Get rid of battd spam in log

This should fix the following lines in logs;
I/BATTD   (1304): BATTD: Read of Path /sys/class/power_supply/ac/model_name, Failed
I/BATTD   (1304): Could not open '/sys/class/power_supply/ac/model_name'

Patch by YetAnotherForumUser, thanks!

Change-Id: I90cb6fe1bb636f703d7fb4df0c9c53ae2a516246
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
cpufreq: interactive: add unregister_early_suspend

If suspend_enabled is set to 1 and the device screen goes off,
the device can't change the governor anymore.
This is probably due to the suspend/resume code, because with
suspend_enabled set to 0 it won't happen.

So the first idea is to unregister the suspend handler
once the governor exits.

Change-Id: I25b8cfedeb06a58cca25df4c42a151cb106763e5
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
cpufreq: ondemand: delete deprecated sampling_rate_max

Delete sampling_rate_max since its deprecated and
furthermore shows really funny values (tested with AeroControl)

Change-Id: I00286952f07d441b0160c6229bef71c1907ac853
Signed-off-by: Blechd0se <alex.christ@hotmail.de>
softirq: reduce latencies

In various network workloads, __do_softirq() latencies can be up
to 20 ms if HZ=1000, and 200 ms if HZ=100.

This is because we iterate 10 times in the softirq dispatcher,
and some actions can consume a lot of cycles.

This patch changes the fallback to ksoftirqd condition to :

- A time limit of 2 ms.
- need_resched() being set on current task

When one of this condition is met, we wakeup ksoftirqd for further
softirq processing if we still have pending softirqs.

Using need_resched() as the only condition can trigger RCU stalls,
as we can keep BH disabled for too long.

I ran several benchmarks and got no significant difference in
throughput, but a very significant reduction of latencies (one order
of magnitude) :

In following bench, 200 antagonist "netperf -t TCP_RR" are started in
background, using all available cpus.

Then we start one "netperf -t TCP_RR", bound to the cpu handling the NIC
IRQ (hard+soft)

Before patch :

# netperf -H 7.7.7.84 -t TCP_RR -T2,2 -- -k
RT_LATENCY,MIN_LATENCY,MAX_LATENCY,P50_LATENCY,P90_LATENCY,P99_LATENCY,MEAN_LATENCY,STDDEV_LATENCY
MIGRATED TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET
to 7.7.7.84 () port 0 AF_INET : first burst 0 : cpu bind
RT_LATENCY=550110.424
MIN_LATENCY=146858
MAX_LATENCY=997109
P50_LATENCY=305000
P90_LATENCY=550000
P99_LATENCY=710000
MEAN_LATENCY=376989.12
STDDEV_LATENCY=184046.92

After patch :

# netperf -H 7.7.7.84 -t TCP_RR -T2,2 -- -k
RT_LATENCY,MIN_LATENCY,MAX_LATENCY,P50_LATENCY,P90_LATENCY,P99_LATENCY,MEAN_LATENCY,STDDEV_LATENCY
MIGRATED TCP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET
to 7.7.7.84 () port 0 AF_INET : first burst 0 : cpu bind
RT_LATENCY=40545.492
MIN_LATENCY=9834
MAX_LATENCY=78366
P50_LATENCY=33583
P90_LATENCY=59000
P99_LATENCY=69000
MEAN_LATENCY=38364.67
STDDEV_LATENCY=12865.26

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Miller <davem@davemloft.net>
Cc: Tom Herbert <therbert@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cpufreq: interactive: disable suspend_enabled by default

Let the user decide if he wants to use it. Also change
the boostpulse_duration to 1 second.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>