staging: android: lowmemorykiller: Management of not killable processes

This feature allows the user to define processes and system processes
white-lists filled with the preferred process names and to not be killed
by lowmemorykiller, unless it is absolutely necessary.

This feature exposes four new lowmemorykiller parameters:
- donotkill_proc, is the flag to enable / disable this feature for the
  processes chosen by the user
- donotkill_sysproc, is the flag to enable / disable this feature for the
  system processes chosen by the user
- donotkill_proc_names, is the list of process names (comma separated)
  chosen by the user to be preserved from killing
- donotkill_sysproc_names, is the list of user system process names (comma separated)
  chosen by the user to be preserved from killing

When a the lowmemorykiller needs to free ram, it will first kill the processes
not included inside the two process name lists chosen by the user.
If there are no more standard killable processes, then it will be necessary to
kill one of the processes included inside one of the two white-lists, to
prevent system hangs, slowdowns, etc.

Signed-off-by: Dan Trifan <jimsth@gmail.com>
defconfig: enable CONFIG_ANDROID_LOW_MEMORY_KILLER_DO_NOT_KILL_PROCESS

Signed-off-by: Dan Trifan <jimsth@gmail.com>
Linux v3.0.95

This is the 3.0.95 stable release.

Signed-off-by: Dan Trifan <jimsth@gmail.com>
defconfig: more autogenerated stuff

Signed-off-by: Dan Trifan <jimsth@gmail.com>
version 0.7.5_exp_bm

Signed-off-by: Dan Trifan <jimsth@gmail.com>
[PATCH 2/3] Optimize copy_page for modern ARM platforms

The existing implementation of copy_page for ARM appears to be
optimized for older platforms. Benchmark testing in a sandbox
environment shows suboptimal performance on modern platforms
like armv6 and armv7, with speed-ups ranging from 10% (Cortex A8)
to 80% (armv6 used in Raspberry Pi) being achievable.

This commit optimizes copy_page and introduces the new compile-time
constant PREFETCH_DISTANCE, defined in cache.h, which when
multiplied by L1_CACHE_BYTES is equal to the offset used for
prefetches performed with the PLD instruction. For platforms where
L1_CACHE_BYTES is 32 (armv5 and armv6), copy_page processes 32 bytes
at a time while doing one prefetch per iteration, while for armv7
(with L1_CACHE_BYTES equal to 64), 64 bytes are processed at at time
with one prefetch per iteration. When no preload instruction is
available (platforms earlier than armv5), no preload instructions
are generated and 32 bytes are processed at at time.

To facilitate specifying instructions for architectures with no
preload instruction, the NO_PLD macro is added to assembler.h,
augmenting the PLD macro.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Signed-off-by: Dan Trifan <jimsth@gmail.com>
ARM: 7301/1: Rename the T() macro to TUSER() to avoid namespace conflicts

This macro is used to generate unprivileged accesses (LDRT/STRT) to user
space.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Dan Trifan <jimsth@gmail.com>
[PATCH 1/3] Rename ARM assembler push/pull macros

The ARM assembler library functions use a macro called "push" that
along with a macro called "pull" is used to shift bytes around in a
word in an endian-independent way. However, the modern unified
ARM assembler syntax also defines the instruction "push" to push
data onto the stack, which has specific encodings in the Thumb2
instruction set. For prevent possible conflicts going forward, and
to allow the use of the more transparent "push" instruction along
with the modern unified assembler syntax, this patch renames all
occurrences of the "push" macro to "pushbits", as well as renaming
the macro argument, when also called "push", to "pushshift".

For consistency, the macro called "pull" with its argument name
"pull" are also renamed to "pullbits" and "pullshift", respectively.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Signed-off-by: Dan Trifan <jimsth@gmail.com>
[PATCH 3/3] Optimize ARM memset and memzero functions

The ARM memset and memzero functions are optimized with lower overhead
for small requests, generation of more 16-bit Thumb2 instructions when
compiled in Thumb2 mode, and configurable destination alignment before
the main block-copying loop.

The new compile-time constant MEMSET_WRITE_ALIGN_BYTES is introduced
in assembler.h, to augment the CALGN macro that previously regulated
32-byte write alignment but was only used on the Feroceon platform.
MEMSET_WRITE_ALIGN_BYTES can have values of 0 (no write alignment),
8, or 32. Apart from Feroceon, memset write alignment of 32 bytes
appears to benefit the armv6 platform, while the armv7 platform
seems benefit from alignment to 8 bytes for memset/memzero.

The CALGN macro is renamed to MEMSET_CALGN for memset and memzero; the
original CALGN macro is reserved for the memcpy family of functions
(memcpy, copy_from_user, copy_to_user) currently implemented in
copy_template.S, and the associated compile time constant
WRITE_ALIGN_BYTES defines the write alignment for memcpy-related
functions that will be utilized in subsequent contributions. Because
the current CALGN implementation in copy_template.S only implements
32-byte write alignment and is broken on Thumb2, it is only enabled
when WRITE_ALIGN_BYTES is equal to 32 and Thumb2 mode is not enabled.

Finally, memset and memzero now include a directive to enable unified
ARM assembler syntax.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Signed-off-by: Dan Trifan <jimsth@gmail.com>
ARM: assembler.h: use same WRITE_ALIGN_BYTES on omap4 as on armv6 platforms

Not all armv7 have 64 kbytes of l1 cache, for example the
Cortex-A9, which has 32 kbytes. As all omap4 platforms also
run Cortex-A9, adjust WRITE_ALIGN_BYTES accordingly.

Still needs testing.

Signed-off-by: Dan Trifan <jimsth@gmail.com>
defconfig: tuna default vmsplit

Signed-off-by: Dan Trifan <jimsth@gmail.com>
oom: fix race while temporarily setting current's oom_score_adj

test_set_oom_score_adj() was introduced in 72788c385604 ("oom: replace
PF_OOM_ORIGIN with toggling oom_score_adj") to temporarily elevate
current's oom_score_adj for ksm and swapoff without requiring an
additional per-process flag.

Using that function to both set oom_score_adj to OOM_SCORE_ADJ_MAX and
then reinstate the previous value is racy since it's possible that
userspace can set the value to something else itself before the old value
is reinstated.  That results in userspace setting current's oom_score_adj
to a different value and then the kernel immediately setting it back to
its previous value without notification.

To fix this, a new compare_swap_oom_score_adj() function is introduced
with the same semantics as the compare and swap CAS instruction, or
CMPXCHG on x86.  It is used to reinstate the previous value of
oom_score_adj if and only if the present value is the same as the old
value.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Trifan <jimsth@gmail.com>

Conflicts:

	mm/swapfile.c
modified by faux123

Signed-off-by: Dan Trifan <jimsth@gmail.com>
defconfig: enable ksm

Signed-off-by: Dan Trifan <jimsth@gmail.com>