Error value got overwritten instantly.
Signed-off-by: NNicolas Kaiser <nikai@nikai.net>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

printk.h uses va_list but doesn't include stdarg.h.  Hence printk.h is
unusable unless its includer has already included kernel.h (which includes
stdarg.h).

Remove the dependency by including stdarg.h in printk.h
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The early console implementations are the same all over the place.  Move
the print function to kernel/printk and get rid of the copies.

[akpm@linux-foundation.org: arch/mips/kernel/early_printk.c needs kernel.h for va_list]
[paul.gortmaker@windriver.com: sh4: make the bios early console support depend on EARLY_PRINTK]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Richard Weinberger <richard@nod.at>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Tested-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 7ff9554b ("printk: convert byte-buffer to variable-length
record buffer") removed start and end parameters from
call_console_drivers, but those parameters still exist in
include/trace/events/printk.h.

Without start and end parameters handling, printk tracing became more
simple as: trace_console(text, len);
Signed-off-by: Nzhangwei(Jovi) <jovi.zhangwei@huawei.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__builtin_object_size is known to be broken on gcc 4.6+.
See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48880 for details.

This causes unnecssary build warnings and errors such as

  In function 'copy_from_user', inlined from 'sb16_copy_from_user'
	at sound/oss/sb_audio.c:878:22:
  arch/x86/include/asm/uaccess_32.h:211:26: error: call to 'copy_from_user_overflow'
	declared with attribute error: copy_from_user() buffer size is not provably correct
  make[3]: [sound/oss/sb_audio.o] Error 1 (ignored)

Disable it where broken.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch depends on "genalloc: add devres support, allow to find a
managed pool by device", which provides the of_get_named_gen_pool and
dev_get_gen_pool functions.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NJavier Martin <javier.martin@vista-silicon.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Shijie <shijie8@gmail.com>
Cc: Matt Porter <mporter@ti.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This driver requests and remaps a memory region as configured in the
device tree.  It serves memory from this region via the genalloc API.  It
optionally enables the SRAM clock.

Other drivers can retrieve the genalloc pool from a phandle pointing to
this drivers' device node in the device tree.

The allocation granularity is hard-coded to 32 bytes for now, to make the
SRAM driver useful for the 6502 remoteproc driver.  There is overhead for
bigger SRAMs, where only a much coarser allocation granularity is needed:
At 32 bytes minimum allocation size, a 256 KiB SRAM needs a 1 KiB bitmap
to track allocations.

[akpm@linux-foundation.org: fix Kconfig text, make sram_init static]
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Tested-by: NMichal Simek <monstr@monstr.eu>
Cc: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Shijie <shijie8@gmail.com>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Matt Porter <mporter@ti.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds three exported functions to lib/genalloc.c:
devm_gen_pool_create, dev_get_gen_pool, and of_get_named_gen_pool.

devm_gen_pool_create is a managed version of gen_pool_create that keeps
track of the pool via devres and allows the management code to
automatically destroy it after device removal.

dev_get_gen_pool retrieves the gen_pool for a given device, if it was
created with devm_gen_pool_create, using devres_find.

of_get_named_gen_pool retrieves the gen_pool for a given device node and
property name, where the property must contain a phandle pointing to a
platform device node.  The corresponding platform device is then fed into
dev_get_gen_pool and the resulting gen_pool is returned.

[akpm@linux-foundation.org: make the of_get_named_gen_pool() stub static, fixing a zillion link errors]
[akpm@linux-foundation.org: squish "struct device declared inside parameter list" warning]
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Tested-by: NMichal Simek <monstr@monstr.eu>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Matt Porter <mporter@ti.com>
Cc: Dong Aisheng <dong.aisheng@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Javier Martin <javier.martin@vista-silicon.com>
Cc: Huang Shijie <shijie8@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Return a negative error code from the error handling case instead of 0, as
returned elsewhere in this function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The memcg is not referenced, so it can be destroyed at anytime right
after we exit rcu read section, so it's not safe to access it.

To fix this, we call css_tryget() to get a reference while we're still
in rcu read section.

