.  Nobody is trying to
use the fact that it's double-word aligned today, so just remove the
misleading claims.

Link: http://lkml.kernel.org/r/20171220155552.15884-4-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: de-indent struct page
Matthew Wilcox [Thu, 1 Feb 2018 00:18:47 +0000 (16:18 -0800)]
mm: de-indent struct page

I found the struct { union { struct { union { struct { } } } } } layout
rather confusing.  Fortunately, there is an easier way to write this.

The innermost union is of four things which are the size of an int, so
the ones which are used by slab/slob/slub can be pulled up two levels to
be in the outermost union with 'counters'.  That leaves us with struct {
union { struct { atomic_t; atomic_t; } } } which has the same layout,
but is easier to read.

Output from the current git version of pahole, diffed with -uw to ignore
the whitespace changes from the indentation:

  }; /*    16     8 */
  union {
  long unsigned int  counters; /*    24     8 */
- struct {
- union {
- atomic_t _mapcount; /*    24     4 */
  unsigned int active; /*    24     4 */
  struct {
  unsigned int inuse:16; /*    24:16  4 */
@@ -21,7 +18,8 @@
  unsigned int frozen:1; /*    24: 0  4 */
  }; /*    24     4 */
  int units; /*    24     4 */
- }; /*    24     4 */
+ struct {
+ atomic_t   _mapcount; /*    24     4 */
  atomic_t   _refcount; /*    28     4 */
  }; /*    24     8 */
  }; /*    24     8 */

Link: http://lkml.kernel.org/r/20171220155552.15884-3-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: align struct page more aesthetically
Matthew Wilcox [Thu, 1 Feb 2018 00:18:44 +0000 (16:18 -0800)]
mm: align struct page more aesthetically

Patch series "Restructure struct page", v2.

This series does not attempt any grand restructuring.  Instead, it cures
the worst of the indentitis, fixes the documentation and reduces the
ifdeffery.  The only layout change is compound_dtor and compound_order
are each reduced to one byte.

This patch (of 8):

Instead of an ifdef block at the end of the struct, which needed its own
comment, define _struct_page_alignment up at the top where it fits
nicely with the existing comment.

Link: http://lkml.kernel.org/r/20171220155552.15884-2-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/zsmalloc: simplify shrinker init/destroy
Aliaksei Karaliou [Thu, 1 Feb 2018 00:18:40 +0000 (16:18 -0800)]
mm/zsmalloc: simplify shrinker init/destroy

Structure zs_pool has special flag to indicate success of shrinker
initialization.  unregister_shrinker() has improved and can detect by
itself whether actual deinitialization should be performed or not, so
extra flag becomes redundant.

[akpm@linux-foundation.org: update comment (Aliaksei), remove unneeded cast]
Link: http://lkml.kernel.org/r/1513680552-9798-1-git-send-email-akaraliou.dev@gmail.com
Signed-off-by: Aliaksei Karaliou <akaraliou.dev@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, oom: avoid reaping only for mm's with blockable invalidate callbacks
David Rientjes [Thu, 1 Feb 2018 00:18:36 +0000 (16:18 -0800)]
mm, oom: avoid reaping only for mm's with blockable invalidate callbacks

This uses the new annotation to determine if an mm has mmu notifiers
with blockable invalidate range callbacks to avoid oom reaping.
Otherwise, the callbacks are used around unmap_page_range().

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1712141330120.74052@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dimitri Sivanich <sivanich@hpe.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks
David Rientjes [Thu, 1 Feb 2018 00:18:32 +0000 (16:18 -0800)]
mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks

Commit 4d4bbd8526a8 ("mm, oom_reaper: skip mm structs with mmu
notifiers") prevented the oom reaper from unmapping private anonymous
memory with the oom reaper when the oom victim mm had mmu notifiers
registered.

The rationale is that doing mmu_notifier_invalidate_range_{start,end}()
around the unmap_page_range(), which is needed, can block and the oom
killer will stall forever waiting for the victim to exit, which may not
be possible without reaping.

