staging: android: Add some Kconfig help entries

This commit adds Kconfig entries for the following:

	1: ANDROID_BINDER_IPC
	2: ASHMEM (additional text)
	3: ANDROID_LOGGER

It also changes "Register" to "Registers" in
ANDROID_LOW_MEMORY_KILLER

Finally, all "help" instances are changed to "---help---",
as recommended by kconfig-language.txt in order to visually
aid developers.

Signed-off-by: Cruz Julian Bishop <cruzjbishop@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seongmin Park <r_data@naver.com>
slub, hotplug: ignore unrelated node's hot-adding and hot-removing

SLUB only focuses on the nodes which have normal memory and it ignores the
other node's hot-adding and hot-removing.

Aka: if some memory of a node which has no onlined memory is online, but
this new memory onlined is not normal memory (for example, highmem), we
should not allocate kmem_cache_node for SLUB.

And if the last normal memory is offlined, but the node still has memory,
we should remove kmem_cache_node for that node.  (The current code delays
it when all of the memory is offlined)

So we only do something when marg->status_change_nid_normal > 0.
marg->status_change_nid is not suitable here.

The same problem doesn't exist in SLAB, because SLAB allocates kmem_list3
for every node even the node don't have normal memory, SLAB tolerates
kmem_list3 on alien nodes.  SLUB only focuses on the nodes which have
normal memory, it don't tolerate alien kmem_cache_node.  The patch makes
SLUB become self-compatible and avoids WARNs and BUGs in rare conditions.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Rob Landley <rob@landley.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
slub: remove one code path and reduce lock contention in __slab_free()

When we try to free object, there is some of case that we need
to take a node lock. This is the necessary step for preventing a race.
After taking a lock, then we try to cmpxchg_double_slab().
But, there is a possible scenario that cmpxchg_double_slab() is failed
with taking a lock. Following example explains it.

CPU A               CPU B
need lock
...                 need lock
...                 lock!!
lock..but spin      free success
spin...             unlock
lock!!
free fail

In this case, retry with taking a lock is occured in CPU A.
I think that in this case for CPU A,
"release a lock first, and re-take a lock if necessary" is preferable way.

There are two reasons for this.

First, this makes __slab_free()'s logic somehow simple.
With this patch, 'was_frozen = 1' is "always" handled without taking a lock.
So we can remove one code path.

Second, it may reduce lock contention.
When we do retrying, status of slab is already changed,
so we don't need a lock anymore in almost every case.
"release a lock first, and re-take a lock if necessary" policy is
helpful to this.

Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
arm: vfpmodule: Fix warning procfs vfp_bounce reporting failed

Creation of procfs cpu/vfp_bounce fails because we're initialized too early. Fix
this by creating it on rootfs_initcall as before the NEON patches.

<6>[    0.130770] VFP support v0.3: implementor 51 architecture 64 part 6f varia
nt 2 rev 0
<4>[    0.130795] ------------[ cut here ]------------
<4>[    0.130813] WARNING: at fs/proc/generic.c:323 __xlate_proc_name+0xac/0xcc(
)
<4>[    0.130822] name 'cpu/vfp_bounce'
<4>[    0.130855] [<c010e26c>] (unwind_backtrace+0x0/0x144) from [<c0a20f58>] (d
ump_stack+0x20/0x24)
<4>[    0.130879] [<c0a20f58>] (dump_stack+0x20/0x24) from [<c019b670>] (warn_sl
owpath_common+0x58/0x70)
<4>[    0.130899] [<c019b670>] (warn_slowpath_common+0x58/0x70) from [<c019b704>
] (warn_slowpath_fmt+0x40/0x48)
<4>[    0.130919] [<c019b704>] (warn_slowpath_fmt+0x40/0x48) from [<c02c2ad8>] (
__xlate_proc_name+0xac/0xcc)
<4>[    0.130938] [<c02c2ad8>] (__xlate_proc_name+0xac/0xcc) from [<c02c2b50>] (
__proc_create+0x58/0x100)
<4>[    0.130956] [<c02c2b50>] (__proc_create+0x58/0x100) from [<c02c2ed0>] (pro
c_create_data+0x5c/0xc0)
<4>[    0.130979] [<c02c2ed0>] (proc_create_data+0x5c/0xc0) from [<c0f03484>] (v
fp_init+0x19c/0x200)
<4>[    0.131000] [<c0f03484>] (vfp_init+0x19c/0x200) from [<c0f00c98>] (do_one_
initcall+0x98/0x168)
<4>[    0.131020] [<c0f00c98>] (do_one_initcall+0x98/0x168) from [<c0f00e60>] (k
ernel_init+0xf8/0x1b4)
<4>[    0.131043] [<c0f00e60>] (kernel_init+0xf8/0x1b4) from [<c01081a0>] (kerne
l_thread_exit+0x0/0x8)
<4>[    0.131076] ---[ end trace ea6d9a9b5e947151 ]---
<3>[    0.131086] Failed to create procfs node for VFP bounce reporting

Signed-off-by: Paul Reioux <reioux@gmail.com>