Fixes the following boot-time warning:

  [    0.000000] ------------[ cut here ]------------
  [    0.000000] WARNING: at kernel/smp.c:369 smp_call_function_many+0x56/0x1bc()
  [    0.000000] Hardware name:
  [    0.000000] Modules linked in:
  [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30 #492
  [    0.000000] Call Trace:
  [    0.000000]  [<ffffffff8149e021>] ? _spin_unlock+0x4f/0x5c
  [    0.000000]  [<ffffffff8108f11b>] ? smp_call_function_many+0x56/0x1bc
  [    0.000000]  [<ffffffff81061764>] warn_slowpath_common+0x7c/0xa9
  [    0.000000]  [<ffffffff810617a5>] warn_slowpath_null+0x14/0x16
  [    0.000000]  [<ffffffff8108f11b>] smp_call_function_many+0x56/0x1bc
  [    0.000000]  [<ffffffff810f3e00>] ? do_ccupdate_local+0x0/0x54
  [    0.000000]  [<ffffffff810f3e00>] ? do_ccupdate_local+0x0/0x54
  [    0.000000]  [<ffffffff8108f2be>] smp_call_function+0x3d/0x68
  [    0.000000]  [<ffffffff810f3e00>] ? do_ccupdate_local+0x0/0x54
  [    0.000000]  [<ffffffff81066fd8>] on_each_cpu+0x31/0x7c
  [    0.000000]  [<ffffffff810f64f5>] do_tune_cpucache+0x119/0x454
  [    0.000000]  [<ffffffff81087080>] ? lockdep_init_map+0x94/0x10b
  [    0.000000]  [<ffffffff818133b0>] ? kmem_cache_init+0x421/0x593
  [    0.000000]  [<ffffffff810f69cf>] enable_cpucache+0x68/0xad
  [    0.000000]  [<ffffffff818133c3>] kmem_cache_init+0x434/0x593
  [    0.000000]  [<ffffffff8180987c>] ? mem_init+0x156/0x161
  [    0.000000]  [<ffffffff817f8aae>] start_kernel+0x1cc/0x3b9
  [    0.000000]  [<ffffffff817f829a>] x86_64_start_reservations+0xaa/0xae
  [    0.000000]  [<ffffffff817f837f>] x86_64_start_kernel+0xe1/0xe8
  [    0.000000] ---[ end trace 4eaa2a86a8e2da22 ]---

Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

As explained by Benjamin Herrenschmidt:

  Oh and btw, your patch alone doesn't fix powerpc, because it's missing
  a whole bunch of GFP_KERNEL's in the arch code... You would have to
  grep the entire kernel for things that check slab_is_available() and
  even then you'll be missing some.

  For example, slab_is_available() didn't always exist, and so in the
  early days on powerpc, we used a mem_init_done global that is set form
  mem_init() (not perfect but works in practice). And we still have code
  using that to do the test.

Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators
in early boot code to avoid enabling interrupts.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Fixes the following warning during bootup when compiling with CONFIG_SLAB:

  [    0.000000] ------------[ cut here ]------------
  [    0.000000] WARNING: at kernel/lockdep.c:2282 lockdep_trace_alloc+0x91/0xb9()
  [    0.000000] Hardware name:
  [    0.000000] Modules linked in:
  [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30 #491
  [    0.000000] Call Trace:
  [    0.000000]  [<ffffffff81087d84>] ? lockdep_trace_alloc+0x91/0xb9
  [    0.000000]  [<ffffffff81061764>] warn_slowpath_common+0x7c/0xa9
  [    0.000000]  [<ffffffff810617a5>] warn_slowpath_null+0x14/0x16
  [    0.000000]  [<ffffffff81087d84>] lockdep_trace_alloc+0x91/0xb9
  [    0.000000]  [<ffffffff810f5b03>] kmem_cache_alloc_node_notrace+0x26/0xdf
  [    0.000000]  [<ffffffff81487f4e>] ? setup_cpu_cache+0x7e/0x210
  [    0.000000]  [<ffffffff81487fe3>] setup_cpu_cache+0x113/0x210
  [    0.000000]  [<ffffffff810f73ff>] kmem_cache_create+0x409/0x486
  [    0.000000]  [<ffffffff818131c1>] kmem_cache_init+0x232/0x593
  [    0.000000]  [<ffffffff8180987c>] ? mem_init+0x156/0x161
  [    0.000000]  [<ffffffff817f8aae>] start_kernel+0x1cc/0x3b9
  [    0.000000]  [<ffffffff817f829a>] x86_64_start_reservations+0xaa/0xae
  [    0.000000]  [<ffffffff817f837f>] x86_64_start_kernel+0xe1/0xe8
  [    0.000000] ---[ end trace 4eaa2a86a8e2da22 ]---
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Now, SLAB is configured in very early stage and it can be used in
init routine now.