This also removes a bogus comment above __memcg_create_cache_enqueue().
Signed-off-by: NLi Zefan <lizefan@huawei.com>
Acked-by: NGlauber Costa <glommer@parallels.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When hot removing memory presented at boot time, following messages are shown:

  kernel BUG at mm/slub.c:3409!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: ebtable_nat ebtables xt_CHECKSUM iptable_mangle bridge stp llc ipmi_devintf ipmi_msghandler sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc vfat fat dm_mirror dm_region_hash dm_log dm_mod vhost_net macvtap macvlan tun uinput iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode pcspkr sg i2c_i801 lpc_ich mfd_core igb i2c_algo_bit i2c_core e1000e ptp pps_core tpm_infineon ioatdma dca sr_mod cdrom sd_mod crc_t10dif usb_storage megaraid_sas lpfc scsi_transport_fc scsi_tgt scsi_mod
  CPU 0
  Pid: 5091, comm: kworker/0:2 Tainted: G        W    3.9.0-rc6+ #15
  RIP: kfree+0x232/0x240
  Process kworker/0:2 (pid: 5091, threadinfo ffff88084678c000, task ffff88083928ca80)
  Call Trace:
    __release_region+0xd4/0xe0
    __remove_pages+0x52/0x110
    arch_remove_memory+0x89/0xd0
    remove_memory+0xc4/0x100
    acpi_memory_device_remove+0x6d/0xb1
    acpi_device_remove+0x89/0xab
    __device_release_driver+0x7c/0xf0
    device_release_driver+0x2f/0x50
    acpi_bus_device_detach+0x6c/0x70
    acpi_ns_walk_namespace+0x11a/0x250
    acpi_walk_namespace+0xee/0x137
    acpi_bus_trim+0x33/0x7a
    acpi_bus_hot_remove_device+0xc4/0x1a1
    acpi_os_execute_deferred+0x27/0x34
    process_one_work+0x1f7/0x590
    worker_thread+0x11a/0x370
    kthread+0xee/0x100
    ret_from_fork+0x7c/0xb0
  RIP  [<ffffffff811c41d2>] kfree+0x232/0x240
   RSP <ffff88084678d968>

The reason why the messages are shown is to release a resource
structure, allocated by bootmem, by kfree().  So when we release a
resource structure, we should check whether it is allocated by bootmem
or not.

But even if we know a resource structure is allocated by bootmem, we
cannot release it since SLxB cannot treat it.  So for reusing a resource
structure, this patch remembers it by using bootmem_resource as follows:

When releasing a resource structure by free_resource(), free_resource()
checks whether the resource structure is allocated by bootmem or not.
If it is allocated by bootmem, free_resource() adds it to
bootmem_resource.  If it is not allocated by bootmem, free_resource()
release it by kfree().

And when getting a new resource structure by get_resource(),
get_resource() checks whether bootmem_resource has released resource
structures or not.  If there is a released resource structure,
get_resource() returns it.  If there is not a releaed resource
structure, get_resource() returns new resource structure allocated by
kzalloc().

[akpm@linux-foundation.org: s/get_resource/alloc_resource/]
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Ram Pai <linuxram@us.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>

There are times when HIGHMEM is enabled, but we don't prefer
CONFIG_BOUNCE to be enabled.  CONFIG_BOUNCE can reduce the block device
throughput, and this is not ideal for machines where we don't gain much
by enabling it.  So provide an option to deselect CONFIG_BOUNCE.  The
observation was made while measuring eMMC throughput using iozone on an
ARM device with 1GB RAM.
Signed-off-by: NVinayak Menon <vinayakm.list@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Randy Dunlap <rdunlap@infradead.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>

Currently, we do memset() before reserving the area.  This may not cause
any problem, but it is somewhat weird.  So change execution order.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove unused argument and make function static, because there is no user
outside of nobootmem.c
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bh allocation uses kmem_cache_zalloc() so we needn't call
'init_buffer(bh, NULL, NULL)' and perform other set-zero-operations.
Signed-off-by: NJianpeng Ma <majianpeng@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When booting x86 system contains memoryless node, node numbers of CPUs
on memoryless node were changed to nearest online node number by
init_cpu_to_node() because the node is not online.

In my system, node numbers of cpu#30-44 and 75-89 were changed from 2 to
0 as follows:

  $ numactl --hardware
  available: 2 nodes (0-1)
  node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 30 31 32 33 34 35 36 37 38 39 40
  41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 75 76 77 78 79 80 81 82
  83 84 85 86 87 88 89
  node 0 size: 32394 MB
  node 0 free: 27898 MB
  node 1 cpus: 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 60 61 62 63 64 65 66
  67 68 69 70 71 72 73 74
  node 1 size: 32768 MB
  node 1 free: 30335 MB

If we hot add memory to memoryless node and offine/online all CPUs on
the node, node numbers of these CPUs are changed to correct node numbers
by srat_detect_node() because the node become online.

