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| author |   Dietmar Eggemann <dietmar.eggemann@arm.com> | 2017-09-26 17:41:10 +0100 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-10-03 02:37:53 +0200 |
| commit | 0e27c567d1673137b06aa96bb7aef635fb657dee (patch) | |
| tree | bcbb7041ef1af0a73336595a4e9d72ec5fedb813 /include/linux/arch_topology.h | |
| parent | cpufreq: dt: invoke frequency-invariance setter function (diff) | |
| download | linux-dev-0e27c567d1673137b06aa96bb7aef635fb657dee.tar.xz linux-dev-0e27c567d1673137b06aa96bb7aef635fb657dee.zip | |
drivers base/arch_topology: provide frequency-invariant accounting support
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>
Diffstat (limited to 'include/linux/arch_topology.h')
| -rw-r--r-- | include/linux/arch_topology.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index 716ce587247e..f6e490312e4d 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -5,6 +5,7 @@ #define _LINUX_ARCH_TOPOLOGY_H_ #include <linux/types.h> +#include <linux/percpu.h> void topology_normalize_cpu_scale(void); @@ -16,4 +17,12 @@ unsigned long topology_get_cpu_scale(struct sched_domain *sd, int cpu); void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity); +DECLARE_PER_CPU(unsigned long, freq_scale); + +static inline +unsigned long topology_get_freq_scale(struct sched_domain *sd, int cpu) +{ + return per_cpu(freq_scale, cpu); +} + #endif /* _LINUX_ARCH_TOPOLOGY_H_ */ |