sched: Folding nohz load accounting more accurate

After patch 453494c3d4 (sched: Fix nohz load accounting -- again!), we can fold
the idle into calc_load_tasks_idle between the last cpu load calculating and
calc_global_load calling. However problem still exits between the first cpu
load calculating and the last cpu load calculating. Every time when we do load
calculating, calc_load_tasks_idle will be added into calc_load_tasks, even if
the idle load is caused by calculated cpus. This problem is also described in
the following link:

https://lkml.org/lkml/2012/5/24/419

This bug can be found in our work load. The average running processes number
is about 15, but the load only shows about 4.

The patch provides a solution, by taking calculated load cpus' idle away from
 real effective idle. First adds a cpumask to record those cpus that alread
calculated their load, and then adds a calc_unmask_cpu_load_idle to record
thoses not marked cpus' go-idle load. Calc_unmask_cpu_load_idle takes place
of calc_load_tasks_idle to be added into calc_load_tasks every 5HZ when cpu
calculate its load. Go-idle load on those cpus which load alread has been calculated
will only be added into calc_load_tasks_idle, no in calc_unmask_cpu_load_idle.

Reported-by: Sha Zhengju <handai.szj@xxxxxxxxx>
Signed-off-by: Charles Wang <muming.wq@xxxxxxxxxx>
modified for HTC One X kernel from Linux 3.4+ by faux123
block/deadline: tweaked for better performance on android
arm/crypto: Add optimized AES and SHA1 routines

Add assembler versions of AES and SHA1 for ARM platforms.  This has provided
up to a 50% improvement in IPsec/TCP throughout for tunnels using AES128/SHA1.

Platform   CPU SPeed    Endian   Before (bps)   After (bps)   Improvement

IXP425      533 MHz      big     11217042        15566294        ~38%
KS8695      166 MHz     little    3828549         5795373        ~51%

Signed-off-by: David McCullough <ucdevel@gmail.com>
lib/lzo: Rename lzo1x_decompress.c to lzo1x_decompress_safe.c

Rename the source file to match the function name and thereby
also make room for a possible future even slightly faster
"non-safe" decompressor version.

Signed-off-by: Markus F.X.J. Oberhumer <markus@oberhumer.com>
lib/lzo: Update LZO compression to current upstream version

This commit updates the kernel LZO code to the current upsteam version
which features a significant speed improvement - benchmarking the Calgary
and Silesia test corpora typically shows a doubled performance in
both compression and decompression on modern i386/x86_64/powerpc machines.

Signed-off-by: Markus F.X.J. Oberhumer <markus@oberhumer.com>
Proportional Rate Reduction for TCP.

This patch implements Proportional Rate Reduction (PRR) for TCP.
PRR is an algorithm that determines TCP's sending rate in fast
recovery. PRR avoids excessive window reductions and aims for
the actual congestion window size at the end of recovery to be as
close as possible to the window determined by the congestion control
algorithm. PRR also improves accuracy of the amount of data sent
during loss recovery.

The patch implements the recommended flavor of PRR called PRR-SSRB
(Proportional rate reduction with slow start reduction bound) and
replaces the existing rate halving algorithm. PRR improves upon the
existing Linux fast recovery under a number of conditions including:
  1) burst losses where the losses implicitly reduce the amount of
outstanding data (pipe) below the ssthresh value selected by the
congestion control algorithm and,
  2) losses near the end of short flows where application runs out of
data to send.

As an example, with the existing rate halving implementation a single
loss event can cause a connection carrying short Web transactions to
go into the slow start mode after the recovery. This is because during
recovery Linux pulls the congestion window down to packets_in_flight+1
on every ACK. A short Web response often runs out of new data to send
and its pipe reduces to zero by the end of recovery when all its packets
are drained from the network. Subsequent HTTP responses using the same
connection will have to slow start to raise cwnd to ssthresh. PRR on
the other hand aims for the cwnd to be as close as possible to ssthresh
by the end of recovery.

