cpufreq interactive governor: event tracing

Change-Id: Ic13614a3da2faa2d4bd215ca3eb7191614f0cf66
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: apply intermediate load to max speed not current

Evaluate spikes in load (below go_hispeed_load) against the maximum
speed supported by the device, not the current speed (which tends to
make it too difficult to raise speed to intermediate levels until
very busy).

Change-Id: Ib937006abf8bedb60891a739acd733e89b732ae0
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: set at least hispeed when above hispeed load

If load is above go_hispeed_load, always go to at least hispeed_freq,
even when reducing speed from a higher speed, not just when jumping
up from minimum speed.  Avoids running at a lower than intended
speed after a burst of even higher load.

Change-Id: I5b9d2a15ba25ce609b21bac7c724265cf6838dee
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: don't drop speed if recently at higher load

Apply min_sample_time to the last time the current target speed
was originally requested or re-validated as appropriate for the
current load, not to the time since the current speed was
originally set.  Avoids periodic dips in speed during bursty
loads.

Change-Id: I250bda657985de60373f9897cc41f480664d51a1
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: configurable delay before raising above hispeed

Change-Id: I4d6ac40b23a3790d48e30c37408284e9f955e8fa
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: adjust code and documentation to match

Change-Id: If59c668d514a29febe5c35404fd9d01df8548eb1
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: based hispeed bump on target freq, not actual

For systems that set a common speed for all CPUs, checking current
speed here could bypass the intermediate hispeed bump decision for
this CPU when another CPU was already at hispeed.  This could
result in an overly high setting (for all CPUs) in situations
where all CPUs were about to drop to load levels that map to
hispeed or below.

Change-Id: I186f23dcfc5e2b6336cab8b0327f0c8a9a4482bc
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: Separate speed target revalidate time and initial set time

Allow speed drop after min_sample_time elapses from last time
the current speed was last re-validated as appropriate for
current load / input boost.

Allow speed bump after min_sample_time (or above_hispeed_delay)
elapses from the time the current speed was originally set.

Change-Id: Ic25687a7a53d25e6544c30c47d7ab6f27a47bee8
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: Boost frequency on touchscreen input

Based on previous patches by Tero Kristo <tero.kristo@nokia.com>,
Brian Steuer <bsteuer@codeaurora.org>,
David Ng <dave@codeaurora.org>,
Antti P Miettinen <amiettinen@nvidia.com>, and
Thomas Renninger <trenn@suse.de>

Change-Id: Ic55fedcf6f9310f43a7022fb88e23b0392122769
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: remove unused target_validate_time_in_idle

Change-Id: I37c5085b91318242612440dfd775ad762996612f
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: Add sysfs boost interface for hints from userspace

The explicit hint on/off version.

Change-Id: Ibf62b6d45bf6fb8c9c055b9bdaf074ce9374c04f
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: set floor for boosted speed

Allow speed to drop to flooor frequency but not below, don't pin
to speed at last boost.

Change-Id: I0147c2b7a2e61ba16820605af6baaf09570be787
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: add boost pulse interface

Change-Id: Icf1e86d2065cc8f0816ba9c6b065eb056d4e8249
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: restart above_hispeed_delay at each hispeed load

Change-Id: I2e5b91d45e8806b0ab94ca2301ed671c9af9ab13
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: Fix sysfs deadlock with concurrent hotplug/frequency switch

Running one program that continuously hotplugs and replugs a cpu
concurrently with another program that continuously writes to the
scaling_set_speed node eventually deadlocks with:

=============================================
[ INFO: possible recursive locking detected ]
3.4.0 #37 Tainted: G        W
---------------------------------------------
filemonkey/122 is trying to acquire lock:
 (s_active#13){++++.+}, at: [<c01a3d28>] sysfs_remove_dir+0x9c/0xb4

but task is already holding lock:
 (s_active#13){++++.+}, at: [<c01a22f0>] sysfs_write_file+0xe8/0x140

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(s_active#13);
  lock(s_active#13);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by filemonkey/122:
 #0:  (&buffer->mutex){+.+.+.}, at: [<c01a2230>] sysfs_write_file+0x28/0x140
 #1:  (s_active#13){++++.+}, at: [<c01a22f0>] sysfs_write_file+0xe8/0x140

stack backtrace:
[<c0014fcc>] (unwind_backtrace+0x0/0x120) from [<c00ca600>] (validate_chain+0x6f8/0x1054)
[<c00ca600>] (validate_chain+0x6f8/0x1054) from [<c00cb778>] (__lock_acquire+0x81c/0x8d8)
[<c00cb778>] (__lock_acquire+0x81c/0x8d8) from [<c00cb9c0>] (lock_acquire+0x18c/0x1e8)
[<c00cb9c0>] (lock_acquire+0x18c/0x1e8) from [<c01a3ba8>] (sysfs_addrm_finish+0xd0/0x180)
[<c01a3ba8>] (sysfs_addrm_finish+0xd0/0x180) from [<c01a3d28>] (sysfs_remove_dir+0x9c/0xb4)
[<c01a3d28>] (sysfs_remove_dir+0x9c/0xb4) from [<c02d0e5c>] (kobject_del+0x10/0x38)
[<c02d0e5c>] (kobject_del+0x10/0x38) from [<c02d0f74>] (kobject_release+0xf0/0x194)
[<c02d0f74>] (kobject_release+0xf0/0x194) from [<c0565a98>] (cpufreq_cpu_put+0xc/0x24)
[<c0565a98>] (cpufreq_cpu_put+0xc/0x24) from [<c05683f0>] (store+0x6c/0x74)
[<c05683f0>] (store+0x6c/0x74) from [<c01a2314>] (sysfs_write_file+0x10c/0x140)
[<c01a2314>] (sysfs_write_file+0x10c/0x140) from [<c014af44>] (vfs_write+0xb0/0x128)
[<c014af44>] (vfs_write+0xb0/0x128) from [<c014b06c>] (sys_write+0x3c/0x68)
[<c014b06c>] (sys_write+0x3c/0x68) from [<c000e0e0>] (ret_fast_syscall+0x0/0x3c)

This is because store() in cpufreq.c indirectly grabs a kobject
with kobject_get() and is the last one to call kobject_put()
indirectly via cpufreq_cpu_put().

Fix this deadlock by introducing two new functions,
cpufreq_cpu_get_sysfs() and cpufreq_cpu_put_sysfs() which do the
same thing as cpufreq_cpu_{get,put}() but don't grab the kobject.

CRs-fixed: 366560

Signed-off-by: Ramakrishna Prasad N <crpn@codeaurora.org>
(cherry picked from commit ddda0cf21dc6cb487aacd81fdb1a7343d2746d94)

Change-Id: I6ac89789e89099cff315d7a02de216423376b7f7
Signed-off-by: Shruthi Krishna <skrish@codeaurora.org>

Conflicts:

	drivers/cpufreq/cpufreq.c