But replacing alloc_bootmem() in FLAT/DISCONTIGMEM's page_cgroup()
initialization breaks the allocation, now.
(Works well in SPARSEMEM case...it supports MEMORY_HOTPLUG and
 size of page_cgroup is in reasonable size (< 1 << MAX_ORDER.)

This patch revive FLATMEM+memory cgroup by using alloc_bootmem.

In future,
We stop to support FLATMEM (if no users) or rewrite codes for flatmem
completely.But this will adds more messy codes and overheads.
Reported-by: NLi Zefan <lizf@cn.fujitsu.com>
Tested-by: NLi Zefan <lizf@cn.fujitsu.com>
Tested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

The bootmem allocator is no longer available for page_cgroup_init() because we
set up the kernel slab allocator much earlier now.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

We can call vmalloc_init() after kmem_cache_init() and use kzalloc() instead of
the bootmem allocator when initializing vmalloc data structures.
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NNick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch makes kmalloc() available earlier in the boot sequence so we can get
rid of some bootmem allocations. The bulk of the changes are due to
kmem_cache_init() being called with interrupts disabled which requires some
changes to allocator boostrap code.

Note: 32-bit x86 does WP protect test in mem_init() so we must setup traps
before we call mem_init() during boot as reported by Ingo Molnar:

  We have a hard crash in the WP-protect code:

  [    0.000000] Checking if this processor honours the WP bit even in supervisor mode...BUG: Int 14: CR2 ffcff000
  [    0.000000]      EDI 00000188  ESI 00000ac7  EBP c17eaf9c  ESP c17eaf8c
  [    0.000000]      EBX 000014e0  EDX 0000000e  ECX 01856067  EAX 00000001
  [    0.000000]      err 00000003  EIP c10135b1   CS 00000060  flg 00010002
  [    0.000000] Stack: c17eafa8 c17fd410 c16747bc c17eafc4 c17fd7e5 000011fd f8616000 c18237cc
  [    0.000000]        00099800 c17bb000 c17eafec c17f1668 000001c5 c17f1322 c166e039 c1822bf0
  [    0.000000]        c166e033 c153a014 c18237cc 00020800 c17eaff8 c17f106a 00020800 01ba5003
  [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30-tip-02161-g7a74539-dirty #52203
  [    0.000000] Call Trace:
  [    0.000000]  [<c15357c2>] ? printk+0x14/0x16
  [    0.000000]  [<c10135b1>] ? do_test_wp_bit+0x19/0x23
  [    0.000000]  [<c17fd410>] ? test_wp_bit+0x26/0x64
  [    0.000000]  [<c17fd7e5>] ? mem_init+0x1ba/0x1d8
  [    0.000000]  [<c17f1668>] ? start_kernel+0x164/0x2f7
  [    0.000000]  [<c17f1322>] ? unknown_bootoption+0x0/0x19c
  [    0.000000]  [<c17f106a>] ? __init_begin+0x6a/0x6f
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

If the user requested bootmem allocation on a specific node, we should use
kzalloc_node() for the fallback allocation.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