In this case, node numbers of cpu#30-44 and 75-89 were changed from 0 to
2 in my system as follows:

  $ numactl --hardware
  available: 3 nodes (0-2)
  node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 45 46 47 48 49 50 51 52 53 54 55
  56 57 58 59
  node 0 size: 32394 MB
  node 0 free: 27218 MB
  node 1 cpus: 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 60 61 62 63 64 65 66
  67 68 69 70 71 72 73 74
  node 1 size: 32768 MB
  node 1 free: 30014 MB
  node 2 cpus: 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 75 76 77 78 79 80 81
  82 83 84 85 86 87 88 89
  node 2 size: 16384 MB
  node 2 free: 16384 MB

But "cpu to node" and "node to cpu" links were not changed as follows:

  $ ls /sys/devices/system/cpu/cpu30/|grep node
  node0
  $ ls /sys/devices/system/node/node0/|grep cpu30
  cpu30

"numactl --hardware" shows that cpu30 belongs to node 2.  But sysfs
links does not change.

This patch changes "cpu to node" and "node to cpu" links when node
number changed by onlining CPU.
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

PFN_PHYS() is a phys_addr_t, which can be u32 or u64.
Fix the build warning when phys_addr_t is u32.

  mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 2 has type 'unsigned int' [-Wformat]:  => 1685:3
  mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'unsigned int' [-Wformat]:  => 1685:3
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As pointed out by Andrew Morton, the swap-over-NFS writeback is not
setting PageWriteback before it is queued for direct IO.  While swap
pages do not participate in BDI or process dirty accounting and the IO
is synchronous, the writeback bit is still required and not setting it
in this case was an oversight.  swapoff depends on the page writeback to
synchronoise all pending writes on a swap page before it is reused.
Swapcache freeing and reuse depend on checking the PageWriteback under
lock to ensure the page is safe to reuse.

Direct IO handlers and the direct IO handler for NFS do not deal with
PageWriteback as they are synchronous writes.  In the case of NFS, it
schedules pages (or a page in the case of swap) for IO and then waits
synchronously for IO to complete in nfs_direct_write().  It is
recognised that this is a slowdown from normal swap handling which is
asynchronous and uses a completion handler.  Shoving PageWriteback
handling down into direct IO handlers looks like a bad fit to handle the
swap case although it may have to be dealt with some day if swap is
converted to use direct IO in general and bmap is finally done away
with.  At that point it will be necessary to refit asynchronous direct
IO with completion handlers onto the swap subsystem.

As swapcache currently depends on PageWriteback to protect against
races, this patch sets PageWriteback under the page lock before queueing
it for direct IO.  It is cleared when the direct IO handler returns.  IO
errors are treated similarly to the direct-to-bio case except PageError
is not set as in the case of swap-over-NFS, it is likely to be a
transient error.

It was asked what prevents such a page being reclaimed in parallel.
With this patch applied, such a page will now be skipped (most of the
time) or blocked until the writeback completes.  Reclaim checks
PageWriteback under the page lock before calling try_to_free_swap and
the page lock should prevent the page being requeued for IO before it is
freed.

This and Jerome's related patch should considered for -stable as far
back as 3.6 when swap-over-NFS was introduced.

[akpm@linux-foundation.org: use pr_err_ratelimited()]
[akpm@linux-foundation.org: remove hopefully-unneeded cast in printk]
Signed-off-by: NMel Gorman <mgorman@suse.de>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[3.6+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 62c230bc ("mm: add support for a filesystem to activate
swap files and use direct_IO for writing swap pages"), swap_writepage()
calls direct_IO on swap files.  However, in that case the page isn't
redirtied if I/O fails, and is therefore handled afterwards as if it has
been successfully written to the swap file, leading to memory corruption
when the page is eventually swapped back in.

This patch sets the page dirty when direct_IO() fails.  It fixes a
memory corruption that happened while using swap-over-NFS.
Signed-off-by: NJerome Marchand <jmarchan@redhat.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[3.6+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A memcg may livelock when oom if the process that grabs the hierarchy's
oom lock is never the first process with PF_EXITING set in the memcg's
task iteration.

