staging: android: logger.h: Complete documentation of logger_entry

Previously, there were simply comments after each part - Now, it is
completed properly according to "Kernel doc" Sorry in advance if I made
any mistakes.

Signed-off-by: Cruz Julian Bishop <cruzjbishop@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: Improve logging

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: Allow to completely disable

* Logger is completely disabled on kernel_common branch.
* Let's disable it via userspace and give option to
  user to re-enable it when required.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: Allocate logs dynamically at boot (v3)

This changes the log initialization to be dynamic, but still
at boot time.  These changes are a predecessor to implementing
runtime allocation and freeing of logs, to make the Android logger
less hard-coded.

Change from a fixed set of static log structures, to allocation
at init time into a list.  Return proper error numbers on log
allocation failure.

Cc: Brian Swetland <swetland@google.com>
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: Android: Fix some checkpatch warnings

Warnings reported by checkpatch.pl have been fixed.

Cc: Brian Swetland <swetland@google.com>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: Finish documentation of two structs

Signed-off-by: Cruz Julian Bishop <cruzjbishop@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: Fix some sparse and whitespace issues

Fix a few sparse warnings, and improve whitespace.

Cc: Brian Swetland <swetland@google.com>
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: enforce GID and CAP check on log flush

Restrict log flushing to those in the logs group, or
anyone with CAP_SYSLOG.

Cc: Android Kernel Team <kernel-team@android.com>
Cc: Charndeep Grewal <csgrewa@tycho.ncsc.mil>
Signed-off-by: Charndeep Grewal <csgrewa@tycho.ncsc.mil>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Staging: Android: logger: module_exit implementation

This patch creates the module_exit for the android logger
so that it can be loaded and unloaded as a module.

The android logger is already declared as a tristate in the
Kconfig but the module_exit function was missing.

device_initcall works also with modprobe since include/linux/init.h:

 #define module_init(x)  __initcall(x);
 ...
 #define __initcall(fn) device_initcall(fn)

Signed-off-by: Luca Clementi <luca.clementi@gmail.com>
Cc: Brian Swetland <swetland@google.com>
Cc: Robert Love <rlove@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: Correct write offset reset on error

In the situation that a writer fails to copy data from userspace it will reset
the write offset to the value it had before it went to sleep. This discarding
any messages written while aquiring the mutex.

Therefore the reset offset needs to be retrieved after acquiring the mutex.

Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: logger: disable at boot
staging: android: logger: switch to powersuspend drivers
earlysuspend: speedup late resume (faster wakeup of the device)

Thanx to _2bad4u_ for the hint and dsc-team's repo I got the code from (https://github.com/dsc-team/dsc-team-kernel-project)
block: disable add_random for more performance on SSD's
mm: slub: Default slub_max_order to 0

To avoid locking and per-cpu overhead, SLUB optimisically uses
high-order allocations up to order-3 by default and falls back to
lower allocations if they fail. While care is taken that the caller
and kswapd take no unusual steps in response to this, there are
further consequences like shrinkers who have to free more objects to
release any memory. There is anecdotal evidence that significant time
is being spent looping in shrinkers with insufficient progress being
made (https://lkml.org/lkml/2011/4/28/361) and keeping kswapd awake.

SLUB is now the default allocator and some bug reports have been
pinned down to SLUB using high orders during operations like
copying large amounts of data. SLUBs use of high-orders benefits
applications that are sized to memory appropriately but this does not
necessarily apply to large file servers or desktops.  This patch
causes SLUB to use order-0 pages like SLAB does by default.
There is further evidence that this keeps kswapd's usage lower
(https://lkml.org/lkml/2011/5/10/383).

Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: flar2 <asegaert@gmail.com>
aio: fs: don't plug the I/O queue in do_io_submit()

Asynchronous I/O latency to a solid-state disk greatly increased between the 2.6.32 and 3.0 kernels.
By removing the plug from do_io_submit(), we observed a 34% improvement in the I/O latency.

Unfortunately, at this level, we don't know if the request is to
a rotating disk or not.

Change-Id: I7101df956473ed9fd5dcff18e473dd93b688a5c1
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: linux-aio@kvack.org
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Fix gcc-4.9.0 miscompilation of load_balance() in scheduler

commit 2062afb4f804afef61cbe62a30cac9a46e58e067 upstream.

Michel Dänzer and a couple of other people reported inexplicable random
oopses in the scheduler, and the cause turns out to be gcc mis-compiling
the load_balance() function when debugging is enabled.  The gcc bug
apparently goes back to gcc-4.5, but slight optimization changes means
that it now showed up as a problem in 4.9.0 and 4.9.1.

The instruction scheduling problem causes gcc to schedule a spill
operation to before the stack frame has been created, which in turn can
corrupt the spilled value if an interrupt comes in.  There may be other
effects of this bug too, but that's the code generation problem seen in
Michel's case.

This is fixed in current gcc HEAD, but the workaround as suggested by
Markus Trippelsdorf is pretty simple: use -fno-var-tracking-assignments
when compiling the kernel, which disables the gcc code that causes the
problem.  This can result in slightly worse debug information for
variable accesses, but that is infinitely preferable to actual code
generation problems.

Doing this unconditionally (not just for CONFIG_DEBUG_INFO) also allows
non-debug builds to verify that the debug build would be identical: we
can do

    export GCC_COMPARE_DEBUG=1

to make gcc internally verify that the result of the build is
independent of the "-g" flag (it will make the compiler build everything
twice, toggling the debug flag, and compare the results).

Without the "-fno-var-tracking-assignments" option, the build would fail
(even with 4.8.3 that didn't show the actual stack frame bug) with a gcc
compare failure.

See also gcc bugzilla:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801

Reported-by: Michel Dänzer <michel@daenzer.net>
Suggested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 7461/1: topology: Add arch_scale_freq_power function

Add infrastructure to be able to modify the cpu_power of each core

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ARM: 7462/1: topology: factorize the update of sibling masks

This factorization has also been proposed in another patch that has not been
merged yet:
http://lists.infradead.org/pipermail/linux-arm-kernel/2012-January/080873.html
So, this patch could be dropped depending of the state of the other one.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ARM: 7463/1: topology: Update cpu_power according to DT information

Use cpu compatibility field and clock-frequency field of DT to
estimate the capacity of each core of the system and to update
the cpu_power field accordingly.
This patch enables to put more running tasks on big cores than
on LITTLE ones. But this patch doesn't ensure that long running
tasks will run on big cores and short ones on LITTLE cores.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>