diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-05-06 22:41:21 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-05-13 14:34:18 +0200 |
| commit | 4a6b1cf0d4c02d6da2976c6314c264d20672937e (patch) | |
| tree | b19acfc7956949665e122e45282ff376bdd41bee | |
| parent | 3e3ba654d3097e0031f2add215b12ff81c23814e (diff) | |
PM: EM: Introduce em_adjust_cpu_capacity()
Add a function for updating the Energy Model for a CPU after its
capacity has changed, which subsequently will be used by the
intel_pstate driver.
An EM_PERF_DOMAIN_ARTIFICIAL check is added to em_recalc_and_update()
to prevent it from calling em_compute_costs() for an "artificial" perf
domain with a NULL cb parameter which would cause it to crash.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://patch.msgid.link/3637203.iIbC2pHGDl@rjwysocki.net
| -rw-r--r-- | include/linux/energy_model.h | 2 | ||||
| -rw-r--r-- | kernel/power/energy_model.c | 28 |
2 files changed, 26 insertions, 4 deletions
diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index d8eabbf86a5b..7fa1eb3cc823 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -179,6 +179,7 @@ int em_dev_compute_costs(struct device *dev, struct em_perf_state *table, int em_dev_update_chip_binning(struct device *dev); int em_update_performance_limits(struct em_perf_domain *pd, unsigned long freq_min_khz, unsigned long freq_max_khz); +void em_adjust_cpu_capacity(unsigned int cpu); void em_rebuild_sched_domains(void); /** @@ -403,6 +404,7 @@ int em_update_performance_limits(struct em_perf_domain *pd, { return -EINVAL; } +static inline void em_adjust_cpu_capacity(unsigned int cpu) {} static inline void em_rebuild_sched_domains(void) {} #endif diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c index 88449d4390cb..ea7995a25780 100644 --- a/kernel/power/energy_model.c +++ b/kernel/power/energy_model.c @@ -702,10 +702,12 @@ static int em_recalc_and_update(struct device *dev, struct em_perf_domain *pd, { int ret; - ret = em_compute_costs(dev, em_table->state, NULL, pd->nr_perf_states, - pd->flags); - if (ret) - goto free_em_table; + if (!em_is_artificial(pd)) { + ret = em_compute_costs(dev, em_table->state, NULL, + pd->nr_perf_states, pd->flags); + if (ret) + goto free_em_table; + } ret = em_dev_update_perf_domain(dev, em_table); if (ret) @@ -755,6 +757,24 @@ static void em_adjust_new_capacity(unsigned int cpu, struct device *dev, em_recalc_and_update(dev, pd, em_table); } +/** + * em_adjust_cpu_capacity() - Adjust the EM for a CPU after a capacity update. + * @cpu: Target CPU. + * + * Adjust the existing EM for @cpu after a capacity update under the assumption + * that the capacity has been updated in the same way for all of the CPUs in + * the same perf domain. + */ +void em_adjust_cpu_capacity(unsigned int cpu) +{ + struct device *dev = get_cpu_device(cpu); + struct em_perf_domain *pd; + + pd = em_pd_get(dev); + if (pd) + em_adjust_new_capacity(cpu, dev, pd); +} + static void em_check_capacity_update(void) { cpumask_var_t cpu_done_mask; |