That concern is real, but only true for mmu notifiers that have
blockable invalidate_range_{start,end}() callbacks.  This patch adds a
"flags" field to mmu notifier ops that can set a bit to indicate that
these callbacks do not block.

The implementation is steered toward an expensive slowpath, such as
after the oom reaper has grabbed mm->mmap_sem of a still alive oom
victim.

[rientjes@google.com: mmu_notifier_invalidate_range_end() can also call the invalidate_range() must not block, fix comment]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1801091339570.240101@chino.kir.corp.google.com
[akpm@linux-foundation.org: make mm_has_blockable_invalidate_notifiers() return bool, use rwsem_is_locked()]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1712141329500.74052@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Dimitri Sivanich <sivanich@hpe.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: thp: use down_read_trylock() in khugepaged to avoid long block
Yang Shi [Thu, 1 Feb 2018 00:18:28 +0000 (16:18 -0800)]
mm: thp: use down_read_trylock() in khugepaged to avoid long block

In the current design, khugepaged needs to acquire mmap_sem before
scanning an mm.  But in some corner cases, khugepaged may scan a process
which is modifying its memory mapping, so khugepaged blocks in
uninterruptible state.  But the process might hold the mmap_sem for a
long time when modifying a huge memory space and it may trigger the
below khugepaged hung issue:

  INFO: task khugepaged:270 blocked for more than 120 seconds.
  Tainted: G E 4.9.65-006.ali3000.alios7.x86_64 #1
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  khugepaged D 0 270 2 0x00000000 
  ffff883f3deae4c0 0000000000000000 ffff883f610596c0 ffff883f7d359440
  ffff883f63818000 ffffc90019adfc78 ffffffff817079a5 d67e5aa8c1860a64
  0000000000000246 ffff883f7d359440 ffffc90019adfc88 ffff883f610596c0
  Call Trace:
    schedule+0x36/0x80
    rwsem_down_read_failed+0xf0/0x150
    call_rwsem_down_read_failed+0x18/0x30
    down_read+0x20/0x40
    khugepaged+0x476/0x11d0
    kthread+0xe6/0x100
    ret_from_fork+0x25/0x30

So it sounds pointless to just block khugepaged waiting for the
semaphore so replace down_read() with down_read_trylock() to move to
scan the next mm quickly instead of just blocking on the semaphore so
that other processes can get more chances to install THP.  Then
khugepaged can come back to scan the skipped mm when it has finished the
current round full_scan.

And it appears that the change can improve khugepaged efficiency a
little bit.

Below is the test result when running LTP on a 24 cores 4GB memory 2
nodes NUMA VM:

                                    pristine          w/ trylock
  full_scan                         197               187
  pages_collapsed                   21                26
  thp_fault_alloc                   40818             44466
  thp_fault_fallback                18413             16679
  thp_collapse_alloc                21                150
  thp_collapse_alloc_failed         14                16
  thp_file_alloc                    369               369

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: tweak comment]
[arnd@arndb.de: avoid uninitialized variable use]
Link: http://lkml.kernel.org/r/20171215125129.2948634-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/1513281203-54878-1-git-send-email-yang.s@alibaba-inc.com
Signed-off-by: Yang Shi <yang.s@alibaba-inc.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/thp: remove pmd_huge_split_prepare()
Aneesh Kumar K.V [Thu, 1 Feb 2018 00:18:24 +0000 (16:18 -0800)]
mm/thp: remove pmd_huge_split_prepare()

Instead of marking the pmd ready for split, invalidate the pmd.  This
should take care of powerpc requirement.  Only side effect is that we
mark the pmd invalid early.  This can result in us blocking access to
the page a bit longer if we race against a thp split.

