This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Crispin <blogic@openwrt.org>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull support for killable rwsems from Ingo Molnar:
 "This, by Michal Hocko, implements down_write_killable().

  The main usecase will be to update mm_sem usage sites to use this new
  API, to allow the mm-reaper introduced in commit aac453635549 ("mm,
  oom: introduce oom reaper") to tear down oom victim address spaces
  asynchronously with minimum latencies and without deadlock worries"

[ The vfs will want it too as the inode lock is changed from a mutex to
  a rwsem due to the parallel lookup and readdir updates ]

* 'locking-rwsem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Fix comment on register clobbering
  locking/rwsem: Fix down_write_killable()
  locking/rwsem, x86: Add frame annotation for call_rwsem_down_write_failed_killable()
  locking/rwsem: Provide down_write_killable()
  locking/rwsem, x86: Provide __down_write_killable()
  locking/rwsem, s390: Provide __down_write_killable()
  locking/rwsem, ia64: Provide __down_write_killable()
  locking/rwsem, alpha: Provide __down_write_killable()
  locking/rwsem: Introduce basis for down_write_killable()
  locking/rwsem, sparc: Drop superfluous arch specific implementation
  locking/rwsem, sh: Drop superfluous arch specific implementation
  locking/rwsem, xtensa: Drop superfluous arch specific implementation
  locking/rwsem: Drop explicit memory barriers
  locking/rwsem: Get rid of __down_write_nested()

Since "locking, rwsem: drop explicit memory barriers" the arch specific
code is basically same as the the generic one so we can drop the
superfluous code.

Suggested-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Signed-off-by: Jason Low <jason.low2@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1460041951-22347-5-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

sh and xtensa seem to be the only architectures which use explicit
memory barriers for rw_semaphore operations even though they are not
really needed because there is the full memory barrier is always implied
by atomic_{inc,dec,add,sub}_return() resp. cmpxchg(). Remove them.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Signed-off-by: Jason Low <jason.low2@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1460041951-22347-3-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This is no longer used anywhere and all callers (__down_write()) use
0 as a subclass. Ditch __down_write_nested() to make the code easier
to follow.

This shouldn't introduce any functional change.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Signed-off-by: Jason Low <jason.low2@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1460041951-22347-2-git-send-email-mhocko@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

The signedness mismatch of the argument type produces an error
compiling kernel/sched/core.c with -Werror=incompatible-pointer-types,
which is now used by default.

Fixes: ea8daa7b9784 "kbuild: Add option to turn incompatible pointer check into error"
Signed-off-by: Rich Felker <dalias@libc.org>

The removal was not complete and left behind one reference to a
removed function in smp-shx3.c. For completeness, also remove
declarations for functions that were removed.

Fixes: 45624ac38926 "sh: remove arch-specific localtimer and use generic one"
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Rich Felker <dalias@libc.org>

Pull arch/sh updates from Rich Felker:
 "This includes minor cleanups, a fix for a crash that likely affects
  all sh models with MMU, and introduction of a framework for boards
  described by device tree, which sets the stage for future J2 support"

* tag 'tag-sh-for-4.6' of git://git.libc.org/linux-sh:
  sched/preempt, sh: kmap_coherent relies on disabled preemption
  sh: add SMP method selection to device tree pseudo-board
  sh: add device tree support and generic board using device tree
  sh: remove arch-specific localtimer and use generic one
  sh: make MMU-specific SMP code conditional on CONFIG_MMU
  sh: provide unified syscall trap compatible with all SH models
  sh: New gcc support
  sh: Disable trace for kernel uncompressing.
  sh: Use generic clkdev.h header

Pull networking updates from David Miller:
 "Highlights:

   1) Support more Realtek wireless chips, from Jes Sorenson.

   2) New BPF types for per-cpu hash and arrap maps, from Alexei
      Starovoitov.

   3) Make several TCP sysctls per-namespace, from Nikolay Borisov.

   4) Allow the use of SO_REUSEPORT in order to do per-thread processing
   of incoming TCP/UDP connections.  The muxing can be done using a
   BPF program which hashes the incoming packet.  From Craig Gallek.

   5) Add a multiplexer for TCP streams, to provide a messaged based
      interface.  BPF programs can be used to determine the message
      boundaries.  From Tom Herbert.

   6) Add 802.1AE MACSEC support, from Sabrina Dubroca.

   7) Avoid factorial complexity when taking down an inetdev interface
      with lots of configured addresses.  We were doing things like
      traversing the entire address less for each address removed, and
      flushing the entire netfilter conntrack table for every address as
      well.

   8) Add and use SKB bulk free infrastructure, from Jesper Brouer.

   9) Allow offloading u32 classifiers to hardware, and implement for
      ixgbe, from John Fastabend.

  10) Allow configuring IRQ coalescing parameters on a per-queue basis,
      from Kan Liang.

  11) Extend ethtool so that larger link mode masks can be supported.
      From David Decotigny.

  12) Introduce devlink, which can be used to configure port link types
      (ethernet vs Infiniband, etc.), port splitting, and switch device
      level attributes as a whole.  From Jiri Pirko.

  13) Hardware offload support for flower classifiers, from Amir Vadai.

