diff options
| author | Ionela Voinescu <ionela.voinescu@arm.com> | 2024-08-27 18:48:18 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2025-02-17 21:05:39 +0300 |
| commit | 004b500a9031973ba0d05edca860193f9a5938df (patch) | |
| tree | ed8150fc059ae4a5fef03c8204062105afe550b0 | |
| parent | 0ad2507d5d93f39619fc42372c347d6006b64319 (diff) | |
| download | linux-004b500a9031973ba0d05edca860193f9a5938df.tar.xz | |
arch_topology: init capacity_freq_ref to 0
It's useful to have capacity_freq_ref initialized to 0 for users of
arch_scale_freq_ref() to detect when capacity_freq_ref was not
yet set.
The only scenario affected by this change in the init value is when a
cpufreq driver is never loaded. As a result, the only setter of a
cpu scale factor remains the call of topology_normalize_cpu_scale()
from parse_dt_topology(). There we cannot use the value 0 of
capacity_freq_ref so we have to compensate for its uninitialized state.
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20240827154818.1195849-1-ionela.voinescu@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | drivers/base/arch_topology.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 3ebe77566788..8202447eb430 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -28,7 +28,7 @@ static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data); static struct cpumask scale_freq_counters_mask; static bool scale_freq_invariant; -DEFINE_PER_CPU(unsigned long, capacity_freq_ref) = 1; +DEFINE_PER_CPU(unsigned long, capacity_freq_ref) = 0; EXPORT_PER_CPU_SYMBOL_GPL(capacity_freq_ref); static bool supports_scale_freq_counters(const struct cpumask *cpus) @@ -293,13 +293,15 @@ void topology_normalize_cpu_scale(void) capacity_scale = 1; for_each_possible_cpu(cpu) { - capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu); + capacity = raw_capacity[cpu] * + (per_cpu(capacity_freq_ref, cpu) ?: 1); capacity_scale = max(capacity, capacity_scale); } pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale); for_each_possible_cpu(cpu) { - capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu); + capacity = raw_capacity[cpu] * + (per_cpu(capacity_freq_ref, cpu) ?: 1); capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT, capacity_scale); topology_set_cpu_scale(cpu, capacity); |