[kirill.shutemov@linux.intel.com: rebased, dirty THP once]
Link: http://lkml.kernel.org/r/20171213105756.69879-13-kirill.shutemov@linux.intel.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Daney <david.daney@cavium.com>
Cc: David Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitin Gupta <nitin.m.gupta@oracle.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: use updated pmdp_invalidate() interface to track dirty/accessed bits
Kirill A. Shutemov [Thu, 1 Feb 2018 00:18:20 +0000 (16:18 -0800)]
mm: use updated pmdp_invalidate() interface to track dirty/accessed bits

Use the modifed pmdp_invalidate() that returns the previous value of pmd
to transfer dirty and accessed bits.

Link: http://lkml.kernel.org/r/20171213105756.69879-12-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Daney <david.daney@cavium.com>
Cc: David Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitin Gupta <nitin.m.gupta@oracle.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: do not lose dirty and accessed bits in pmdp_invalidate()
Kirill A. Shutemov [Thu, 1 Feb 2018 00:18:16 +0000 (16:18 -0800)]
mm: do not lose dirty and accessed bits in pmdp_invalidate()

Vlastimil noted that pmdp_invalidate() is not atomic and we can lose
dirty and access bits if CPU sets them after pmdp dereference, but
before set_pmd_at().

The patch change pmdp_invalidate() to make the entry non-present
atomically and return previous value of the entry.  This value can be
used to check if CPU set dirty/accessed bits under us.

The race window is very small and I haven't seen any reports that can be
attributed to the bug.  For this reason, I don't think backporting to
stable trees needed.

Link: http://lkml.kernel.org/r/20171213105756.69879-11-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Daney <david.daney@cavium.com>
Cc: David Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitin Gupta <nitin.m.gupta@oracle.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agox86/mm: provide pmdp_establish() helper
Kirill A. Shutemov [Thu, 1 Feb 2018 00:18:13 +0000 (16:18 -0800)]
x86/mm: provide pmdp_establish() helper

We need an atomic way to setup pmd page table entry, avoiding races with
CPU setting dirty/accessed bits.  This is required to implement
pmdp_invalidate() that doesn't lose these bits.

On PAE we can avoid expensive cmpxchg8b for cases when new page table
entry is not present.  If it's present, fallback to cpmxchg loop.

[akpm@linux-foundation.org: add missing `do' to do-while loop]
Link: http://lkml.kernel.org/r/20171213105756.69879-10-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agosparc64: update pmdp_invalidate() to return old pmd value
Nitin Gupta [Thu, 1 Feb 2018 00:18:09 +0000 (16:18 -0800)]
sparc64: update pmdp_invalidate() to return old pmd value

It's required to avoid losing dirty and accessed bits.

[akpm@linux-foundation.org: add a `do' to the do-while loop]
Link: http://lkml.kernel.org/r/20171213105756.69879-9-kirill.shutemov@linux.intel.com
Signed-off-by: Nitin Gupta <nitin.m.gupta@oracle.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agos390/mm: modify pmdp_invalidate to return old value.
Martin Schwidefsky [Thu, 1 Feb 2018 00:18:05 +0000 (16:18 -0800)]
s390/mm: modify pmdp_invalidate to return old value.

It's required to avoid losing dirty and accessed bits.

Link: http://lkml.kernel.org/r/20171213105756.69879-8-kirill.shutemov@linux.intel.com
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agopowerpc/mm: update pmdp_invalidate to return old pmd value
Aneesh Kumar K.V [Thu, 1 Feb 2018 00:18:02 +0000 (16:18 -0800)]
powerpc/mm: update pmdp_invalidate to return old pmd value

It's required to avoid losing dirty and accessed bits.

Link: http://lkml.kernel.org/r/20171213105756.69879-7-kirill.shutemov@linux.intel.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomips: use generic_pmdp_establish as pmdp_establish
Kirill A. Shutemov [Thu, 1 Feb 2018 00:17:58 +0000 (16:17 -0800)]
mips: use generic_pmdp_establish as pmdp_establish

MIPS doesn't support hardware dirty/accessed bits.
generic_pmdp_establish() is suitable in this case.