The oom killer, both global and memcg, will defer if it finds an
eligible process that is in the process of exiting and it is not being
ptraced.  The idea is to allow it to exit without using memory reserves
before needlessly killing another process.

This normally works fine except in the memcg case with a large number of
threads attached to the oom memcg.  In this case, the memcg oom killer
only gets called for the process that grabs the hierarchy's oom lock;
all others end up blocked on the memcg's oom waitqueue.  Thus, if the
process that grabs the hierarchy's oom lock is never the first
PF_EXITING process in the memcg's task iteration, the oom killer is
constantly deferred without anything making progress.

The fix is to give PF_EXITING processes access to memory reserves so
that we've marked them as oom killed without any iteration.  This allows
__mem_cgroup_try_charge() to succeed so that the process may exit.  This
makes the memcg oom killer exemption for TIF_MEMDIE tasks, now
immediately granted for processes with pending SIGKILLs and those in the
exit path, to be equivalent to what is done for the global oom killer.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current implementation of huge zero page uses pfn value 0 to indicate
that the page hasn't allocated yet.  It assumes that buddy page
allocator can't return page with pfn == 0.

Let's rework the code to store 'struct page *' of huge zero page, not
its pfn.  This way we can avoid the weak assumption.

[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
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>

This might cause a use-after-free bug.
Signed-off-by: NLi Zefan <lizefan@huawei.com>
Cc: Glauber Costa <glommer@parallels.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are two convenient ways to report errors to userspace

1) retun error to original syscall for example write(2)
2) mark mapping with error flag and return it on later fsync(2)

Second one is broken if (mapping->nrpages == 0) This is real-life
situation because after error pages are likey to be truncated or
invalidated.

We have to return an error regardless to number of pages in the mapping.

#Original testcase: git@github.com:dmonakhov/xfstests.git
MOUNT_OPTIONS="-b1024"
./check shared/305
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no comment for parameter nid of memblock_insert_region().
This patch adds comment for it.
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

nr_pages is not used in pages_correctly_reserved().
So remove it.
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: NWang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: NWen Congyang <wency@cn.fujitsu.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When hot removing memory, a firmware_map_entry which has memory range of
the memory is released by release_firmware_map_entry().  If the entry is
allocated by bootmem, release_firmware_map_entry() adds the entry to
map_entires_bootmem list when firmware_map_find_entry() finds the entry
from map_entries list.  But firmware_map_find_entry never find the entry
sicne map_entires list does not have the entry.  So the entry just
leaks.

Here are steps of leaking firmware_map_entry:
firmware_map_remove()
-> firmware_map_find_entry()
   Find released entry from map_entries list
-> firmware_map_remove_entry()
   Delete the entry from map_entries list
-> remove_sysfs_fw_map_entry()
   ...
   -> release_firmware_map_entry()
      -> firmware_map_find_entry()
         Find the entry from map_entries list but the entry has been
         deleted from map_entries list. So the entry is not added
         to map_entries_bootmem. Thus the entry leaks

release_firmware_map_entry() should not call firmware_map_find_entry()
since releaed entry has been deleted from map_entries list.  So the
patch delete firmware_map_find_entry() from releae_firmware_map_entry()
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NTang Chen <tangchen@cn.fujitsu.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Greg KH <greg@kroah.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>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In page reclaim, huge page is split.  split_huge_page() adds tail pages
to LRU list.  Since we are reclaiming a huge page, it's better we
reclaim all subpages of the huge page instead of just the head page.
This patch adds split tail pages to shrink page list so the tail pages
can be reclaimed soon.

Before this patch, run a swap workload:
  thp_fault_alloc 3492
  thp_fault_fallback 608
  thp_collapse_alloc 6
  thp_collapse_alloc_failed 0
  thp_split 916

With this patch:
  thp_fault_alloc 4085
  thp_fault_fallback 16
  thp_collapse_alloc 90
  thp_collapse_alloc_failed 0
  thp_split 1272

fallback allocation is reduced a lot.

[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]
Signed-off-by: NShaohua Li <shli@fusionio.com>
Acked-by: NRik van Riel <riel@redhat.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To prevent flooding the swap device with writebacks, frontswap backends
need to count and limit the number of outstanding writebacks.  The
incrementing of the counter can be done before the call to
__swap_writepage().  However, the caller must receive a notification
when the writeback completes in order to decrement the counter.

