Re: [PATCH v4 6/7] arm64: use activity monitors for frequency invariance
From: Valentin Schneider <hidden>
Date: 2020-02-24 18:40:45
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Ionela Voinescu writes:
Signed-off-by: Ionela Voinescu <redacted> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Sudeep Holla <redacted>
With the small nits below: Reviewed-by: Valentin Schneider <redacted>
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index fa9528dfd0ce..7606cbd63517 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c + +static inline int
That should be bool, seeing what it returns.
quoted hunk ↗ jump to hunk
+enable_policy_freq_counters(int cpu, cpumask_var_t valid_cpus) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); + + if (!policy) { + pr_debug("CPU%d: No cpufreq policy found.\n", cpu); + return false; + } + + if (cpumask_subset(policy->related_cpus, valid_cpus)) + cpumask_or(amu_fie_cpus, policy->related_cpus, + amu_fie_cpus); + + cpufreq_cpu_put(policy); + + return true; +}diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 1eb81f113786..1ab2b7503d63 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c@@ -29,6 +29,14 @@ void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, unsigned long scale; int i; + /* + * If the use of counters for FIE is enabled, just return as we don't + * want to update the scale factor with information from CPUFREQ. + * Instead the scale factor will be updated from arch_scale_freq_tick. + */ + if (arch_cpu_freq_counters(cpus)) + return; + scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq; for_each_cpu(i, cpus)diff --git a/include/linux/topology.h b/include/linux/topology.h index eb2fe6edd73c..397aad6ae163 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h@@ -227,5 +227,12 @@ static inline const struct cpumask *cpu_cpu_mask(int cpu) return cpumask_of_node(cpu_to_node(cpu)); } +#ifndef arch_cpu_freq_counters +static __always_inline +bool arch_cpu_freq_counters(struct cpumask *cpus) +{ + return false; +} +#endif
Apologies for commenting on this only now, I had missed it in my earlier round of review. I would've liked to keep this contained within arm64 stuff until we agreed on a more generic counter-driven FIE interface, but seems like we can't evade it due to the arch_topology situation. Would it make sense to relocate this stub to arch_topology.h instead, at least for the time being? That way the only non-arm64 changes are condensed in arch_topology (even if it doesn't change much in terms of header files, since topology.h imports arch_topology.h)
#endif /* _LINUX_TOPOLOGY_H */
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