sched/debug: disable sched debug sysrq by default - increase performance

Signed-off-by: poondog <markj338@gmail.com>
DRIVERS: MEDIA: removing media_tuner

Signed-off-by: poondog <markj338@gmail.com>
AIO: Don't plug the I/O queue in do_io_submit()

Asynchronous I/O latency to a solid-state disk greatly increased between the
2.6.32 and 3.0 kernels. By removing the plug from do_io_submit(), we observed
a 34% improvement in the I/O latency.

Unfortunately, at this level, we don't know if the request is to
a rotating disk or not.

Change-Id: I7101df956473ed9fd5dcff18e473dd93b688a5c1
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: linux-aio@kvack.org
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: poondog <markj338@gmail.com>
INCLUDE: LOAD_FREQ avoids loadavg Moire

LOAD_FREQ is (5*HZ+1) to avoid high load average when idle:
http://kerneltrap.org/mailarchive/linux-kernel/2007/10/3/328568

I suggest (4*HZ+61) for a better distribution.

With some seconds based load (like SSL heartbeats)
and LOAD_FREQ at (5*HZ+1) I see Moire patterns like inverse sawtooth,
since 2 or 3 probes hit the jobs (load increases quickly),
followed by several probes missing it.

A 4.61 sec interval gives optimal distribution over when within a
second a probe is taken, as .61 is close to golden ratio phi 1.618...
(test in http://ripke.com/goldenratio.c).

12*4.61 = 55.32 secs is still close to a minute,
and 13*4.61=59.93 is even closer than the current 12*5.01=60.12
(with exponents EXP_x adjusted to a ratio of 13 instead of 12).

best
Klaus

(Klaus Ripke)

Signed-off-by: poondog <markj338@gmail.com>
xsched: Optimize build_sched_domains() for saving first SD node for a cpu

Backport:

We are saving first scheduling domain for a cpu in build_sched_domains() by
iterating over the nested sd->child list. We don't actually need to do it this
way.

tl will be equal to sched_domain_topology for the first iteration and so we can
set *per_cpu_ptr(d.sd, i) based on that.  So, save pointer to first SD while
running the iteration loop over tl's.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/fc473527cbc4dfa0b8eeef2a59db74684eb59a83.1370436120.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: poondog <markj338@gmail.com>
msm: acpuclock-krait: Inline some functions

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: poondog <markj338@gmail.com>