drivers base/arch_topology: provide frequency-invariant accounting support

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Implements the arch-specific (arm and arm64) frequency-invariance setter
function arch_set_freq_scale() which provides the following frequency
scaling factor:

  current_freq(cpu) << SCHED_CAPACITY_SHIFT / max_supported_freq(cpu)

One possible consumer of the frequency-invariance getter function
topology_get_freq_scale() is the Per-Entity Load Tracking (PELT)
mechanism of the task scheduler.

Allow inlining of topology_get_freq_scale() into the task scheduler
fast path (e.g. __update_load_avg_se()) by coding it as a static inline
function in the arch topology header file.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

...

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Dietmar Eggemann 2017-09-26 17:41:10 +01:00 • committed by Rafael J. Wysocki

parent 400ec74d3b

commit 0e27c567d1

2 changed files with 23 additions and 0 deletions

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14

drivers/base/arch_topology.c

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9

include/linux/arch_topology.h

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