A description of PRR and a discussion of its performance can be found at
the following links:
- IETF Draft:
    http://tools.ietf.org/html/draft-mathis-tcpm-proportional-rate-reduction-01
- IETF Slides:
    http://www.ietf.org/proceedings/80/slides/tcpm-6.pdf
    http://tools.ietf.org/agenda/81/slides/tcpm-2.pdf
- Paper to appear in Internet Measurements Conference (IMC) 2011:
    Improving TCP Loss Recovery
    Nandita Dukkipati, Matt Mathis, Yuchung Cheng

Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
defconfig: use arm optimized crypto algos
lowmemorykiller: Compact memory when killing processes

* Memory compaction is never invoked on Android because we avoid swap
   and don't allocate huge pages. Fix it by invoking compaction from the LMK when
   a process is killed to reduce memory fragmentation.

Change-Id: I2bda790c2093e65fd6f43d52ea5149d6b57cb1e9

Conflicts:

	drivers/staging/android/lowmemorykiller.c
lowmemorykiller: Use asynchronous compaction

Change-Id: I6a65d06fc30b88fcedaaf1abf1855fdd19e3c912
drivers: staging: android: lmk compile fixup

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
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.

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>
drivers: cpufreq: make unlock_policy_rwsem_write/read non static

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
SCHEDULER: Autogroup patch group by current user android UID instead of task ID
ARM: smp: Fix cpu_up() racing with sys_reboot

Nothing stops a process from hotplugging in a CPU concurrently
with a sys_reboot() call. In such a situation we could have
ipi_cpu_stop() mark a cpu as 'offline' and _cpu_up() ignore the
fact that the CPU is not really offline and call the
CPU_UP_PREPARE notifier. When this happens stop_machine code will
complain that the cpu thread already exists and BUG_ON().

CPU0                      CPU1

sys_reboot()
 kernel_restart()
  machine_restart()
   machine_shutdown()
    smp_send_stop()
    ...                   ipi_cpu_stop()
                           set_cpu_online(1, false)
                            local_irq_disable()
                             while(1)
    <PREEMPT>
cpu_up()
 _cpu_up()
   if (!cpu_online(1))
    __cpu_notify(CPU_UP_PREPARE...)
cpu_stop_cpu_callback()
  BUG_ON(stopper->thread)

This is easily reproducible by hotplugging in and out in a tight
loop while also rebooting.

Since the CPU is not really offline and hasn't gone through the
proper steps to be marked as such, let's mark the CPU as inactive.
This is just as easily testable as online and avoids any possibility
of _cpu_up() trying to bring the CPU back online when it never was
offline to begin with.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
modified for tuna kernel by faux123 from Linux 3.5+
kernel/resource.c: fix stack overflow in __reserve_region_with_split

Using recurvise call to try adding a non-conflicting region in the function
__reserve_region_with_split() could result in a stack overflow in the case
that the recursive calls are too deep.  Convert the recursive calls to
an iterative loop to avoid the problem.

Signed-off-by: T Makphaibulchoke <tmac@hp.com>
staging: android/lowmemorykiller: Don't grab tasklist_lock

Grabbing tasklist_lock has its disadvantages, i.e. it blocks
process creation and destruction. If there are lots of processes,
blocking doesn't sound as a great idea.

For LMK, it is sufficient to surround tasks list traverse with
rcu_read_{,un}lock().

>From now on using force_sig() is not safe, as it can race with an
already exiting task, so we use send_sig() now. As a downside, it
won't kill PID namespace init processes, but that's not what we
want anyway.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
modified for HTC kernel from Linux 3.4+ by faux123

Conflicts:

	drivers/staging/android/lowmemorykiller.c
staging: android/lowmemorykiller: Better mm handling

LMK should not directly check for task->mm. The reason is that the
process' threads may exit or detach its mm via use_mm(), but other
threads may still have a valid mm. To catch this we use
find_lock_task_mm(), which walks up all threads and returns an
appropriate task (with lock held).

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
modified for HTC kernel from Linux 3.4+ by faux123
staging: android/lowmemorykiller: No need for task->signal check

task->signal == NULL is not possible, so no need for these checks.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
modified for HTC kernel from Linux 3.4+ by faux123
staging: android/lowmemorykiller: Do not kill kernel threads

LMK should not try killing kernel threads.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Staging: android: lowmemorykiller.c

Fix compiler warning about the type of the module parameter.

Cc: San Mehat <san@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>