[suggested by Rasmus Villemoes] make O_DIRECTORY | O_RDWR part of O_TMPFILE;
that will fail on old kernels in a lot more cases than what I came up with.
And make sure O_CREAT doesn't get there...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The file_lock_list is only used for /proc/locks. The vastly common case
is for locks to be put onto the list and come off again, without ever
being traversed.

Help optimize for this use-case by moving to percpu hlist_head-s. At the
same time, we can make the locking less contentious by moving to an
lglock. When iterating over the lists for /proc/locks, we must take the
global lock and then iterate over each CPU's list in turn.

This change necessitates a new fl_link_cpu field to keep track of which
CPU the entry is on. On x86_64 at least, this field is placed within an
existing hole in the struct to avoid growing the size.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

When we convert the file_lock_list to a set of percpu lists, we'll need
a way to iterate over them in order to output /proc/locks info. Add
some seq_list_*_percpu helpers to handle that.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Currently, when a disconnect is requested by the user (via NBD_DISCONNECT
ioctl) the return from NBD_DO_IT is undefined (it is usually one of
several error codes).  This means that nbd-client does not know if a
manual disconnect was performed or whether a network error occurred.
Because of this, nbd-client's persist mode (which tries to reconnect after
error, but not after manual disconnect) does not always work correctly.

This change fixes this by causing NBD_DO_IT to always return 0 if a user
requests a disconnect.  This means that nbd-client can correctly either
persist the connection (if an error occurred) or disconnect (if the user
requested it).
Signed-off-by: NPaul Clements <paul.clements@steeleye.com>
Acked-by: NRob Landley <rob@landley.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change endpoint device name format to use a component tag value instead of
device destination ID.

RapidIO specification defines a component tag to be a unique identifier
for devices in a network.  RapidIO switches already use component tag as
part of their device name and also use it for device identification when
processing error management event notifications.

Forming an endpoint's device name using its component tag instead of
destination ID allows to keep sysfs device directories unchanged in case
if a routing process dynamically changes endpoint's destination ID as a
result of route optimization.

This change should not affect any existing users because a valid device
destination ID always should be obtained by reading "destid" attribute and
not by parsing device name.

This patch also removes switchid member from struct rio_switch because it
simply duplicates the component tag and does not have other use than in
device name generation.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Stef van Os <stef.van.os@Prodrive.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add RapidIO-specific modalias generation to enable udev notifications
about RapidIO-specific events.

The RapidIO modalias string format is shown below:

"rapidio:vNNNNdNNNNavNNNNadNNNN"

Where:
v  - Device Vendor ID (16 bit),
d  - Device ID (16 bit),
av - Assembly Vendor ID (16 bit),
ad - Assembly ID (16 bit),

as they are reported in corresponding Capability Registers (CARs)
of each RapidIO device.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Stef van Os <stef.van.os@Prodrive.nl>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update enumeration/discovery method registration mechanism to allow
loading enumeration/discovery methods before all mports are registered.

Existing statically linked RapidIO subsystem expects that all available
RapidIO mport devices are initialized and registered before the
enumeration/discovery method is registered.  Switching to loadable mport
device drivers creates situation when mport device driver can be loaded
after enumeration/discovery method is attached (e.g., loadable mport
driver in a system with statically linked RapidIO core and enumerator).
This also will happen in a system with hot-pluggable RapidIO controllers.

To remove the dependency on the initialization/registration order this
patch introduces enumeration/discovery registration mechanism that
supports arbitrary registration order of mports and enumerator/discovery
methods.

The following registration rules are implemented:
- only one enumeration/discovery method can be registered for given mport ID
  (including RIO_MPORT_ANY);
- when new enumeration/discovery methods tries to attach to the registered mport
  device, method with matching mport ID will replace a default method previously
  registered for given mport (if any);
- enumeration/discovery method with target ID=RIO_MPORT_ANY will be attached
  only to mports that do not have another enumerator attached to them;
- when new mport device is registered with RapidIO subsystem, registration
  routine searches for the enumeration/discovery method with the best matching
  mport ID;
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Stef van Os <stef.van.os@Prodrive.nl>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rework RapidIO switch drivers to add an option to build them as loadable
kernel modules.

