Add SLQB memory allocator by Nick Piggin

Change-Id: I8060a6a2a32c73b70d1921921e268ee9ff112812
init/main.c: execute lockdep_init as early as possible

From: Ming Lei <tom.leiming@gmail.com>

This patch removes the lockdep warning[1] on ARM platform.
The warning is caused by printk inside smp_setup_processor_id.

It is safe to do this because lockdep_init doesn't depend on
smp_setup_processor_id, so make printk can be called as early
as possible without lockdep complainment.

[1], lockdep warning
[    0.000000] WARNING: lockdep init error! Arch code didn't call
lockdep_init() early enough?
[    0.000000] Call stack leading to lockdep invocation was:
[    0.000000]  [<c00164bc>] save_stack_trace_tsk+0x0/0x90
[    0.000000]  [<ffffffff>] 0xffffffff
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
ARM: Add optimised swahb32() byteswap helper for v6 and above

ARMv6 and later processors have the REV16 instruction, which swaps
the bytes within each halfword of a register value.

This is already used to implement swab16(), but since the native
operation performaed by REV16 is actually swahb32(), this patch
renames the existing swab16() helper accordingly and defines
__arch_swab16() in terms of it.  This allows calls to both swab16()
and swahb32() to be optimised.

The compiler's generated code might improve someday, but as of
4.5.2 the code generated for pure C implementing these 16-bit
bytesswaps remains pessimal.

swahb32() is useful for converting 32-bit Thumb instructions
between integer and memory representation on BE8 platforms (among
other uses).

Signed-off-by: Dave Martin <dave.martin@xxxxxxxxxx>
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>
lib/sha1: use the git implementation of SHA-1

For ChromiumOS, we use SHA-1 to verify the integrity of the root
filesystem.  The speed of the kernel sha-1 implementation has a major
impact on our boot performance.

To improve boot performance, we investigated using the heavily optimized
sha-1 implementation used in git.  With the git sha-1 implementation, we
see a 11.7% improvement in boot time.

10 reboots, remove slowest/fastest.

Before:

  Mean: 6.58 seconds Stdev: 0.14

After (with git sha-1, this patch):

  Mean: 5.89 seconds Stdev: 0.07

The other cool thing about the git SHA-1 implementation is that it only
needs 64 bytes of stack for the workspace while the original kernel
implementation needed 320 bytes.

Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Cc: Nicolas Pitre <nico@cam.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RCU: Joe's RCU

Forward port jRCU to linux-3.0.

Thanks goes to Francisco Franco for his help
in testing out this version on the Android
Galaxy Nexus phone.

Signed-off-by: Joe Korty <joe.korty@ccur.com>
ARM: vmlinux.lds.S: do not hardcode cacheline size as 32 bytes

The linker script assumes a cacheline size of 32 bytes when aligning
the .data..cacheline_aligned and .data..percpu sections.

This patch updates the script to use L1_CACHE_BYTES, which should be set
to 64 on platforms that require it.

Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
ARM: vmlinux.lds.S: align the exception fixup table to a 4-byte boundary

The exception fixup table is currently aligned to a 32-byte boundary.
Whilst this won't cause any problems, the exception_table_entry
structures contain only a pair of unsigned longs, so 4-byte alignment
is all that is required.

Cc: Nicolas Pitre <nico@xxxxxxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
ARM: cache: assume 64-byte L1 cachelines for ARMv7 CPUs

To ensure correct alignment of cacheline-aligned data, the maximum
cacheline size needs to be known at compile time.

Since Cortex-A8 and Cortex-A15 have 64-byte cachelines (and it is likely
that there will be future ARMv7 implementations with the same line size)
then it makes sense to assume that CPU_V7 implies a 64-byte L1 cacheline
size. For CPUs with smaller caches, this will result in some harmless
padding but will help with single zImage work and avoid hitting subtle
bugs with misaligned data structures.

Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Optimized ARM RWSEM algorithm

RWSEM implementation for ARM using atomic functions.
Heavily based on arch/sh/include/asm/rwsem.h

Signed-off-by: Ashwin Chaugule <ashwinc@codeaurora.org>
procfs: add num_to_str() to speed up /proc/stat

== stat_check.py
num = 0
with open("/proc/stat") as f:
        while num < 1000 :
                data = f.read()
                f.seek(0, 0)
                num = num + 1
==

perf shows

    20.39%  stat_check.py  [kernel.kallsyms]    [k] format_decode
    13.41%  stat_check.py  [kernel.kallsyms]    [k] number
    12.61%  stat_check.py  [kernel.kallsyms]    [k] vsnprintf
    10.85%  stat_check.py  [kernel.kallsyms]    [k] memcpy
     4.85%  stat_check.py  [kernel.kallsyms]    [k] radix_tree_lookup
     4.43%  stat_check.py  [kernel.kallsyms]    [k] seq_printf

This patch removes most of calls to vsnprintf() by adding num_to_str()
and seq_print_decimal_ull(), which prints decimal numbers without rich
functions provided by printf().

