hashtable: introduce a small and naive hashtable

This hashtable implementation is using hlist buckets to provide a simple
hashtable to prevent it from getting reimplemented all over the kernel.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
[ Merging this now, so that subsystems can start applying Sasha's
  patches that use this   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
block,elevator: use new hashtable implementation

Switch elevator to use the new hashtable implementation. This reduces the
amount of generic unrelated code in the elevator.

This also removes the dymanic allocation of the hash table. The size of the table is
constant so there's no point in paying the price of an extra dereference when accessing
it.

This patch depends on d9b482c ("hashtable: introduce a small and naive
hashtable") which was merged in v3.6.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
FS: import F2FS

Signed-off-by: Paul Reioux <reioux@gmail.com>
f2fs: data: AIO optimization compatibility fixup

Signed-off-by: Paul Reioux <reioux@gmail.com>
lowmemorykiller: make default lowmemorykiller debug message useful

lowmemorykiller debug messages are inscrutable and mostly useful
for debugging the lowmemorykiller, not explaining why a process
was killed.  Make the messages more useful by prefixing them
with "lowmemorykiller: " and explaining in more readable terms
what was killed, who it was killed for, and why it was killed.

The messages now look like:
[   76.997631] lowmemorykiller: Killing 'droid.gallery3d' (2172), adj 1000,
[   76.997635]    to free 27436kB on behalf of 'kswapd0' (29) because
[   76.997638]    cache 122624kB is below limit 122880kB for oom_score_adj 1000
[   76.997641]    Free memory is -53356kB above reserved

A negative number for free memory above reserved means some of the
reserved memory has been used and is being regenerated by kswapd,
which is likely what called the shrinkers.

Change-Id: I1fe983381e73e124b90aa5d91cb66e55eaca390f
Signed-off-by: Colin Cross <ccross@android.com>
staging: android: lowmemorykiller: Management of not killable processes

This feature allows the user to define processes and system processes
white-lists filled with the preferred process names and to not be killed
by lowmemorykiller, unless it is absolutely necessary.

This feature exposes four new lowmemorykiller parameters:
- donotkill_proc, is the flag to enable / disable this feature for the
  processes chosen by the user
- donotkill_sysproc, is the flag to enable / disable this feature for the
  system processes chosen by the user
- donotkill_proc_names, is the list of process names (comma separated)
  chosen by the user to be preserved from killing
- donotkill_sysproc_names, is the list of user system process names (comma separated)
  chosen by the user to be preserved from killing

When a the lowmemorykiller needs to free ram, it will first kill the processes
not included inside the two process name lists chosen by the user.
If there are no more standard killable processes, then it will be necessary to
kill one of the processes included inside one of the two white-lists, to
prevent system hangs, slowdowns, etc.

Conflicts:
	drivers/staging/android/lowmemorykiller.c
Revert all interactive patches
cpufreq: Sync on thread migration optimizations

When threads migrate between CPUs the destination CPU will temporarily
have a boosted frequency and the source CPU will have a residual higher
frequency even though the load could have just been reduced. To avoid
leaving CPUs at a high frequencies notify the source CPU after a thread
migration and make the interactive governor's timer reschedule
conditionally.

Change-Id: Id55055f2a116ca7ffd2a34dc3d0ec519c888a111
Signed-off-by: Patrick Cain <pcain@codeaurora.org>

Conflicts:
	drivers/cpufreq/cpu-boost.c
cpufreq: interactive: Don't reset sampling down factor at max freq

A previous patch sets the min_sample_time to zero if the cpufreq
min/max limits have changed which would bring down the frequency
in the next sample even if min_sample_time doesnt allow it to do so.
This could severly affect benchmarks if this is applied to max
frequencies as min_sample_time for max frequencies is set to
sampling_down_factor.
This patch resets the limits_changed flag for cases where timer fires
while running at max frequencies so that sampling_down_factor is
still applicable as before.

Change-Id: I397133cb15eea4ab999d0f69617b4922438c6e11
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
cpufreq: interactive: Remove unnecessary cpu_online() check

Cpufreq no longer calls governor callback for offlined cpus. i.e. All
policy->cpus are guaranteed to be online. Hence we don't need explicit check to
see if cpu is online or not.

Change-Id: I9ad85ea4addd5b4a40952e59ed730dd15e328690
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
cpufreq: cpu-boost: Re-issue boosts above minimum frequency

Frequency boosts where the source CPU frequency is greater than CPU's
minimum frequency should always go through regardless of the destination
CPU's current frequency. This fixes a performance issue where the governor
lowers the CPU frequency shortly after a thread is migrated to it because
the boost wasn't re-issued.

Change-Id: I449545a688d84b0a6e834f5a51dcb499caa84d29
Signed-off-by: Patrick Cain <pcain@codeaurora.org>
Revert all cpu freq changes
cpufreq: force cpuN policy to match cpu0 when changing freq or gov
msm: cpufreq: set to info level freq limits routine
Revert "msm: cpufreq: set to info level freq limits routine"

This reverts commit e60ad2c4011efb5485c8d9003285431235a9a74f.
msm: cpufreq: Break out early if target frequency is the same as the current

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
cpufreq: Save user policy min/max instead of policy min/max during hotplug

When a CPU is hotplugged off, various fields of the policy are saved so
that they can be restored when the CPU is hotplugged back in.

The existing code saves the policy min/max field during hotplug remove and
restores it into user policy min/max during hotplug add. This results in
the loss of the user policy min/max values across a hotplug remove/add.

Fix it by saving the user policy min/max instead of policy min/max during
hotplug remove. During a hotplug add, after user policy min/max is
restored, the policy min/max is already recomputed. So, there's no risk of
going beyound any limits imposed by the CPUFREQ_ADJUST/INCOMPATIBLE
notifiers.

Change-Id: Ib8e09fa324c1f80f095c5754b5dcf2685e8e4a66
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
cpufreq: interactive: fix compiling warnings with new toolchain 4.9
cpufreq: interactive: turn boost_pulse off on boost off

Change-Id: I36fe217fa047d68ea90e78b12c7db4537ea8010b
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
cpufreq: interactive: Optimize sync_freq implementation

Don't let frequency drop below sync_freq if either load or
frequency among other cpus is above a certain threshold,
not necessarily both.