As a preparation for initializing the slab allocator early, make sure the
bootmem allocator does not crash and burn if someone calls it after slab is up;
otherwise we'd need a flag day for switching to early slab.
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch adds a loadable module that deliberately leaks memory. It
is used for testing various memory leaking scenarios.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch adds the Kconfig.debug and Makefile entries needed for
building kmemleak into the kernel.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The alloc_large_system_hash function is called from various places in
the kernel and it contains pointers to other allocated structures. It
therefore needs to be traced by kmemleak.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch adds the callbacks to kmemleak_(alloc|free) functions from
vmalloc/vfree.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch adds the callbacks to kmemleak_(alloc|free) functions from the
slub allocator.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch adds the callbacks to kmemleak_(alloc|free) functions from the
slob allocator.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMatt Mackall <mpm@selenic.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch adds the callbacks to kmemleak_(alloc|free) functions from
the slab allocator. The patch also adds the SLAB_NOLEAKTRACE flag to
avoid recursive calls to kmemleak when it allocates its own data
structures.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch adds the base support for the kernel memory leak
detector. It traces the memory allocation/freeing in a way similar to
the Boehm's conservative garbage collector, the difference being that
the unreferenced objects are not freed but only shown in
/sys/kernel/debug/kmemleak. Enabling this feature introduces an
overhead to memory allocations.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

With the "security: use mmap_min_addr indepedently of security models"
change, mmap_min_addr is used in common areas, which susbsequently blows
up the nommu build. This stubs in the definition in the nommu case as
well.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

--

 mm/nommu.c |    3 +++
 1 file changed, 3 insertions(+)
Signed-off-by: NJames Morris <jmorris@namei.org>

TRACE_EVENT is a more generic way to define tracepoints. Doing so adds
these new capabilities to this tracepoint:

  - zero-copy and per-cpu splice() tracing
  - binary tracing without printf overhead
  - structured logging records exposed under /debug/tracing/events
  - trace events embedded in function tracer output and other plugins
  - user-defined, per tracepoint filter expressions
  ...

Cons:

  - no dev_t info for the output of plug, unplug_timer and unplug_io events.
    no dev_t info for getrq and sleeprq events if bio == NULL.
    no dev_t info for rq_abort,...,rq_requeue events if rq->rq_disk == NULL.

    This is mainly because we can't get the deivce from a request queue.
    But this may change in the future.

  - A packet command is converted to a string in TP_assign, not TP_print.
    While blktrace do the convertion just before output.

    Since pc requests should be rather rare, this is not a big issue.

  - In blktrace, an event can have 2 different print formats, but a TRACE_EVENT
    has a unique format, which means we have some unused data in a trace entry.

    The overhead is minimized by using __dynamic_array() instead of __array().

I've benchmarked the ioctl blktrace vs the splice based TRACE_EVENT tracing:

      dd                   dd + ioctl blktrace       dd + TRACE_EVENT (splice)
1     7.36s, 42.7 MB/s     7.50s, 42.0 MB/s          7.41s, 42.5 MB/s
2     7.43s, 42.3 MB/s     7.48s, 42.1 MB/s          7.43s, 42.4 MB/s
3     7.38s, 42.6 MB/s     7.45s, 42.2 MB/s          7.41s, 42.5 MB/s

So the overhead of tracing is very small, and no regression when using
those trace events vs blktrace.

And the binary output of TRACE_EVENT is much smaller than blktrace:

 # ls -l -h
 -rw-r--r-- 1 root root 8.8M 06-09 13:24 sda.blktrace.0
 -rw-r--r-- 1 root root 195K 06-09 13:24 sda.blktrace.1
 -rw-r--r-- 1 root root 2.7M 06-09 13:25 trace_splice.out

Following are some comparisons between TRACE_EVENT and blktrace:

plug:
  kjournald-480   [000]   303.084981: block_plug: [kjournald]
  kjournald-480   [000]   303.084981:   8,0    P   N [kjournald]

unplug_io:
  kblockd/0-118   [000]   300.052973: block_unplug_io: [kblockd/0] 1
  kblockd/0-118   [000]   300.052974:   8,0    U   N [kblockd/0] 1

remap:
  kjournald-480   [000]   303.085042: block_remap: 8,0 W 102736992 + 8 <- (8,8) 33384
  kjournald-480   [000]   303.085043:   8,0    A   W 102736992 + 8 <- (8,8) 33384