On my 8cpu box.
== Before patch ==
[root@bluextal test]# time ./stat_check.py

real    0m0.150s
user    0m0.026s
sys     0m0.121s

== After patch ==
[root@bluextal test]# time ./stat_check.py

real    0m0.055s
user    0m0.022s
sys     0m0.030s

[akpm@linux-foundation.org: remove incorrect comment, use less statck in num_to_str(), move comment from .h to .c, simplify seq_put_decimal_ull()]
[andrea@betterlinux.com: avoid breaking the ABI in /proc/stat]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Righi <andrea@betterlinux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Turner <pjt@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
backported from Linux 3.4-rc4 to Linux 3.0.x by faux123
vsprintf: optimize decimal conversion (again)

    This patch is based upon an original from Michal Nazarewicz.

    Previous code was using optimizations which were developed
    to work well even on narrow-word CPUs (by today's standards).
    But Linux runs only on 32-bit and wider CPUs. We can use that.

    First: using 32x32->64 multiply and trivial 32-bit shift,
    we can correctly divide by 10 much larger numbers, and thus
    we can print groups of 9 digits instead of groups of 5 digits.

    Next: there are two algorithms to print larger numbers.
    One is generic: divide by 1000000000 and repeatedly print
    groups of (up to) 9 digits. It's conceptually simple,
    but requires an (unsigned long long) / 1000000000 division.
    Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
    manipulates them cleverly and generates groups of 4 decimal digits.
    It so happens that it does NOT require long long division.

    If long is > 32 bits, division of 64-bit values is relatively easy,
    and we will use the first algorithm.
    If long long is > 64 bits (strange architecture with VERY large long long),
    second algorithm can't be used, and we again use the first one.
    Else (if long is 32 bits and long long is 64 bits) we use second one.

    And third: there is a simple optimization which takes fast path
    not only for zero as was done before, but for all one-digit numbers.

    In all tested cases new code is faster than old one, in many cases by 30%,
    in few cases by more than 50% (for example, on x86-32, conversion of 12345678).
    Code growth is ~0 in 32-bit case and ~130 bytes in 64-bit case.

    Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
    Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
    Cc: Douglas W Jones <jones@cs.uiowa.edu>a
    backported from Linux 3.4+ to Linux 3.0 by faux123
ARM: rwlocks: remove unused branch labels from trylock routines

The ARM arch_{read,write}_trylock implementations include unused
backwards branch labels, since we don't retry the locking operation
if the exclusive store fails.

This patch removes the labels.

Signed-off-by: Will Deacon <will.deacon@arm.com>
ARM: spinlock: use ticket algorithm for ARMv6+ locking implementation

Ticket spinlocks ensure locking fairness by reducing the thundering herd
effect when acquiring a lock. This is especially important on systems
where memory-access times are not necessarily uniform when accessing
the lock structure (for example, on a multi-cluster platform where the
lock is allocated into L1 when a CPU releases it).

This patch implements the ticket spinlock algorithm for ARM, replacing
the simpler implementation for ARMv6+ processors.

Signed-off-by: Will Deacon <will.deacon@arm.com>
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%

Change-Id: I02962ee53ba1d40a3e61f1e46dec9166d0344bab
Signed-off-by: David McCullough <ucdevel@gmail.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>
fs/dyn_sync_cntrl: dynamic sync control

The dynamic sync control interface uses Android kernel's unique early
suspend / lat resume interface.

While screen is on, file sync is disabled
when screen is off, a file sync is called to flush all outstanding writes
and restore file sync operation as normal.
modified for Exynos Kernel

Change-Id: I17808ca6dfd021e4476f90580735e6fd8a8d2120
Signed-off-by: Paul Reioux <reioux@gmail.com>
scheduler: compute time-average nr_running per run-queue

Compute the time-average number of running tasks per run-queue for a
trailing window of a fixed time period. The detla add/sub to the
average value is weighted by the amount of time per nr_running value
relative to the total measurement period.

Change-Id: I076e24ff4ed65bed3b8dd8d2b279a503318071ff
Signed-off-by: Diwakar Tundlam <dtundlam@nvidia.com>
(cherry picked from commit 3a12d7499cee352e8a46eaf700259ba3c733f0e3)
Reviewed-on: http://git-master/r/111635
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Tested-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Reviewed-by: Peter Boonstoppel <pboonstoppel@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
proc: enhance time-average nr_running stats

Add time-average nr_running to loadavg printout

Bug 958978

Change-Id: I5c6904efb52a86f4964eb66c1576fc91f60f5b1d
Signed-off-by: Alex Frid <afrid@nvidia.com>
(cherry picked from commit 86f3642cc44a69d1e4798719bd9182cd6923f526)
Reviewed-on: http://git-master/r/111636
Reviewed-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Tested-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Peter Boonstoppel <pboonstoppel@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>