To achieve this functionality, this patch modifies __swap_writepage() to
take the bio completion callback function as an argument.

end_swap_bio_write(), the normal bio completion function, is also made
non-static so that code doing the accounting can call it after the
accounting is done.

There should be no behavioural change to existing code.
Signed-off-by: NSeth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: NBob Liu <bob.liu@oracle.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NDan Magenheimer <dan.magenheimer@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

swap_writepage() is currently where frontswap hooks into the swap write
path to capture pages with the frontswap_store() function.  However, if
a frontswap backend wants to "resume" the writeback of a page to the
swap device, it can't call swap_writepage() as the page will simply
reenter the backend.

This patch separates swap_writepage() into a top and bottom half, the
bottom half named __swap_writepage() to allow a frontswap backend, like
zswap, to resume writeback beyond the frontswap_store() hook.

__add_to_swap_cache() is also made non-static so that the page for which
writeback is to be resumed can be added to the swap cache.
Signed-off-by: NSeth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: NBob Liu <bob.liu@oracle.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Reviewed-by: NDan Magenheimer <dan.magenheimer@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a corner case for MAP_FIXED when requested mapping length is larger
than rlimit for virtual memory.  In such case any overlapping mappings
are unmapped before we check for the limit and return ENOMEM.

The check is moved before the loop that unmaps overlapping parts of
existing mappings.  When we are about to hit the limit (currently mapped
pages + len > limit) we scan for overlapping pages and check again
accounting for them.

This fixes situation when userspace program expects that the previous
mappings are preserved after the mmap() syscall has returned with error.
(POSIX clearly states that successfull mapping shall replace any
previous mappings.)

This corner case was found and can be tested with LTP testcase:

testcases/open_posix_testsuite/conformance/interfaces/mmap/24-2.c

In this case the mmap, which is clearly over current limit, unmaps
dynamic libraries and the testcase segfaults right after returning into
userspace.

I've also looked at the second instance of the unmapping loop in the
do_brk().  The do_brk() is called from brk() syscall and from vm_brk().
The brk() syscall checks for overlapping mappings and bails out when
there are any (so it can't be triggered from the brk syscall).  The
vm_brk() is called only from binmft handlers so it shouldn't be
triggered unless binmft handler created overlapping mappings.
Signed-off-by: NCyril Hrubis <chrubis@suse.cz>
Reviewed-by: NMel Gorman <mgorman@suse.de>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With this patch userland applications that want to maintain the
interactivity/memory allocation cost can use the pressure level
notifications.  The levels are defined like this:

The "low" level means that the system is reclaiming memory for new
allocations.  Monitoring this reclaiming activity might be useful for
maintaining cache level.  Upon notification, the program (typically
"Activity Manager") might analyze vmstat and act in advance (i.e.
prematurely shutdown unimportant services).

The "medium" level means that the system is experiencing medium memory
pressure, the system might be making swap, paging out active file
caches, etc.  Upon this event applications may decide to further analyze
vmstat/zoneinfo/memcg or internal memory usage statistics and free any
resources that can be easily reconstructed or re-read from a disk.

The "critical" level means that the system is actively thrashing, it is
about to out of memory (OOM) or even the in-kernel OOM killer is on its
way to trigger.  Applications should do whatever they can to help the
system.  It might be too late to consult with vmstat or any other
statistics, so it's advisable to take an immediate action.

The events are propagated upward until the event is handled, i.e.  the
events are not pass-through.  Here is what this means: for example you
have three cgroups: A->B->C.  Now you set up an event listener on
cgroups A, B and C, and suppose group C experiences some pressure.  In
this situation, only group C will receive the notification, i.e.  groups
A and B will not receive it.  This is done to avoid excessive
"broadcasting" of messages, which disturbs the system and which is
especially bad if we are low on memory or thrashing.  So, organize the
cgroups wisely, or propagate the events manually (or, ask us to
implement the pass-through events, explaining why would you need them.)

Performance wise, the memory pressure notifications feature itself is
lightweight and does not require much of bookkeeping, in contrast to the
rest of memcg features.  Unfortunately, as of current memcg
implementation, pages accounting is an inseparable part and cannot be
turned off.  The good news is that there are some efforts[1] to improve
the situation; plus, implementing the same, fully API-compatible[2]
interface for CONFIG_MEMCG=n case (e.g.  embedded) is also a viable
option, so it will not require any changes on the userland side.