bio_backmerge:
  kjournald-480   [000]   303.085086: block_bio_backmerge: 8,0 W 102737032 + 8 [kjournald]
  kjournald-480   [000]   303.085086:   8,0    M   W 102737032 + 8 [kjournald]

getrq:
  kjournald-480   [000]   303.084974: block_getrq: 8,0 W 102736984 + 8 [kjournald]
  kjournald-480   [000]   303.084975:   8,0    G   W 102736984 + 8 [kjournald]

  bash-2066  [001]  1072.953770:   8,0    G   N [bash]
  bash-2066  [001]  1072.953773: block_getrq: 0,0 N 0 + 0 [bash]

rq_complete:
  konsole-2065  [001]   300.053184: block_rq_complete: 8,0 W () 103669040 + 16 [0]
  konsole-2065  [001]   300.053191:   8,0    C   W 103669040 + 16 [0]

  ksoftirqd/1-7   [001]  1072.953811:   8,0    C   N (5a 00 08 00 00 00 00 00 24 00) [0]
  ksoftirqd/1-7   [001]  1072.953813: block_rq_complete: 0,0 N (5a 00 08 00 00 00 00 00 24 00) 0 + 0 [0]

rq_insert:
  kjournald-480   [000]   303.084985: block_rq_insert: 8,0 W 0 () 102736984 + 8 [kjournald]
  kjournald-480   [000]   303.084986:   8,0    I   W 102736984 + 8 [kjournald]

Changelog from v2 -> v3:

- use the newly introduced __dynamic_array().

Changelog from v1 -> v2:

- use __string() instead of __array() to minimize the memory required
  to store hex dump of rq->cmd().

- support large pc requests.

- add missing blk_fill_rwbs_rq() in block_rq_requeue TRACE_EVENT.

- some cleanups.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A2DF669.5070905@cn.fujitsu.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Some JIT compilers allocate memory for generated code with
posix_memalign() + mprotect() so we need to hook into mprotect()
to make sure 'perf' is aware that we're executing code in
anonymous memory.

[ penberg@cs.helsinki.fi: move the hook to sys_mprotect() ]
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <Pine.LNX.4.64.0906082111030.12407@melkki.cs.Helsinki.FI>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In order to track the vdso also generate mmap events for
install_special_mapping().
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In name of keeping it simple, only track mmap events. Userspace
will have to remove old overlapping maps when it encounters them.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch removes the dependency of mmap_min_addr on CONFIG_SECURITY.
It also sets a default mmap_min_addr of 4096.

mmapping of addresses below 4096 will only be possible for processes
with CAP_SYS_RAWIO.
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Acked-by: NEric Paris <eparis@redhat.com>
Looks-ok-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix build warning, "mem_cgroup_is_obsolete defined but not used" when
CONFIG_DEBUG_VM is not set.  Also avoid checking for !mem again and again.
Signed-off-by: NNikanth Karthikesan <knikanth@suse.de>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13302

hugetlbfs reserves huge pages but does not fault them at mmap() time to
ensure that future faults succeed.  The reservation behaviour differs
depending on whether the mapping was mapped MAP_SHARED or MAP_PRIVATE.
For MAP_SHARED mappings, hugepages are reserved when mmap() is first
called and are tracked based on information associated with the inode.
Other processes mapping MAP_SHARED use the same reservation.  MAP_PRIVATE
track the reservations based on the VMA created as part of the mmap()
operation.  Each process mapping MAP_PRIVATE must make its own
reservation.

hugetlbfs currently checks if a VMA is MAP_SHARED with the VM_SHARED flag
and not VM_MAYSHARE.  For file-backed mappings, such as hugetlbfs,
VM_SHARED is set only if the mapping is MAP_SHARED and the file was opened
read-write.  If a shared memory mapping was mapped shared-read-write for
populating of data and mapped shared-read-only by other processes, then
hugetlbfs would account for the mapping as if it was MAP_PRIVATE.  This
causes processes to fail to map the file MAP_SHARED even though it should
succeed as the reservation is there.

