lib/checksum.c: optimize do_csum a bit

Reduce the number of variables modified by the loop in do_csum() by 1,
which seems like a good idea.  On Nios II (a RISC CPU with 3-operand
instruction set) it reduces the loop from 7 to 6 instructions, including
the conditional branch.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
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>
+ "Optimise apply_slack() for size and speed." - http://lkml.indiana.edu/hypermail/linux/kernel/1201.3/03172.html

To apply proper slack, the original algorithm used to prepare a mask and
then apply the mask to obtain the appropriately rounded-off absolute
time the timer expires.

This patch modifies the masking logic to a bit-shift logic, therby
reducing the complexity and number of operations. Thus obtaining a minor
speed-up.
+ "nohz/sched: delay going tickless when CPU is loaded" - http://lists.infradead.org/pipermail/linux-arm-kernel/2011-January/040165.html

One criterion of C-states selection is based on the load factor.  High
load prevents deep C-states.  The load is evaluated and updated at
each scheduler tick, and thus not updated when in tickless mode.  As a
result, the CPU load calculated on the tick just before entering
tickless is used for idle decisions.

When a high load is evaluated on a tick happening on a burst of
activity, this load value is kept until the next tick, which could
take few ms to happen if going tickless.

This patch ensures that the load is taken into consideration before
going tickless.  Rather than going tickless and entering a shallow
sleep state, the decison to go tickless is slightly delayed so that
the idle governor will tend to favor deeper sleep states.

Delaying NOHZ decisions until the load is zero improved the load
estimation on our ARM/OMAP4 platform where HZ =128 and increased the
time spent in deep C-states (~50% of idle time in C-states deeper than
C1).  A power saving of ~20mA at battery level is observed during MP3
playback on OMAP4/Blaze board.

Signed-off-by: Nicole Chalhoub <n-chalhoub at ti.com>
Signed-off-by: Vincent Bour <v-bour at ti.com>
Cc: Arjan van de Ven <arjan at linux.intel.com>
Cc: Thomas Gleixner <tglx at linutronix.de>
[khilman at ti.com: minor edits/changes to changelog]
Signed-off-by: Kevin Hilman <khilman at ti.com>

Conflicts:

	kernel/time/tick-sched.c
+ "network speed tweak" - https://github.com/ch33kybutt/i5700-kernel/commit/6a9403f22f87f602fe521cb34d55d9b862336c30 [do not merge]