Link: http://lkml.kernel.org/r/20171213105756.69879-6-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoarm64: provide pmdp_establish() helper
Catalin Marinas [Thu, 1 Feb 2018 00:17:55 +0000 (16:17 -0800)]
arm64: provide pmdp_establish() helper

We need an atomic way to setup pmd page table entry, avoiding races with
CPU setting dirty/accessed bits.  This is required to implement
pmdp_invalidate() that doesn't lose these bits.

Link: http://lkml.kernel.org/r/20171213105756.69879-5-kirill.shutemov@linux.intel.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoarm/mm: provide pmdp_establish() helper
Kirill A. Shutemov [Thu, 1 Feb 2018 00:17:51 +0000 (16:17 -0800)]
arm/mm: provide pmdp_establish() helper

ARM LPAE doesn't have hardware dirty/accessed bits.

generic_pmdp_establish() is the right implementation of pmdp_establish
for this case.

Link: http://lkml.kernel.org/r/20171213105756.69879-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoarc: use generic_pmdp_establish as pmdp_establish
Kirill A. Shutemov [Thu, 1 Feb 2018 00:17:48 +0000 (16:17 -0800)]
arc: use generic_pmdp_establish as pmdp_establish

ARC doesn't support hardware dirty/accessed bits.
generic_pmdp_establish() is suitable in this case.

Link: http://lkml.kernel.org/r/20171213105756.69879-3-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoasm-generic: provide generic_pmdp_establish()
Kirill A. Shutemov [Thu, 1 Feb 2018 00:17:43 +0000 (16:17 -0800)]
asm-generic: provide generic_pmdp_establish()

Patch series "Do not lose dirty bit on THP pages", v4.

Vlastimil noted that pmdp_invalidate() is not atomic and we can lose
dirty and access bits if CPU sets them after pmdp dereference, but
before set_pmd_at().

The bug can lead to data loss, but the race window is tiny and I haven't
seen any reports that suggested that it happens in reality.  So I don't
think it worth sending it to stable.

Unfortunately, there's no way to address the issue in a generic way.  We
need to fix all architectures that support THP one-by-one.

All architectures that have THP supported have to provide atomic
pmdp_invalidate() that returns previous value.

If generic implementation of pmdp_invalidate() is used, architecture
needs to provide atomic pmdp_estabish().

pmdp_estabish() is not used out-side generic implementation of
pmdp_invalidate() so far, but I think this can change in the future.

This patch (of 12):

This is an implementation of pmdp_establish() that is only suitable for
an architecture that doesn't have hardware dirty/accessed bits.  In this
case we can't race with CPU which sets these bits and non-atomic
approach is fine.

Link: http://lkml.kernel.org/r/20171213105756.69879-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Daney <david.daney@cavium.com>
Cc: David Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nitin Gupta <nitin.m.gupta@oracle.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: get 7% more pages in a pagevec
Matthew Wilcox [Thu, 1 Feb 2018 00:17:40 +0000 (16:17 -0800)]
mm: get 7% more pages in a pagevec

We don't have to use an entire 'long' for the number of elements in the
pagevec; we know it's a number between 0 and 14 (now 15).  So we can
store it in a char, and then the bool packs next to it and we still have
two or six bytes of padding for more elements in the header.  That gives
us space to cram in an extra page.

Link: http://lkml.kernel.org/r/20171206022521.GM26021@bombadil.infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: add unmap_mapping_pages()
Matthew Wilcox [Thu, 1 Feb 2018 00:17:36 +0000 (16:17 -0800)]
mm: add unmap_mapping_pages()

Several users of unmap_mapping_range() would prefer to express their
range in pages rather than bytes.  Unfortuately, on a 32-bit kernel, you
have to remember to cast your page number to a 64-bit type before
shifting it, and four places in the current tree didn't remember to do
that.  That's a sign of a bad interface.

Conveniently, unmap_mapping_range() actually converts from bytes into
pages, so hoist the guts of unmap_mapping_range() into a new function
unmap_mapping_pages() and convert the callers which want to use pages.