  14) Add "Local Checksum Offload".  Basically, for a tunneled packet
      the checksum of the outer header is 'constant' (because with the
      checksum field filled into the inner protocol header, the payload
      of the outer frame checksums to 'zero'), and we can take advantage
      of that in various ways.  From Edward Cree"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits)
  bonding: fix bond_get_stats()
  net: bcmgenet: fix dma api length mismatch
  net/mlx4_core: Fix backward compatibility on VFs
  phy: mdio-thunder: Fix some Kconfig typos
  lan78xx: add ndo_get_stats64
  lan78xx: handle statistics counter rollover
  RDS: TCP: Remove unused constant
  RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket
  net: smc911x: convert pxa dma to dmaengine
  team: remove duplicate set of flag IFF_MULTICAST
  bonding: remove duplicate set of flag IFF_MULTICAST
  net: fix a comment typo
  ethernet: micrel: fix some error codes
  ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it
  bpf, dst: add and use dst_tclassid helper
  bpf: make skb->tc_classid also readable
  net: mvneta: bm: clarify dependencies
  cls_bpf: reset class and reuse major in da
  ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c
  ldmvsw: Add ldmvsw.c driver code
  ...

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO changes for kernel v4.6.  There is quite a
  lot of interesting stuff going on.

  The patches to other subsystems and arch-wide are ACKed as far as
  possible, though I consider things like per-arch <asm/gpio.h> as
  essentially a part of the GPIO subsystem so it should not be needed.

  Core changes:

   - The gpio_chip is now a *real device*.  Until now the gpio chips
     were just piggybacking the parent device or (gasp) floating in
     space outside of the device model.

     We now finally make GPIO chips devices.  The gpio_chip will create
     a gpio_device which contains a struct device, and this gpio_device
     struct is kept private.  Anything that needs to be kept private
     from the rest of the kernel will gradually be moved over to the
     gpio_device.

   - As a result of making the gpio_device a real device, we have added
     resource management, so devm_gpiochip_add_data() will cut down on
     overhead and reduce code lines.  A huge slew of patches convert
     almost all drivers in the subsystem to use this.

   - Building on making the GPIO a real device, we add the first step of
     a new userspace ABI: the GPIO character device.  We take small
     steps here, so we first add a pure *information* ABI and the tool
     "lsgpio" that will list all GPIO devices on the system and all
     lines on these devices.

     We can now discover GPIOs properly from userspace.  We still have
     not come up with a way to actually *use* GPIOs from userspace.

   - To encourage people to use the character device for the future, we
     have it always-enabled when using GPIO.  The old sysfs ABI is still
     opt-in (and can be used in parallel), but is marked as deprecated.

     We will keep it around for the foreseeable future, but it will not
     be extended to cover ever more use cases.

  Cleanup:

   - Bjorn Helgaas removed a whole slew of per-architecture <asm/gpio.h>
     includes.

     This dates back to when GPIO was an opt-in feature and no shared
     library even existed: just a header file with proper prototypes was
     provided and all semantics were up to the arch to implement.  These
     patches make the GPIO chip even more a proper device and cleans out
     leftovers of the old in-kernel API here and there.

     Still some cruft is left but it's very little now.

   - There is still some clamping of return values for .get() going on,
     but we now return sane values in the vast majority of drivers and
     the errorpath is sanitized.  Some patches for powerpc, blackfin and
     unicore still drop in.

   - We continue to switch the ARM, MIPS, blackfin, m68k local GPIO
     implementations to use gpiochip_add_data() and cut down on code
     lines.

   - MPC8xxx is converted to use the generic GPIO helpers.

   - ATH79 is converted to use the generic GPIO helpers.

  New drivers:

   - WinSystems WS16C48

   - Acces 104-DIO-48E

   - F81866 (a F7188x variant)

   - Qoric (a MPC8xxx variant)

   - TS-4800

   - SPI serializers (pisosr): simple 74xx shift registers connected to
     SPI to obtain a dirt-cheap output-only GPIO expander.

   - Texas Instruments TPIC2810

   - Texas Instruments TPS65218

   - Texas Instruments TPS65912

   - X-Gene (ARM64) standby GPIO controller"

* tag 'gpio-v4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (194 commits)
  Revert "Share upstreaming patches"
  gpio: mcp23s08: Fix clearing of interrupt.
  gpiolib: Fix comment referring to gpio_*() in gpiod_*()
  gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit
  gpio: xgene: Fix kconfig for standby GIPO contoller
  gpio: Add generic serializer DT binding
  gpio: uapi: use 0xB4 as ioctl() major
  gpio: tps65912: fix bad merge
  Revert "gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free"
  gpio: omap: drop dev field from gpio_bank structure
  gpio: mpc8xxx: Slightly update the code for better readability
  gpio: mpc8xxx: Remove *read_reg and *write_reg from struct mpc8xxx_gpio_chip
  gpio: mpc8xxx: Fixup setting gpio direction output
  gpio: mcp23s08: Add support for mcp23s18
  dt-bindings: gpio: altera: Fix altr,interrupt-type property
  gpio: add driver for MEN 16Z127 GPIO controller
  gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free
  gpio: timberdale: Switch to devm_ioremap_resource()
  gpio: ts4800: Add IMX51 dependency
  gpiolib: rewrite gpiodev_add_to_list
  ...