[1] http://permalink.gmane.org/gmane.linux.kernel.cgroups/6291
[2] http://lkml.org/lkml/2013/2/21/454

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix CONFIG_CGROPUPS=n warnings]
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: NKirill A. Shutemov <kirill@shutemov.name>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Leonid Moiseichuk <leonid.moiseichuk@nokia.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In madvise(), there doesn't seem to be any reason for taking the
&current->mm->mmap_sem before start and len_in have been validated.
Incidentally, this removes the need for the out: label.

[akpm@linux-foundation.org: s/out_plug/out/, per David]
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>

__remove_pages() is only necessary for CONFIG_MEMORY_HOTREMOVE.  PowerPC
pseries will return -EOPNOTSUPP if unsupported.

Adding an #ifdef causes several other functions it depends on to also
become unnecessary, which saves in .text when disabled (it's disabled in
most defconfigs besides powerpc, including x86).  remove_memory_block()
becomes static since it is not referenced outside of
drivers/base/memory.c.

Build tested on x86 and powerpc with CONFIG_MEMORY_HOTREMOVE both enabled
and disabled.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change __remove_pages() to call release_mem_region_adjustable().  This
allows a requested memory range to be released from the iomem_resource
table even if it does not match exactly to an resource entry but still
fits into.  The resource entries initialized at bootup usually cover the
whole contiguous memory ranges and may not necessarily match with the
size of memory hot-delete requests.

If release_mem_region_adjustable() failed, __remove_pages() emits a
warning message and continues to proceed as it was the case with
release_mem_region().  release_mem_region(), which is defined to
__release_region(), emits a warning message and returns no error since a
void function.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Reviewed-by : Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: T Makphaibulchoke <tmac@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add release_mem_region_adjustable(), which releases a requested region
from a currently busy memory resource.  This interface adjusts the
matched memory resource accordingly even if the requested region does
not match exactly but still fits into.

This new interface is intended for memory hot-delete.  During bootup,
memory resources are inserted from the boot descriptor table, such as
EFI Memory Table and e820.  Each memory resource entry usually covers
the whole contigous memory range.  Memory hot-delete request, on the
other hand, may target to a particular range of memory resource, and its
size can be much smaller than the whole contiguous memory.  Since the
existing release interfaces like __release_region() require a requested
region to be exactly matched to a resource entry, they do not allow a
partial resource to be released.

This new interface is restrictive (i.e.  release under certain
conditions), which is consistent with other release interfaces,
__release_region() and __release_resource().  Additional release
conditions, such as an overlapping region to a resource entry, can be
supported after they are confirmed as valid cases.

There is no change to the existing interfaces since their restriction is
valid for I/O resources.

[akpm@linux-foundation.org: use GFP_ATOMIC under write_lock()]
[akpm@linux-foundation.org: switch back to GFP_KERNEL, less buggily]
[akpm@linux-foundation.org: remove unneeded and wrong kfree(), per Toshi]
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Reviewed-by : Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Reviewed-by: NRam Pai <linuxram@us.ibm.com>
Cc: T Makphaibulchoke <tmac@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add __adjust_resource(), which is called by adjust_resource() internally
after the resource_lock is held.  There is no interface change to
adjust_resource().  This change allows other functions to call
__adjust_resource() internally while the resource_lock is held.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Reviewed-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: T Makphaibulchoke <tmac@hp.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The comment over migrate_pages() looks quite weird, and makes it hard to
grasp what it is trying to say.  Rewrite it more comprehensibly.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently the memory barrier in __do_huge_pmd_anonymous_page doesn't
work.  Because lru_cache_add_lru uses pagevec so it could miss spinlock
easily so above rule was broken so user might see inconsistent data.

I was not first person who pointed out the problem.  Mel and Peter
pointed out a few months ago and Peter pointed out further that even
spin_lock/unlock can't make sure of it:

  http://marc.info/?t=134333512700004

	In particular:

        	*A = a;
        	LOCK
        	UNLOCK
        	*B = b;

	may occur as:

        	LOCK, STORE *B, STORE *A, UNLOCK

At last, Hugh pointed out that even we don't need memory barrier in
there because __SetPageUpdate already have done it from Nick's commit
0ed361de ("mm: fix PageUptodate data race") explicitly.

So this patch fixes comment on THP and adds same comment for
do_anonymous_page, too because everybody except Hugh was missing that.
It means we need a comment about that.
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_HOTPLUG is going away as an option, cleanup CONFIG_HOTPLUG
ifdefs in mm files.
Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>