This patch removes RapidIO-specific vmlinux section and converts switch
drivers to be compatible with LDM driver registration method.  To simplify
registration of device-specific callback routines this patch introduces
rio_switch_ops data structure.  The sw_sysfs() callback is removed from
the list of device-specific operations because under the new structure its
functions can be handled by switch driver's probe() and remove() routines.

If a specific switch device driver is not loaded the RapidIO subsystem
core will use default standard-based operations to configure a switch.
Because the current implementation of RapidIO enumeration/discovery method
relies on availability of device-specific operations for error management,
switch device drivers must be loaded before the RapidIO
enumeration/discovery starts.

This patch also moves several common routines from enumeration/discovery
module into the RapidIO core code to make switch-specific operations
accessible to all components of RapidIO subsystem.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@Prodrive.nl>
Cc: Micha Nelissen <micha.nelissen@Prodrive.nl>
Cc: Stef van Os <stef.van.os@Prodrive.nl>
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

copy_process() adds the new child to thread_group/init_task.tasks list and
then does attach_pid(child, PIDTYPE_PID).  This means that the lockless
next_thread() or next_task() can see this thread with the wrong pid.  Say,
"ls /proc/pid/task" can list the same inode twice.

We could move attach_pid(child, PIDTYPE_PID) up, but in this case
find_task_by_vpid() can find the new thread before it was fully
initialized.

And this is already true for PIDTYPE_PGID/PIDTYPE_SID, With this patch
copy_process() initializes child->pids[*].pid first, then calls
attach_pid() to insert the task into the pid->tasks list.

attach_pid() no longer need the "struct pid*" argument, it is always
called after pid_link->pid was already set.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move __set_special_pids() from exit.c to sys.c close to its single caller
and make it static.

And rename it to set_special_pids(), another helper with this name has
gone away.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

crtools uses a parasite code for dumping processes.  The parasite code is
injected into a process with help PTRACE_SEIZE.

Currently crtools blocks signals from a parasite code.  If a process has
pending signals, crtools wait while a process handles these signals.

This method is not suitable for stopped tasks.  A stopped task can have a
few pending signals, when we will try to execute a parasite code, we will
need to drop SIGSTOP, but all other signals must remain pending, because a
state of processes must not be changed during checkpointing.

This patch adds two ptrace commands to set/get signal-blocked mask.

I think gdb can use this commands too.

[akpm@linux-foundation.org: be consistent with brace layout]
Signed-off-by: NAndrey Vagin <avagin@openvz.org>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These functions allow the driver core to automatically clean up any
allocation made by lcd drivers.  Thus it simplifies the error paths.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These functions allow the driver core to automatically clean up any
allocation made by backlight drivers.  Thus it simplifies the error
paths.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There have never been any real users of MEMSET operations since they
have been introduced in January 2007 by commit 7405f74b ("dmaengine:
refactor dmaengine around dma_async_tx_descriptor").  Therefore remove
support for them for now, it can be always brought back when needed.

[sebastian.hesselbarth@gmail.com: fix drivers/dma/mv_xor]
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Acked-by: NDan Williams <djbw@fb.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Olof Johansson <olof@lixom.net>
Cc: Kevin Hilman <khilman@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dmi_match() considers a substring match to be a successful match.  This is
not always sufficient to distinguish between DMI data for different
systems.  Add support for exact string matching using strcmp() in addition
to the substring matching using strstr().

The specific use case in the i915 driver is to allow us to use an exact
match for D510MO, without also incorrectly matching D510MOV:

  {
	.ident = "Intel D510MO",
	.matches = {
		DMI_MATCH(DMI_BOARD_VENDOR, "Intel"),
		DMI_EXACT_MATCH(DMI_BOARD_NAME, "D510MO"),
	},
  }
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Cc: <annndddrr@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Cornel Panceac <cpanceac@gmail.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For the workqueue creation interfaces that do not expect format strings,
make sure they cannot accidently be parsed that way.  Additionally, clean
up calls made with a single parameter that would be handled as a format
string.  Many callers are passing potentially dynamic string content, so
use "%s" in those cases to avoid any potential accidents.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sparse generates a false positive when you pass a __user or __iomem
pointer to the IS_ERR() functions.

  drivers/rtc/rtc-ds1286.c:344:36: sparse: incorrect type in argument 1 (different address spaces)
  drivers/rtc/rtc-ds1286.c:344:36:    expected void const *ptr
  drivers/rtc/rtc-ds1286.c:344:36:    got unsigned int [noderef] [usertype] <asn:2>*rtcregs

We can silence these by adding a __force here and upgrading to Sparse
v0.4.5-rc1 or later.