This patch alters mm/hugetlb.c and replaces VM_SHARED with VM_MAYSHARE
when the intent of the code was to check whether the VMA was mapped
MAP_SHARED or MAP_PRIVATE.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <starlight@binnacle.cx>
Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mapping->tree_lock can be acquired from interrupt context.  Then,
following dead lock can occur.

Assume "A" as a page.

 CPU0:
       lock_page_cgroup(A)
		interrupted
			-> take mapping->tree_lock.
 CPU1:
       take mapping->tree_lock
		-> lock_page_cgroup(A)

This patch tries to fix above deadlock by moving memcg's hook to out of
mapping->tree_lock.  charge/uncharge of pagecache/swapcache is protected
by page lock, not tree_lock.

After this patch, lock_page_cgroup() is not called under mapping->tree_lock.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When /proc/sys/vm/oom_dump_tasks is enabled, it is possible to get a NULL
pointer for tasks that have detached mm's since task_lock() is not held
during the tasklist scan.  Add the task_lock().
Acked-by: NNick Piggin <npiggin@suse.de>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert all external users of queue limits to using wrapper functions
instead of poking the request queue variables directly.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Based on discussion on lkml (Andrew Morton and Eric Paris),
move ima_counts_get down a layer into shmem/hugetlb__file_setup().
Resolves drm shmem_file_setup() usage case as well.

HD comment:
  I still think you're doing this at the wrong level, but recognize
  that you probably won't be persuaded until a few more users of
  alloc_file() emerge, all wanting your ima_counts_get().

  Resolving GEM's shmem_file_setup() is an improvement, so I'll say
Acked-by: NHugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

- Add support in ima_path_check() for integrity checking without
incrementing the counts. (Required for nfsd.)
- rename and export opencount_get to ima_counts_get
- replace ima_shm_check calls with ima_counts_get
- export ima_path_check
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

My old address will shut down in a few days time: remove it from the tree,
and add a tmpfs (shmem filesystem) maintainer entry with the new address.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NHugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pfn_valid() is meant to be able to tell if a given PFN has valid memmap
associated with it or not. In FLATMEM, it is expected that holes always
have valid memmap as long as there is valid PFNs either side of the hole.
In SPARSEMEM, it is assumed that a valid section has a memmap for the
entire section.

However, ARM and maybe other embedded architectures in the future free
memmap backing holes to save memory on the assumption the memmap is never
used. The page_zone linkages are then broken even though pfn_valid()
returns true. A walker of the full memmap must then do this additional
check to ensure the memmap they are looking at is sane by making sure the
zone and PFN linkages are still valid. This is expensive, but walkers of
the full memmap are extremely rare.

This was caught before for FLATMEM and hacked around but it hits again for
SPARSEMEM because the page_zone linkages can look ok where the PFN linkages
are totally screwed. This looks like a hatchet job but the reality is that
any clean solution would end up consumning all the memory saved by punching
these unexpected holes in the memmap. For example, we tried marking the
memmap within the section invalid but the section size exceeds the size of
the hole in most cases so pfn_valid() starts returning false where valid
memmap exists. Shrinking the size of the section would increase memory
consumption offsetting the gains.

This patch identifies when an architecture is punching unexpected holes
in the memmap that the memory model cannot automatically detect and sets
ARCH_HAS_HOLES_MEMORYMODEL. At the moment, this is restricted to EP93xx
which is the model sub-architecture this has been reported on but may expand
later. When set, walkers of the full memmap must call memmap_valid_within()
for each PFN and passing in what it expects the page and zone to be for
that PFN. If it finds the linkages to be broken, it assumes the memmap is
invalid for that PFN.
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

after:

 | commit b263295d
 | Author: Christoph Lameter <clameter@sgi.com>
 | Date:   Wed Jan 30 13:30:47 2008 +0100
 |
 |    x86: 64-bit, make sparsemem vmemmap the only memory model

we don't have MEMORY_HOTPLUG_RESERVE anymore.

Historically, x86-64 had an architecture-specific method for memory hotplug
whereby it scanned the SRAT for physical memory ranges that could be
potentially used for memory hot-add later. By reserving those ranges
without physical memory, the memmap would be allocated and left dormant
until needed. This depended on the DISCONTIG memory model which has been
removed so the code implementing HOTPLUG_RESERVE is now dead.

