Revert "cpufreq: interactive: Fix null pointer dereference in interactive governor"

This reverts commit 6d1dfa72285deb433f208c8557a60a558ff0c29e.
Revert "cpufreq: Fix broken uevents for cpufreq governor and cpu devices"

This reverts commit 99883b3d9331666b07af0361638c6f364b514d40.
sched/fair: Optimize find_busiest_queue()

Use for_each_cpu_and() and thereby avoid computing the capacity for
CPUs we know we're not interested in.

Reviewed-by: Paul Turner <pjt@google.com>
Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-lppceyv6kb3a19g8spmrn20b@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul Reioux <reioux@gmail.com>

backported for Linux 3.4

Conflicts:
	kernel/sched/fair.c
sched/fair: Optimize cgroup pick_next_task_fair()

Since commit 2f36825b1 ("sched: Next buddy hint on sleep and preempt
path") it is likely we pick a new task from the same cgroup, doing a put
and then set on all intermediate entities is a waste of time, so try to
avoid this.

Measured using:

  mount nodev /cgroup -t cgroup -o cpu
  cd /cgroup
  mkdir a; cd a
  mkdir b; cd b
  mkdir c; cd c
  echo $$ > tasks
  perf stat --repeat 10 -- taskset 1 perf bench sched pipe

PRE :      4.542422684 seconds time elapsed   ( +-  0.33% )
POST:      4.389409991 seconds time elapsed   ( +-  0.32% )

Which shows a significant improvement of ~3.5%

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul Reioux <reioux@gmail.com>

Backported for Linux 3.4 kernel

Conflicts:
	kernel/sched/fair.c
sched/fair: improve fairness efficiency

Measured using hackbench:

PRE-patch :      4.542422684 seconds time elapsed   ( +-  47.40% )
POST-page :      2.389409991 seconds time elapsed   ( +-  47.40% )

Which shows a significant improvement of ~47.40%

Signed-off-by: Paul Reioux <reioux@gmail.com>
CK3 tweaks (Credits to Con Kolivas)

* mm-enable_swaptoken_only_when_swap_full.patch:
  The swap token is only useful in conditions of swap thrash, and actually
  worsens the common case by causing more swapping. Make it only have an effect
  when swap is more than half full.

* mm-drop_swap_cache_aggressively.patch:
  While it may be nice to have a copy of pages on swap once written there, the
  more garbage we leave in the swapspace the slower any further writes and
  reads to and from it are. Just free swapcache whenever we can.

* mm-kswapd_inherit_prio-1.patch:
  When kswapd is awoken due to reclaim by a running task, set the priority of
  kswapd to that of the calling task thus making memory reclaim cpu activity
  affected by nice level.

* hz-default_1000.patch:
  Set default HZ to 1000 which is what most desktop users should still be using.

* hz-no_default_250.patch:
  Make 250HZ not be the default to discourage desktop users from choosing this
  option since 1000 will provide better latencies with only miniscule amounts
  of extra overhead and power consumption.

* preempt-desktop-tune.patch:
  Enable preempt by default and make people steer away from voluntary.
set HZ=1000 (exp)