Added rek/logs placeholder
Especially on platforms with a slower CPU but a relatively high framebuffer fill bandwidth, like current ARM devices, the existing console monochrome imageblit function used to draw console text is suboptimal for common pixel depths such as 16bpp and 32bpp. The existing code is quite general and can deal with several pixel depths. By creating special case functions for 16bpp and 32bpp, by far the most common pixel formats used on modern systems, a significant speed-up is attained which can be readily felt on ARM-based devices like the Raspberry Pi and the Allwinner platform, but should help any platform using the fb layer.

The special case functions allow constant folding, eliminating a number
of instructions including divide operations, and allow the use of an
unrolled loop, eliminating instructions with a variable shift size,
reducing source memory access instructions, and eliminating excessive
branching. These unrolled loops also allow much better code optimization
by the C compiler. The code that selects which optimized variant is used
is also simplified, eliminating integer divide instructions.

The speed-up, measured by timing 'cat file.txt' in the console, varies
between 40% and 70%, when testing on the Raspberry Pi and Allwinner
ARM-based platforms, depending on font size and the pixel depth, with
the greater benefit for 32bpp.

Signed-off-by: Ka <k@ka.st>
deadline: Allow 0ms deadline latency, increase the read speed

Change a timer compare from after to after-equals, thus allowing
0 timeout and making deadline schedule FIFO.

Signed-off-by: xiaobing tu <xiaobing.tu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Ka <k@ka.st>
mm, vmalloc: remove useless variable in vmap_block

vbq in vmap_block isn't used. So remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Ka <k@ka.st>
mm, vmalloc: use well-defined find_last_bit() func

Our intention in here is to find last_bit within the region to flush.
There is well-defined function, find_last_bit() for this purpose and its
performance may be slightly better than current implementation.  So change
it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Ka <k@ka.st>
readahead: make context readahead more conservative

This helps performance on moderately dense random reads on SSD.

Transaction-Per-Second numbers provided by Taobao:

		QPS	case
		-------------------------------------------------------
		7536	disable context readahead totally
w/ patch:	7129	slower size rampup and start RA on the 3rd read
		6717	slower size rampup
w/o patch:	5581	unmodified context readahead

Before, readahead will be started whenever reading page N+1 when it happen
to read N recently.  After patch, we'll only start readahead when *three*
random reads happen to access pages N, N+1, N+2.  The probability of this
happening is extremely low for pure random reads, unless they are very
dense, which actually deserves some readahead.

Also start with a smaller readahead window.  The impact to interleaved
sequential reads should be small, because for a long run stream, the the
small readahead window rampup phase is negletable.

The context readahead actually benefits clustered random reads on HDD
whose seek cost is pretty high.  However as SSD is increasingly used for
random read workloads it's better for the context readahead to concentrate
on interleaved sequential reads.

Another SSD rand read test from Miao

        # file size:        2GB
        # read IO amount: 625MB
        sysbench --test=fileio          \
                --max-requests=10000    \
                --num-threads=1         \
                --file-num=1            \
                --file-block-size=64K   \
                --file-test-mode=rndrd  \
                --file-fsync-freq=0     \
                --file-fsync-end=off    run

shows the performance of btrfs grows up from 69MB/s to 121MB/s, ext4 from
104MB/s to 121MB/s.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Tested-by: Tao Ma <tm@tao.ma>
Tested-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Ka <k@ka.st>
mmc: disable crc for better performance

Signed-off-by: Ka <k@ka.st>
wireless: Fix memory leak

Signed-off-by: Ka <k@ka.st>
arm: show present cpu instead of online cpu in /proc/cpuinfo

Some userspace applications use /proc/cpuinfo to determine how many CPUs
the system has. CPU hotplug can offline a CPU at runtime and causing the
offline CPU not present in /proc/cpuinfo if we only show online cpu in
/proc/cpuinfo.

CRs-Fixed: 354430
Signed-off-by: Jin Hong <jinh@codeaurora.org>
(cherry picked from commit 1e28794d0ff00fc6567d68b5b4e863b0745cfe20)

Change-Id: I3b38472b690bb3dba67ada74f60cce79ed0b2a7d
Signed-off-by: Ram Kumar Chakravarthy Chebathini <rcheba@codeaurora.org>
Signed-off-by: Ka <k@ka.st>
cpufreq: conservative: update frequency when limits are relaxed

Reevaluate CPU load and update frequency immediately whenever limits
are changed. Currently conservative doesn't do that when limits are
relaxed, wasting power on systems with relatively low sampling rate.

Signed-off-by: Michal Pecio <mpecio@nvidia.com>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Ka <k@ka.st>
PM / cpufreq: Initialise the cpu field during conservative governor start

This change initialises the cpu id field of cs_cpu_dbs_info structure in
conservative governor and keep this consistent with other governors.
Similar initialisation is present in ondemand governor.

Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Ka <k@ka.st>
cpufreq: Memory leak with sysfs when stats table are freed

Signed-off-by: Ka <k@ka.st>
cpufreq: stats: Don't stop notification call chain

The notification call chain is stopped if error returned. Since
no further steps is needed to handle such error, let's just print
a debug message here so the other registered cpufreq notifier can
be called correctly.

Signed-off-by: Lianwei Wang <a22439@motorola.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Ka <k@ka.st>
Deadline tuning thanks to DerTeufel

Change-Id: Ieed33a2ab7f0481d1657df723b68640627e88095

Signed-off-by: Ka <k@ka.st>
mmc/core: increase limit_us

Signed-off-by: Ka <k@ka.st>
optimized rwsem

Signed-off-by: Ka <k@ka.st>
random: entropy tweaks are all the rage nowadays

use nonblocking for all.  Read this web page:
http://lwn.net/Articles/489734/

Signed-off-by: Ka <k@ka.st>
dm: use vzalloc

Use vzalloc() instead of vmalloc()+memset().

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
(cherry picked from commit e29e65aacbd9e628378084905cbcf62a9fa4a8cc)

Change-Id: I4701888bb6b595e403db1f99f44989d188363c29
Signed-off-by: Ka <k@ka.st>
ARM: 6998/2: kernel: use proper memory barriers for bitops

Improve scalability by avoiding costly and unnecessary L2 cache sync
in handling bitops.

Signed-off-by: Heechul Yun <hyun@nvidia.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ka <k@ka.st>
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: Ka <k@ka.st>