6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Vincent Guittot vincent.guittot@linaro.org
commit 1f023007f5e782bda19ad9104830c404fd622c5d upstream.
Use the new capacity_ref_freq() method to set the ratio that is used by AMU for computing the arch_scale_freq_capacity(). This helps to keep everything aligned using the same reference for computing CPUs capacity.
The default value of the ratio (stored in per_cpu(arch_max_freq_scale)) ensures that arch_scale_freq_capacity() returns max capacity until it is set to its correct value with the cpu capacity and capacity_ref_freq().
Signed-off-by: Vincent Guittot vincent.guittot@linaro.org Signed-off-by: Ingo Molnar mingo@kernel.org Acked-by: Sudeep Holla sudeep.holla@arm.com Acked-by: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/20231211104855.558096-8-vincent.guittot@linaro.org Stable-dep-of: e37617c8e53a ("sched/fair: Fix frequency selection for non-invariant case") Signed-off-by: Wentao Guan guanwentao@uniontech.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kernel/topology.c | 26 +++++++++++++------------- drivers/base/arch_topology.c | 12 +++++++++++- include/linux/arch_topology.h | 1 + 3 files changed, 25 insertions(+), 14 deletions(-)
--- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -82,7 +82,12 @@ int __init parse_acpi_topology(void) #undef pr_fmt #define pr_fmt(fmt) "AMU: " fmt
-static DEFINE_PER_CPU_READ_MOSTLY(unsigned long, arch_max_freq_scale); +/* + * Ensure that amu_scale_freq_tick() will return SCHED_CAPACITY_SCALE until + * the CPU capacity and its associated frequency have been correctly + * initialized. + */ +static DEFINE_PER_CPU_READ_MOSTLY(unsigned long, arch_max_freq_scale) = 1UL << (2 * SCHED_CAPACITY_SHIFT); static DEFINE_PER_CPU(u64, arch_const_cycles_prev); static DEFINE_PER_CPU(u64, arch_core_cycles_prev); static cpumask_var_t amu_fie_cpus; @@ -112,14 +117,14 @@ static inline bool freq_counters_valid(i return true; }
-static int freq_inv_set_max_ratio(int cpu, u64 max_rate, u64 ref_rate) +void freq_inv_set_max_ratio(int cpu, u64 max_rate) { - u64 ratio; + u64 ratio, ref_rate = arch_timer_get_rate();
if (unlikely(!max_rate || !ref_rate)) { - pr_debug("CPU%d: invalid maximum or reference frequency.\n", + WARN_ONCE(1, "CPU%d: invalid maximum or reference frequency.\n", cpu); - return -EINVAL; + return; }
/* @@ -139,12 +144,10 @@ static int freq_inv_set_max_ratio(int cp ratio = div64_u64(ratio, max_rate); if (!ratio) { WARN_ONCE(1, "Reference frequency too low.\n"); - return -EINVAL; + return; }
- per_cpu(arch_max_freq_scale, cpu) = (unsigned long)ratio; - - return 0; + WRITE_ONCE(per_cpu(arch_max_freq_scale, cpu), (unsigned long)ratio); }
static void amu_scale_freq_tick(void) @@ -195,10 +198,7 @@ static void amu_fie_setup(const struct c return;
for_each_cpu(cpu, cpus) { - if (!freq_counters_valid(cpu) || - freq_inv_set_max_ratio(cpu, - cpufreq_get_hw_max_freq(cpu) * 1000ULL, - arch_timer_get_rate())) + if (!freq_counters_valid(cpu)) return; }
--- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -344,6 +344,10 @@ bool __init topology_parse_cpu_capacity( return !ret; }
+void __weak freq_inv_set_max_ratio(int cpu, u64 max_rate) +{ +} + #ifdef CONFIG_ACPI_CPPC_LIB #include <acpi/cppc_acpi.h>
@@ -381,6 +385,9 @@ void topology_init_cpu_capacity_cppc(voi }
for_each_possible_cpu(cpu) { + freq_inv_set_max_ratio(cpu, + per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ); + capacity = raw_capacity[cpu]; capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT, capacity_scale); @@ -422,8 +429,11 @@ init_cpu_capacity_callback(struct notifi
cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus);
- for_each_cpu(cpu, policy->related_cpus) + for_each_cpu(cpu, policy->related_cpus) { per_cpu(capacity_freq_ref, cpu) = policy->cpuinfo.max_freq; + freq_inv_set_max_ratio(cpu, + per_cpu(capacity_freq_ref, cpu) * HZ_PER_KHZ); + }
if (cpumask_empty(cpus_to_visit)) { topology_normalize_cpu_scale(); --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -99,6 +99,7 @@ void update_siblings_masks(unsigned int void remove_cpu_topology(unsigned int cpuid); void reset_cpu_topology(void); int parse_acpi_topology(void); +void freq_inv_set_max_ratio(int cpu, u64 max_rate); #endif
#endif /* _LINUX_ARCH_TOPOLOGY_H_ */