Link: http://lkml.kernel.org/r/20171206142627.GD32044@bombadil.infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.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>
2 years agomm, userfaultfd, THP: avoid waiting when PMD under THP migration
Huang Ying [Thu, 1 Feb 2018 00:17:32 +0000 (16:17 -0800)]
mm, userfaultfd, THP: avoid waiting when PMD under THP migration

If THP migration is enabled, for a VMA handled by userfaultfd, consider
the following situation,

  do_page_fault()
    __do_huge_pmd_anonymous_page()
     handle_userfault()
       userfault_msg()
         /* a huge page is allocated and mapped at fault address */
         /* the huge page is under migration, leaves migration entry
            in page table */
       userfaultfd_must_wait()
         /* return true because !pmd_present() */
       /* may wait in loop until fatal signal */

That is, it may be possible for userfaultfd_must_wait() encounters a PMD
entry which is !pmd_none() && !pmd_present().  In the current
implementation, we will wait for such PMD entries, which may cause
unnecessary waiting, and potential soft lockup.

This is fixed via avoiding to wait when !pmd_none() && !pmd_present(),
only wait when pmd_none().

This may be not a problem in practice, because userfaultfd_must_wait()
is always called with mm->mmap_sem read-locked.  mremap() will
write-lock mm->mmap_sem.  And UFFDIO_COPY doesn't support to copy THP
mapping.  But the change introduced still makes the code more correct,
and makes the PMD and PTE code more consistent.

Link: http://lkml.kernel.org/r/20171207011752.3292-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.UK>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/huge_memory.c: fix comment in __split_huge_pmd_locked
Yisheng Xie [Thu, 1 Feb 2018 00:17:29 +0000 (16:17 -0800)]
mm/huge_memory.c: fix comment in __split_huge_pmd_locked

pmd_trans_splitting() was removed after THP refcounting redesign,
therefore related comment should be updated.

Link: http://lkml.kernel.org/r/1512625745-59451-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.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>
2 years agomm: memory_hotplug: remove second __nr_to_section in register_page_bootmem_info_section()
Oscar Salvador [Thu, 1 Feb 2018 00:17:25 +0000 (16:17 -0800)]
mm: memory_hotplug: remove second __nr_to_section in register_page_bootmem_info_section()

In register_page_bootmem_info_section() we call __nr_to_section() in
order to get the mem_section struct at the beginning of the function.
Since we already got it, there is no need for a second call to
__nr_to_section().

Link: http://lkml.kernel.org/r/20171207102914.GA12396@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@techadventures.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agofs/proc/task_mmu.c: do not show VmExe bigger than total executable virtual memory
Konstantin Khlebnikov [Thu, 1 Feb 2018 00:17:22 +0000 (16:17 -0800)]
fs/proc/task_mmu.c: do not show VmExe bigger than total executable virtual memory

If start_code / end_code pointers are screwed then "VmExe" could be
bigger than total executable virtual memory and "VmLib" becomes
negative:

  VmExe:   294320 kB
  VmLib: 18446744073709327564 kB

VmExe and VmLib documented as text segment and shared library code size.

Now their sum will be always equal to mm->exec_vm which sums size of
executable and not writable and not stack areas.

I've seen this for huge (>2Gb) statically linked binary which has whole
world inside.  For it start_code ..  end_code range also covers one of
rodata sections.  Probably this is bug in customized linker, elf loader
or both.

Anyway CONFIG_CHECKPOINT_RESTORE allows to change these pointers, thus
we cannot trust them without validation.

Link: http://lkml.kernel.org/r/150728955451.743749.11276392315459539583.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
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>
2 years agomm: update comment describing tlb_gather_mmu
Mike Rapoport [Thu, 1 Feb 2018 00:17:17 +0000 (16:17 -0800)]
mm: update comment describing tlb_gather_mmu

The comment describes @fullmm argument, but the function has no such
parameter.

Update the comment to match the code and convert it to kernel-doc
markup.