This change has no effect when using current Sparse releases.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NChristopher Li <sparse@chrisli.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Instead of leaving a hidden trap for the next person who comes along and
wants to add something to mem_section, add a big fat warning about it
needing to be a power-of-2, and insert a BUILD_BUG_ON() in sparse_init()
to catch mistakes.

Right now non-power-of-2 mem_sections cause a number of WARNs at boot
(which don't clearly point to the size of mem_section as an issue), but
the system limps on (temporarily, at least).

This is based upon Dave Hansen's earlier RFC where he ran into the same
issue:
	"sparsemem: fix boot when SECTIONS_PER_ROOT is not power-of-2"
	http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/03077.htmlSigned-off-by: NCody P Schafer <cody@linux.vnet.ibm.com>
Acked-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now nobody makes use of free_all_bootmem_node(), kill it.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Yinghai Lu <yinghai@kernel.org>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduce a helper function set_max_mapnr() to set global variable
max_mapnr.

Also unify condition compilation for max_mapnr with
CONFIG_NEED_MULTIPLE_NODES instead of CONFIG_DISCONTIGMEM.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now all references to num_physpages have been removed, so kill it.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduce helper function mem_init_print_info() to simplify mem_init()
across different architectures, which also unifies the format and
information printed.

Function mem_init_print_info() calculates memory statistics information
without walking each page, so it should be a little faster on some
architectures.

Also introduce another helper get_num_physpages() to kill the global
variable num_physpages.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The original goal of this patchset is to fix the bug reported by
https://bugzilla.kernel.org/show_bug.cgi?id=53501 Now it has also been
expanded to reduce common code used by memory initializion.

Patch 1-7:
	1) add comments for global variables exported by vmlinux.lds
	2) normalize global variables exported by vmlinux.lds
Patch 8:
	Introduce helper functions mem_init_print_info() and
	get_num_physpages()
Patch 9:
	Avoid using global variable num_physpages at runtime
Patch 10:
	Don't update num_physpages in memory_hotplug.c
Patch 11-40:
	Modify arch mm initialization code to:
	1) Simplify mem_init() by using mem_init_print_info()
	2) Prepare for killing global variable num_physpages
Patch 41:
	Kill the global variable num_physpages

With all patches applied, mem_init(), free_initmem(), free_initrd_mem()
could be as simple as below.  This patch series has reduced about 1.2K
lines of code in total.

#ifndef CONFIG_DISCONTIGMEM
void __init
mem_init(void)
{
	max_mapnr = max_low_pfn;
	free_all_bootmem();
	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

	mem_init_print_info(NULL);
}
#endif /* CONFIG_DISCONTIGMEM */

void
free_initmem(void)
{
	free_initmem_default(-1);
}

#ifdef CONFIG_BLK_DEV_INITRD
void
free_initrd_mem(unsigned long start, unsigned long end)
{
	free_reserved_area(start, end, -1, "initrd");
}
#endif

Due to hardware resource limitations, I have only tested this on x86_64.
And the messages reported on an x86_64 system are:

Log message before applying patches:
Memory: 7745676k/8910848k available (6934k kernel code, 836024k absent, 329148k reserved, 6343k data, 1012k init)

Log message after applying patches:
Memory: 7744624K/8074824K available (6969K kernel code, 1011K data, 2828K rodata, 1016K init, 9640K bss, 330200K reserved)

Great thanks to Vineet Gupta for testing on ARC.

This patch:

Document global variables exported from vmlinux.lds.

