Steve Muckle f49a1d8ca7 BACKPORT: cpufreq: schedutil: New governor based on scheduler utilization data ... Add a new cpufreq scaling governor, called "schedutil", that uses scheduler-provided CPU utilization information as input for making its decisions. Doing that is possible after commit 34e2c55 (cpufreq: Add mechanism for registering utilization update callbacks) that introduced cpufreq_update_util() called by the scheduler on utilization changes (from CFS) and RT/DL task status updates. In particular, CPU frequency scaling decisions may be based on the the utilization data passed to cpufreq_update_util() by CFS. The new governor is relatively simple. The frequency selection formula used by it depends on whether or not the utilization is frequency-invariant. In the frequency-invariant case the new CPU frequency is given by next_freq = 1.25 * max_freq * util / max where util and max are the last two arguments of cpufreq_update_util(). In turn, if util is not frequency-invariant, the maximum frequency in the above formula is replaced with the current frequency of the CPU: next_freq = 1.25 * curr_freq * util / max The coefficient 1.25 corresponds to the frequency tipping point at (util / max) = 0.8. All of the computations are carried out in the utilization update handlers provided by the new governor. One of those handlers is used for cpufreq policies shared between multiple CPUs and the other one is for policies with one CPU only (and therefore it doesn't need to use any extra synchronization means). The governor supports fast frequency switching if that is supported by the cpufreq driver in use and possible for the given policy. In the fast switching case, all operations of the governor take place in its utilization update handlers. If fast switching cannot be used, the frequency switch operations are carried out with the help of a work item which only calls __cpufreq_driver_target() (under a mutex) to trigger a frequency update (to a value already computed beforehand in one of the utilization update handlers). Currently, the governor treats all of the RT and DL tasks as "unknown utilization" and sets the frequency to the allowed maximum when updated from the RT or DL sched classes. That heavy-handed approach should be replaced with something more subtle and specifically targeted at RT and DL tasks. The governor shares some tunables management code with the "ondemand" and "conservative" governors and uses some common definitions from cpufreq_governor.h, but apart from that it is stand-alone. Change-Id: I03876e622768e4b3ee4dc28682af7cce771f2f4c Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> (cherry-picked from 9bdcb44e39) [ Backport the schedutil cpufreq governor from 4.9. Some cpufreq tunable infrastructure as well as the resolve_freq API is also backported as those are dependencies] Signed-off-by: Steve Muckle <smuckle@linaro.org> [trivial cherry-picking fixes] Signed-off-by: Juri Lelli <juri.lelli@arm.com> [fixed default governor machinery] Signed-off-by: Chris Redpath <chris.redpath@arm.com>		2017-06-21 16:34:04 +05:30
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acpi
asm-generic	UPSTREAM: mm: add PHYS_PFN, use it in __phys_to_pfn()	2017-04-10 13:23:34 +05:30
clocksource	arm64: KVM: Implement timer save/restore	2016-11-09 22:15:41 +08:00
crypto	Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android	2017-04-23 12:02:14 +08:00
drm	drm/ttm, drm/vmwgfx: Relax permission checking when opening surfaces	2017-04-12 12:38:33 +02:00
dt-bindings
keys
kvm	KVM: arm/arm64: vgic-v3: Make the LR indexing macro public	2016-11-09 22:15:40 +08:00
linux	BACKPORT: cpufreq: schedutil: New governor based on scheduler utilization data	2017-06-21 16:34:04 +05:30
math-emu
media	videobuf2-core: Check user space planes array in dqbuf	2016-05-04 14:48:50 -07:00
memory
misc
net	Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android	2017-06-08 12:11:52 +08:00
pcmcia
ras
rdma	RDMA/core: Fix incorrect structure packing for booleans	2017-03-12 06:37:29 +01:00
rxrpc
scsi	scsi: libiscsi: add lock around task lists to fix list corruption regression	2017-03-26 12:13:19 +02:00
soc	ARM: at91: define LPDDR types	2017-03-12 06:37:24 +01:00
sound	ALSA: rawmidi: Make snd_rawmidi_transmit() race-free	2016-02-17 12:30:58 -08:00
target	target: Convert ACL change queue_depth se_session reference usage	2017-05-20 14:26:58 +02:00
trace	ANDROID: Replace spaces by '_' for some android filesystem tracepoints.	2017-04-10 13:12:16 +05:30
uapi	Merge remote-tracking branch 'lts/linux-4.4.y' into linux-linaro-lsk-v4.4	2017-05-15 17:31:58 +08:00
video	Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android	2016-06-14 17:08:03 +08:00
xen	xen: Fix page <-> pfn conversion on 32 bit systems	2016-05-11 11:21:14 +02:00
Kbuild