Link: http://lkml.kernel.org/r/1512394531-2264-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/memory_hotplug.c: remove unnecesary check from register_page_bootmem_info_section()
Oscar Salvador [Thu, 1 Feb 2018 00:17:14 +0000 (16:17 -0800)]
mm/memory_hotplug.c: remove unnecesary check from register_page_bootmem_info_section()

When we call register_page_bootmem_info_section() having
CONFIG_SPARSEMEM_VMEMMAP enabled, we check if the pfn is valid.

This check is redundant as we already checked this in
register_page_bootmem_info_node() before calling
register_page_bootmem_info_section(), so let's get rid of it.

Link: http://lkml.kernel.org/r/20171205143422.GA31458@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@techadventures.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm, hugetlb: remove hugepages_treat_as_movable sysctl
Michal Hocko [Thu, 1 Feb 2018 00:17:10 +0000 (16:17 -0800)]
mm, hugetlb: remove hugepages_treat_as_movable sysctl

hugepages_treat_as_movable has been introduced by 396faf0303d2 ("Allow
huge page allocations to use GFP_HIGH_MOVABLE") to allow hugetlb
allocations from ZONE_MOVABLE even when hugetlb pages were not
migrateable.  The purpose of the movable zone was different at the time.
It aimed at reducing memory fragmentation and hugetlb pages being long
lived and large werre not contributing to the fragmentation so it was
acceptable to use the zone back then.

Things have changed though and the primary purpose of the zone became
migratability guarantee.  If we allow non migrateable hugetlb pages to
be in ZONE_MOVABLE memory hotplug might fail to offline the memory.

Remove the knob and only rely on hugepage_migration_supported to allow
movable zones.

Mel said:

: Primarily it was aimed at allowing the hugetlb pool to safely shrink with
: the ability to grow it again.  The use case was for batched jobs, some of
: which needed huge pages and others that did not but didn't want the memory
: useless pinned in the huge pages pool.
:
: I suspect that more users rely on THP than hugetlbfs for flexible use of
: huge pages with fallback options so I think that removing the option
: should be ok.

Link: http://lkml.kernel.org/r/20171003072619.8654-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Alexandru Moise <00moses.alexander00@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Alexandru Moise <00moses.alexander00@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm: remove unused pgdat_reclaimable_pages()
Jan Kara [Thu, 1 Feb 2018 00:17:06 +0000 (16:17 -0800)]
mm: remove unused pgdat_reclaimable_pages()

Remove unused function pgdat_reclaimable_pages() and
node_page_state_snapshot() which becomes unused as well.

Link: http://lkml.kernel.org/r/20171122094416.26019-1-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agomm/interval_tree.c: use vma_pages() helper
Vasyl Gomonovych [Thu, 1 Feb 2018 00:17:03 +0000 (16:17 -0800)]
mm/interval_tree.c: use vma_pages() helper

Use vma_pages function on vma object instead of explicit computation.

  mm/interval_tree.c:21:27-33: WARNING: Consider using vma_pages helper

Generated by: scripts/coccinelle/api/vma_pages.cocci

Link: http://lkml.kernel.org/r/1511364410-13499-1-git-send-email-gomonovych@gmail.com
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2 years agoselftests/vm: move 128TB mmap boundary test to generic directory
Aneesh Kumar K.V [Thu, 1 Feb 2018 00:16:59 +0000 (16:16 -0800)]
selftests/vm: move 128TB mmap boundary test to generic directory

Architectures like PPC64 support mmap hint address based large address
space selection.  This test can be run on those architectures too.  Move
the test from the x86 selftests to selftest/vm so that other
architectures can use it too.

We also add a few new test scenarios in this patch.  We do test a few
boundary conditions before we do a high address mmap.  PPC64 uses the
address limit to validate the address in the fault path.  We had bugs in
this area w.r.t SLB fault handling before we updated the addess limit.

We also touch the allocated space to make sure we don't have any bugs in
the fault handling path.

[akpm@linux-foundation.org: restore tools/testing/selftests/vm/Makefile alpha ordering]
Link: http://lkml.kernel.org/r/20171123165226.32582-1-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>