This patch removes the dead code used by MEMORY_HOTPLUG_RESERVE.

(Changelog authored by Mel.)

v2: updated changelog, and remove hotadd= in doc

[ Impact: remove dead code ]
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Reviewed-by: NChristoph Lameter <cl@linux-foundation.org>
Reviewed-by: NMel Gorman <mel@csn.ul.ie>
Workflow-found-OK-by: NAndrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A0C4910.7090508@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

wb_kupdate() function has a bug on linux-2.6.30-rc5.  This bug causes
generic_sync_sb_inodes() to start to write inodes back much earlier than
our expectations because it miscalculates oldest_jif in wb_kupdate().

This bug was introduced in 704503d8
('mm: fix proc_dointvec_userhz_jiffies "breakage"').
Signed-off-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
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>

This reverts commit fafd688e.

Work is progressing to switch away from pdflush as the process backing
for flushing out dirty data. So it seems pointless to add more knobs
to control pdflush threads. The original author of the patch did not
have any specific use cases for adding the knobs, so we can easily
revert this before 2.6.30 to avoid having to maintain this API
forever.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

This reverts commit a425a638.

Now that the previous commit removed the "readpage" actor for hugetlb
files, read-ahead will no longer mess up the mapping, and there's no
longer any reason to treat hugetlbfs mappings specially.
Tested-and-acked-by: NMel Gorman <mel@csn.ul.ie>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't check vm_region::vm_start is page aligned in add_nommu_region() because
the region may reflect some non-page-aligned mapped file, such as could be
obtained from RomFS XIP.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NGreg Ungerer <gerg@uclinux.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

NOMMU mmap() has an option controlled by a sysctl variable that determines
whether the allocations made by do_mmap_private() should have the excess
space trimmed off and returned to the allocator.  Make the initial setting
of this variable a Kconfig configuration option.

The reason there can be excess space is that the allocator only allocates
in power-of-2 size chunks, but mmap()'s can be made in sizes that aren't a
power of 2.

There are two alternatives:

 (1) Keep the excess as dead space.  The dead space then remains unused for the
     lifetime of the mapping.  Mappings of shared objects such as libc, ld.so
     or busybox's text segment may retain their dead space forever.

 (2) Return the excess to the allocator.  This means that the dead space is
     limited to less than a page per mapping, but it means that for a transient
     process, there's more chance of fragmentation as the excess space may be
     reused fairly quickly.

During the boot process, a lot of transient processes are created, and
this can cause a lot of fragmentation as the pagecache and various slabs
grow greatly during this time.

By turning off the trimming of excess space during boot and disabling
batching of frees, Coldfire can manage to boot.

A better way of doing things might be to have /sbin/init turn this option
off.  By that point libc, ld.so and init - which are all long-duration
processes - have all been loaded and trimmed.
Reported-by: NLanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NLanttor Guo <lanttor.guo@freescale.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clamp zone_batchsize() to 0 under NOMMU conditions to stop
free_hot_cold_page() from queueing and batching frees.

The problem is that under NOMMU conditions it is really important to be
able to allocate large contiguous chunks of memory, but when munmap() or
exit_mmap() releases big stretches of memory, return of these to the buddy
allocator can be deferred, and when it does finally happen, it can be in
small chunks.

Whilst the fragmentation this incurs isn't so much of a problem under MMU
conditions as userspace VM is glued together from individual pages with
the aid of the MMU, it is a real problem if there isn't an MMU.

By clamping the page freeing queue size to 0, pages are returned to the
allocator immediately, and the buddy detector is more likely to be able to
glue them together into large chunks immediately, and fragmentation is
less likely to occur.

By disabling batching of frees, and by turning off the trimming of excess
space during boot, Coldfire can manage to boot.
Reported-by: NLanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NLanttor Guo <lanttor.guo@freescale.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use roundown_pow_of_two(N) in zone_batchsize() rather than (1 <<
(fls(N)-1)) as they are equivalent, and with the former it is easier to
see what is going on.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NLanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>