1) Add comments about usage guidelines for global variables exported
   from vmlinux.lds.S.
2) Remove unused __initdata_begin[] and __initdata_end[].
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently lock_memory_hotplug()/unlock_memory_hotplug() are used to
protect totalram_pages and zone->managed_pages.  Other than the memory
hotplug driver, totalram_pages and zone->managed_pages may also be
modified at runtime by other drivers, such as Xen balloon,
virtio_balloon etc.  For those cases, memory hotplug lock is a little
too heavy, so introduce a dedicated lock to protect totalram_pages and
zone->managed_pages.

Now we have a simplified locking rules totalram_pages and
zone->managed_pages as:

1) no locking for read accesses because they are unsigned long.
2) no locking for write accesses at boot time in single-threaded context.
3) serialize write accesses at runtime by acquiring the dedicated
   managed_page_count_lock.

Also adjust zone->managed_pages when freeing reserved pages into the
buddy system, to keep totalram_pages and zone->managed_pages in
consistence.

[akpm@linux-foundation.org: don't export adjust_managed_page_count to modules (for now)]
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit "mm: introduce new field 'managed_pages' to struct zone" assumes
that all highmem pages will be freed into the buddy system by function
mem_init().  But that's not always true, some architectures may reserve
some highmem pages during boot.  For example PPC may allocate highmem
pages for giagant HugeTLB pages, and several architectures have code to
check PageReserved flag to exclude highmem pages allocated during boot
when freeing highmem pages into the buddy system.

So treat highmem pages in the same way as normal pages, that is to:
1) reset zone->managed_pages to zero in mem_init().
2) recalculate managed_pages when freeing pages into the buddy system.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Address more review comments from last round of code review.
1) Enhance free_reserved_area() to support poisoning freed memory with
   pattern '0'. This could be used to get rid of poison_init_mem()
   on ARM64.
2) A previous patch has disabled memory poison for initmem on s390
   by mistake, so restore to the original behavior.
3) Remove redundant PAGE_ALIGN() when calling free_reserved_area().
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change signature of free_reserved_area() according to Russell King's
suggestion to fix following build warnings:

  arch/arm/mm/init.c: In function 'mem_init':
  arch/arm/mm/init.c:603:2: warning: passing argument 1 of 'free_reserved_area' makes integer from pointer without a cast [enabled by default]
    free_reserved_area(__va(PHYS_PFN_OFFSET), swapper_pg_dir, 0, NULL);
    ^
  In file included from include/linux/mman.h:4:0,
                   from arch/arm/mm/init.c:15:
  include/linux/mm.h:1301:22: note: expected 'long unsigned int' but argument is of type 'void *'
   extern unsigned long free_reserved_area(unsigned long start, unsigned long end,

   mm/page_alloc.c: In function 'free_reserved_area':
>> mm/page_alloc.c:5134:3: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast [enabled by default]
   In file included from arch/mips/include/asm/page.h:49:0,
                    from include/linux/mmzone.h:20,
                    from include/linux/gfp.h:4,
                    from include/linux/mm.h:8,
                    from mm/page_alloc.c:18:
   arch/mips/include/asm/io.h:119:29: note: expected 'const volatile void *' but argument is of type 'long unsigned int'
   mm/page_alloc.c: In function 'free_area_init_nodes':
   mm/page_alloc.c:5030:34: warning: array subscript is below array bounds [-Warray-bounds]

Also address some minor code review comments.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Reported-by: NArnd Bergmann <arnd@arndb.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: <sworddragon2@aol.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Considering the use cases where the swap device supports discard:
a) and can do it quickly;
b) but it's slow to do in small granularities (or concurrent with other
   I/O);
c) but the implementation is so horrendous that you don't even want to
   send one down;

And assuming that the sysadmin considers it useful to send the discards down
at all, we would (probably) want the following solutions:

  i. do the fine-grained discards for freed swap pages, if device is
     capable of doing so optimally;
 ii. do single-time (batched) swap area discards, either at swapon
     or via something like fstrim (not implemented yet);
iii. allow doing both single-time and fine-grained discards; or
 iv. turn it off completely (default behavior)

As implemented today, one can only enable/disable discards for swap, but
one cannot select, for instance, solution (ii) on a swap device like (b)
even though the single-time discard is regarded to be interesting, or
necessary to the workload because it would imply (1), and the device is
not capable of performing it optimally.

