sched: remove one division operation in find_buiest_queue()

Date	Thu, 28 Mar 2013 16:58:52 +0900

Remove one division operation in find_buiest_queue().

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
sched: add PF_WAKE_UP_IDLE.

Certain workloads may benefit from the SD_SHARE_PKG_RESOURCES behavior
of waking their tasks up on idle CPUs. The feature has too much of a
negative impact on other workloads however to apply globally. The
PF_WAKE_UP_IDLE flag tells the scheduler to wake up tasks that have this
flag set, or tasks woken by tasks with this flag set, on an idle CPU
if one is available.

Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
(cherry picked from commit 500988016c53b675eae02401bd97462fed1737d6)

Change-Id: I6996afacecaec2959b84794eb032fe0a1ef2b3d7
Signed-off-by: Sudhir Sharma <sudsha@codeaurora.org>
sched: add sysctl for controlling task migrations on wake

The PF_WAKE_UP_IDLE per-task flag made it impossible to enable
the old behavior of SD_SHARE_PKG_RESOURCES, where every task
migrates to an idle CPU on wakeup.

The sched_wake_to_idle sysctl value, when made nonzero, will cause
all tasks to migrate to an idle CPU if one is available when the
task is woken up. This is regardless of how PF_WAKE_UP_IDLE is
configured for tasks in the system. Similar to PF_WAKE_UP_IDLE,
the SD_SHARE_PKG_RESOURCES scheduler domain flag must be enabled
for the sysctl value to have an effect.

Change-Id: I23bed846d26502c7aed600bfcf1c13053a7e5f61
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
(cherry picked from commit 9d5b38dc0025d19df5b756b16024b4269e73f282)
sched: introduce compute capacity for CPUs, groups and domains

Date	Tue, 16 Apr 2013 16:26:16 +0100

Using the per-cpu compute capacity exported from topology
when CONFIG_ARCH_SCALE_INVARIANT_CPU_CAPACITY is active, place this
information alongside cpu_power in the scheduler and combine for the
various aggregating entities.

Change-Id: I4984c335bcdc128680e7459b3f86bb05e04593cc
backported for Mako Hybrid from LKML

Signed-off-by: Paul Reioux <reioux@gmail.com>
sched: Scale load contribution by CPU Capacity

Date	Tue, 16 Apr 2013 16:26:35 +0100

Modulate the tracked load of a task using the measure of current
and maximum compute capacity for the core it is executing on.

Change-Id: If6aea806e631f2313fd925c8902260a522663dbd
backported for mako hybrid kernel from LKML

Signed-off-by: Paul Reioux <reioux@gmail.com>
Revert "sched: pack the idle load balance"

This reverts commit 53b48168e8a74b557a9fea0d87b6be6e7b506c7c.
sched: Remove stale power aware scheduling remnants and dysfunctional knobs

It's been broken forever (i.e. it's not scheduling in a power
aware fashion), as reported by Suresh and others sending
patches, and nobody cares enough to fix it properly ...
so remove it to make space free for something better.

There's various problems with the code as it stands today, first
and foremost the user interface which is bound to topology
levels and has multiple values per level. This results in a
state explosion which the administrator or distro needs to
master and almost nobody does.

Furthermore large configuration state spaces aren't good, it
means the thing doesn't just work right because it's either
under so many impossibe to meet constraints, or even if
there's an achievable state workloads have to be aware of
it precisely and can never meet it for dynamic workloads.

So pushing this kind of decision to user-space was a bad idea
even with a single knob - it's exponentially worse with knobs
on every node of the topology.

There is a proposal to replace the user interface with a single
3 state knob:

 sched_balance_policy := { performance, power, auto }

where 'auto' would be the preferred default which looks at things
like Battery/AC mode and possible cpufreq state or whatever the hw
exposes to show us power use expectations - but there's been no
progress on it in the past many months.

Aside from that, the actual implementation of the various knobs
is known to be broken. There have been sporadic attempts at
fixing things but these always stop short of reaching a mergable
state.

Therefore this wholesale removal with the hopes of spurring
people who care to come forward once again and work on a
coherent replacement.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1326104915.2442.53.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Paul Reioux <reioux@gmail.com>
Revert "sched: introduce compute capacity for CPUs, groups and domains"

This reverts commit 4a360316f925a8119a8489a6a3759c6216d1d949.