From d283e80e93f47fd67c89599d2ebf6ba264c37586 Mon Sep 17 00:00:00 2001 From: Dietmar Eggemann Date: Fri, 30 Jun 2017 17:00:23 +0100 Subject: [PATCH] ANDROID: 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. Cc: Greg Kroah-Hartman Cc: Juri Lelli Signed-off-by: Dietmar Eggemann Change-Id: I7a0fadc160d85daf9e35e346391c5d0bb9167d71 Signed-off-by: Chris Redpath --- drivers/base/arch_topology.c | 14 ++++++++++++++ include/linux/arch_topology.h | 9 +++++++++ 2 files changed, 23 insertions(+) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index df2bab7de5db..06c8009cd000 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -22,6 +22,20 @@ #include #include +DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE; + +void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, + unsigned long max_freq) +{ + unsigned long scale; + int i; + + scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq; + + for_each_cpu(i, cpus) + per_cpu(freq_scale, i) = scale; +} + static DEFINE_MUTEX(cpu_scale_mutex); static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE; diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index d4fcb0efb896..f53438c77bf5 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -6,6 +6,7 @@ #define _LINUX_ARCH_TOPOLOGY_H_ #include +#include void topology_normalize_cpu_scale(void); @@ -17,4 +18,12 @@ 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_ */ -- 2.20.1