This patch addresses the scenario depicted above by introducing a way to
ensure the (probably) wanted solutions (i, ii, iii and iv) can be flexibly
flagged through swapon(8) to allow a sysadmin to select the best suitable
swap discard policy accordingly to system constraints.

This patch introduces SWAP_FLAG_DISCARD_PAGES and SWAP_FLAG_DISCARD_ONCE
new flags to allow more flexibe swap discard policies being flagged
through swapon(8).  The default behavior is to keep both single-time, or
batched, area discards (SWAP_FLAG_DISCARD_ONCE) and fine-grained discards
for page-clusters (SWAP_FLAG_DISCARD_PAGES) enabled, in order to keep
consistentcy with older kernel behavior, as well as maintain compatibility
with older swapon(8).  However, through the new introduced flags the best
suitable discard policy can be selected accordingly to any given swap
device constraint.

[akpm@linux-foundation.org: tweak comments]
Signed-off-by: NRafael Aquini <aquini@redhat.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Karel Zak <kzak@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently the per cpu counter's batch size for memory accounting is
configured as twice the number of cpus in the system.  However, for
system with very large memory, it is more appropriate to make it
proportional to the memory size per cpu in the system.

For example, for a x86_64 system with 64 cpus and 128 GB of memory, the
batch size is only 2*64 pages (0.5 MB).  So any memory accounting
changes of more than 0.5MB will overflow the per cpu counter into the
global counter.  Instead, for the new scheme, the batch size is
configured to be 0.4% of the memory/cpu = 8MB (128 GB/64 /256), which is
more inline with the memory size.

I've done a repeated brk test of 800KB (from will-it-scale test suite)
with 80 concurrent processes on a 4 socket Westmere machine with a total
of 40 cores.  Without the patch, about 80% of cpu is spent on spin-lock
contention within the vm_committed_as counter.  With the patch, there's
a 73x speedup on the benchmark and the lock contention drops off almost
entirely.

[akpm@linux-foundation.org: fix section mismatch]
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

hugetlb_prefault() is not used any more, this patch removes it.
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NMichal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

get_pageblock_flags and set_pageblock_flags are not used any more, this
patch removes them.
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NMichal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Similar to __pagevec_lru_add, this patch removes the LRU parameter from
__lru_cache_add and lru_cache_add_lru as the caller does not control the
exact LRU the page gets added to.  lru_cache_add_lru gets renamed to
lru_cache_add the name is silly without the lru parameter.  With the
parameter removed, it is required that the caller indicate if they want
the page added to the active or inactive list by setting or clearing
PageActive respectively.

[akpm@linux-foundation.org: Suggested the patch]
[gang.chen@asianux.com: fix used-unintialized warning]
Signed-off-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com>
Cc: Andrew Perepechko <anserper@ya.ru>
Cc: Robin Dong <sanbai@taobao.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Bernd Schubert <bernd.schubert@fastmail.fm>
Cc: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that the LRU to add a page to is decided at LRU-add time, remove the
misleading lru parameter from __pagevec_lru_add.  A consequence of this
is that the pagevec_lru_add_file, pagevec_lru_add_anon and similar
helpers are misleading as the caller no longer has direct control over
what LRU the page is added to.  Unused helpers are removed by this patch
and existing users of pagevec_lru_add_file() are converted to use
lru_cache_add_file() directly and use the per-cpu pagevecs instead of
creating their own pagevec.
Signed-off-by: NMel Gorman <mgorman@suse.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NRik van Riel <riel@redhat.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com>
Cc: Andrew Perepechko <anserper@ya.ru>
Cc: Robin Dong <sanbai@taobao.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Bernd Schubert <bernd.schubert@fastmail.fm>
Cc: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Andrew Perepechko reported a problem whereby pages are being prematurely
evicted as the mark_page_accessed() hint is ignored for pages that are
currently on a pagevec --
http://www.spinics.net/lists/linux-ext4/msg37340.html .

Alexey Lyahkov and Robin Dong have also reported problems recently that
could be due to hot pages reaching the end of the inactive list too
quickly and be reclaimed.

Rather than addressing this on a per-filesystem basis, this series aims
to fix the mark_page_accessed() interface by deferring what LRU a page
is added to pagevec drain time and allowing mark_page_accessed() to call
SetPageActive on a pagevec page.

Patch 1 adds two tracepoints for LRU page activation and insertion. Using
	these processes it's possible to build a model of pages in the
	LRU that can be processed offline.

Patch 2 defers making the decision on what LRU to add a page to until when
	the pagevec is drained.

Patch 3 searches the local pagevec for pages to mark PageActive on
	mark_page_accessed. The changelog explains why only the local
	pagevec is examined.

Patches 4 and 5 tidy up the API.

postmark, a dd-based test and fs-mark both single and threaded mode were
run but none of them showed any performance degradation or gain as a
result of the patch.

Using patch 1, I built a *very* basic model of the LRU to examine
offline what the average age of different page types on the LRU were in
milliseconds.  Of course, capturing the trace distorts the test as it's
written to local disk but it does not matter for the purposes of this
test.  The average age of pages in milliseconds were

				    vanilla deferdrain
Average age mapped anon:               1454       1250
Average age mapped file:             127841     155552
Average age unmapped anon:               85        235
Average age unmapped file:            73633      38884
Average age unmapped buffers:         74054     116155

The LRU activity was mostly files which you'd expect for a dd-based
workload.  Note that the average age of buffer pages is increased by the
series and it is expected this is due to the fact that the buffer pages
are now getting added to the active list when drained from the pagevecs.
Note that the average age of the unmapped file data is decreased as they
are still added to the inactive list and are reclaimed before the
buffers.

There is no guarantee this is a universal win for all workloads and it
would be nice if the filesystem people gave some thought as to whether
this decision is generally a win or a loss.

This patch:

Using these tracepoints it is possible to model LRU activity and the
average residency of pages of different types.  This can be used to
debug problems related to premature reclaim of pages of particular
types.
Signed-off-by: NMel Gorman <mgorman@suse.de>
Reviewed-by: NRik van Riel <riel@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexey Lyahkov <alexey.lyashkov@gmail.com>
Cc: Andrew Perepechko <anserper@ya.ru>
Cc: Robin Dong <sanbai@taobao.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Bernd Schubert <bernd.schubert@fastmail.fm>
Cc: David Howells <dhowells@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We want to allocate ELF note segment buffer on the 2nd kernel in vmalloc
space and remap it to user-space in order to reduce the risk that memory
allocation fails on system with huge number of CPUs and so with huge ELF
note segment that exceeds 11-order block size.

Although there's already remap_vmalloc_range for the purpose of
remapping vmalloc memory to user-space, we need to specify user-space
range via vma.
 Mmap on /proc/vmcore needs to remap range across multiple objects, so
the interface that requires vma to cover full range is problematic.

This patch introduces remap_vmalloc_range_partial that receives user-space
range as a pair of base address and size and can be used for mmap on
/proc/vmcore case.

remap_vmalloc_range is rewritten using remap_vmalloc_range_partial.

[akpm@linux-foundation.org: use PAGE_ALIGNED()]
Signed-off-by: NHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To test whether an address is aligned to PAGE_SIZE.

Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NCody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NCody P Schafer <cody@linux.vnet.ibm.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Page reclaim keeps track of dirty and under writeback pages and uses it
to determine if wait_iff_congested() should stall or if kswapd should
begin writing back pages.  This fails to account for buffer pages that
can be under writeback but not PageWriteback which is the case for
filesystems like ext3 ordered mode.  Furthermore, PageDirty buffer pages
can have all the buffers clean and writepage does no IO so it should not
be accounted as congested.

This patch adds an address_space operation that filesystems may
optionally use to check if a page is really dirty or really under
writeback.  An implementation is provided for for buffer_heads is added
and used for block operations and ext3 in ordered mode.  By default the
page flags are obeyed.

Credit goes to Jan Kara for identifying that the page flags alone are
not sufficient for ext3 and sanity checking a number of ideas on how the
problem could be addressed.
Signed-off-by: NMel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Zlatko Calusic <zcalusic@bitsync.net>
Cc: dormando <dormando@rydia.net>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>