Messages in this thread | | | From | Lukasz Luba <> | Subject | Re: [PATCH 4/4] powercap/drivers/dtpm: Add CPU energy model based support | Date | Tue, 10 Nov 2020 12:50:16 +0000 |
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On 10/6/20 1:20 PM, Daniel Lezcano wrote: > With the powercap dtpm controller, we are able to plug devices with > power limitation features in the tree. > > The following patch introduces the CPU power limitation based on the > energy model and the performance states. > > The power limitation is done at the performance domain level. If some > CPUs are unplugged, the corresponding power will be substracted from
s/substracted/subtracted
> the performance domain total power. > > It is up to the platform to initialize the dtpm tree and add the CPU. > > Here is an example to create a simple tree with one root node called > "pkg" and the cpu's performance domains.
s/cpu/CPU to be aligned with previous 'CPU'
> > int dtpm_register_pkg(struct dtpm_descr *descr) > { > struct dtpm *pkg; > int ret; > > pkg = dtpm_alloc(); > if (!pkg) > return -ENOMEM; > > ret = dtpm_register_parent(descr->name, pkg, descr->parent); > if (ret) > return ret; > > return dtpm_register_cpu(pkg); > } > > struct dtpm_descr descr = { > .name = "pkg", > .init = dtpm_register_pkg, > }; > DTPM_DECLARE(descr); > > Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> > --- > drivers/powercap/Kconfig | 8 ++ > drivers/powercap/Makefile | 1 + > drivers/powercap/dtpm_cpu.c | 242 ++++++++++++++++++++++++++++++++++++ > include/linux/cpuhotplug.h | 1 + > include/linux/dtpm.h | 3 + > 5 files changed, 255 insertions(+) > create mode 100644 drivers/powercap/dtpm_cpu.c > > diff --git a/drivers/powercap/Kconfig b/drivers/powercap/Kconfig > index 777cf60300b8..240dc09e8dc2 100644 > --- a/drivers/powercap/Kconfig > +++ b/drivers/powercap/Kconfig > @@ -49,4 +49,12 @@ config DTPM > help > This enables support for the power capping for the dynamic > thermal management userspace engine. > + > +config DTPM_CPU > + bool "Add CPU power capping based on the energy model" > + depends on DTPM && ENERGY_MODEL > + help > + This enables support for CPU power limitation based on > + energy model. > + > endif > diff --git a/drivers/powercap/Makefile b/drivers/powercap/Makefile > index 6482ac52054d..fabcf388a8d3 100644 > --- a/drivers/powercap/Makefile > +++ b/drivers/powercap/Makefile > @@ -1,5 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0-only > obj-$(CONFIG_DTPM) += dtpm.o > +obj-$(CONFIG_DTPM_CPU) += dtpm_cpu.o > obj-$(CONFIG_POWERCAP) += powercap_sys.o > obj-$(CONFIG_INTEL_RAPL_CORE) += intel_rapl_common.o > obj-$(CONFIG_INTEL_RAPL) += intel_rapl_msr.o > diff --git a/drivers/powercap/dtpm_cpu.c b/drivers/powercap/dtpm_cpu.c > new file mode 100644 > index 000000000000..23ebf704c599 > --- /dev/null > +++ b/drivers/powercap/dtpm_cpu.c > @@ -0,0 +1,242 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright 2020 Linaro Limited > + * > + * Author: Daniel Lezcano <daniel.lezcano@linaro.org> > + * > + */ > +#include <linux/cpumask.h> > +#include <linux/cpufreq.h> > +#include <linux/cpuhotplug.h> > +#include <linux/dtpm.h> > +#include <linux/energy_model.h> > +#include <linux/pm_qos.h> > +#include <linux/slab.h> > +#include <linux/units.h> > + > +static struct dtpm *__parent; > + > +static DEFINE_PER_CPU(struct dtpm *, dtpm_per_cpu); > + > +struct dtpm_cpu { > + struct freq_qos_request qos_req; > + int cpu; > +}; > + > +static int power_add(struct dtpm *dtpm, struct em_perf_domain *em) > +{ > + u64 power_min, power_max; > + > + power_min = em->table[0].power; > + power_min *= MICROWATT_PER_MILLIWATT; > + power_min += dtpm->power_min; > + > + power_max = em->table[em->nr_perf_states - 1].power; > + power_max *= MICROWATT_PER_MILLIWATT; > + power_max += dtpm->power_max; > + > + return dtpm_update_power(dtpm, power_min, power_max); > +} > + > +static int power_sub(struct dtpm *dtpm, struct em_perf_domain *em) > +{ > + u64 power_min, power_max; > + > + power_min = em->table[0].power; > + power_min *= MICROWATT_PER_MILLIWATT; > + power_min = dtpm->power_min - power_min; > + > + power_max = em->table[em->nr_perf_states - 1].power; > + power_max *= MICROWATT_PER_MILLIWATT; > + power_max = dtpm->power_max - power_max; > + > + return dtpm_update_power(dtpm, power_min, power_max); > +} > + > +static int set_pd_power_limit(struct powercap_zone *pcz, int cid, > + u64 power_limit) > +{ > + struct dtpm *dtpm = to_dtpm(pcz); > + struct dtpm_cpu *dtpm_cpu = dtpm->private; > + struct em_perf_domain *pd; > + unsigned long freq; > + int i, nr_cpus; > + > + spin_lock(&dtpm->lock); > + > + power_limit = clamp_val(power_limit, dtpm->power_min, dtpm->power_max); > + > + pd = em_cpu_get(dtpm_cpu->cpu); > + > + nr_cpus = cpumask_weight(to_cpumask(pd->cpus)); > + > + for (i = 0; i < pd->nr_perf_states; i++) { > + > + u64 power = pd->table[i].power * MICROWATT_PER_MILLIWATT; > + > + if ((power * nr_cpus) > power_limit) > + break; > + } > + > + freq = pd->table[i - 1].frequency; > + > + freq_qos_update_request(&dtpm_cpu->qos_req, freq); > + > + dtpm->power_limit = power_limit; > + > + spin_unlock(&dtpm->lock); > + > + return 0; > +} > + > +static int get_pd_power_limit(struct powercap_zone *pcz, int cid, u64 *data) > +{ > + struct dtpm *dtpm = to_dtpm(pcz); > + > + spin_lock(&dtpm->lock); > + *data = dtpm->power_max; > + spin_unlock(&dtpm->lock); > + > + return 0; > +} > + > +static int get_pd_power_uw(struct powercap_zone *pcz, u64 *power_uw) > +{ > + struct dtpm *dtpm = to_dtpm(pcz); > + struct dtpm_cpu *dtpm_cpu = dtpm->private; > + struct em_perf_domain *pd; > + unsigned long freq; > + int i, nr_cpus; > + > + freq = cpufreq_quick_get(dtpm_cpu->cpu); > + pd = em_cpu_get(dtpm_cpu->cpu); > + nr_cpus = cpumask_weight(to_cpumask(pd->cpus)); > + > + for (i = 0; i < pd->nr_perf_states; i++) { > + > + if (pd->table[i].frequency < freq) > + continue; > + > + *power_uw = pd->table[i].power * > + MICROWATT_PER_MILLIWATT * nr_cpus; > + > + return 0; > + } > + > + return -EINVAL; > +} > + > +static int cpu_release_zone(struct powercap_zone *pcz) > +{ > + struct dtpm *dtpm = to_dtpm(pcz); > + struct dtpm_cpu *dtpm_cpu = dtpm->private; > + > + freq_qos_remove_request(&dtpm_cpu->qos_req); > + > + return dtpm_release_zone(pcz);
The dtpm_cpu should be freed somewhere, maybe here or below.
> +} > + > +static struct powercap_zone_constraint_ops pd_constraint_ops = { > + .set_power_limit_uw = set_pd_power_limit, > + .get_power_limit_uw = get_pd_power_limit, > +}; > + > +static struct powercap_zone_ops pd_zone_ops = { > + .get_power_uw = get_pd_power_uw, > + .release = cpu_release_zone, > +}; > + > +static int cpuhp_dtpm_cpu_offline(unsigned int cpu) > +{ > + struct cpufreq_policy *policy; > + struct em_perf_domain *pd; > + struct dtpm *dtpm; > + > + policy = cpufreq_cpu_get(cpu); > + > + if (!policy) > + return 0; > + > + pd = em_cpu_get(cpu); > + if (!pd) > + return -EINVAL; > + > + dtpm = per_cpu(dtpm_per_cpu, cpu); > + > + power_sub(dtpm, pd); > + > + if (cpumask_weight(policy->cpus) != 1) > + return 0; > + > + for_each_cpu(cpu, policy->related_cpus) > + per_cpu(dtpm_per_cpu, cpu) = NULL; > + > + dtpm_unregister(dtpm);
Is it the right place to call kfree(dtpm_cpu)?
> + > + return 0; > +} > + > +static int cpuhp_dtpm_cpu_online(unsigned int cpu) > +{ > + struct dtpm *dtpm; > + struct dtpm_cpu *dtpm_cpu; > + struct cpufreq_policy *policy; > + struct em_perf_domain *pd; > + char name[CPUFREQ_NAME_LEN]; > + int ret; > + > + policy = cpufreq_cpu_get(cpu); > + > + if (!policy) > + return 0; > + > + pd = em_cpu_get(cpu); > + if (!pd) > + return -EINVAL; > + > + dtpm = per_cpu(dtpm_per_cpu, cpu); > + if (dtpm) > + return power_add(dtpm, pd); > + > + dtpm = dtpm_alloc(); > + if (!dtpm) > + return -EINVAL; > + > + dtpm_cpu = kzalloc(sizeof(dtpm_cpu), GFP_KERNEL);
We have to free this dtpm_cpu somewhere.
> + if (!dtpm_cpu) > + return -ENOMEM; > + > + dtpm->private = dtpm_cpu; > + dtpm_cpu->cpu = cpu; > + > + for_each_cpu(cpu, policy->related_cpus) > + per_cpu(dtpm_per_cpu, cpu) = dtpm; > + > + ret = power_add(dtpm, pd); > + if (ret) > + return ret; > + > + dtpm->power_limit = dtpm->power_max; > + > + sprintf(name, "cpu%d", dtpm_cpu->cpu); > + > + ret = dtpm_register(name, dtpm, __parent, &pd_zone_ops, > + 1, &pd_constraint_ops); > + if (ret) > + return ret; > + > + ret = freq_qos_add_request(&policy->constraints, > + &dtpm_cpu->qos_req, FREQ_QOS_MAX, > + pd->table[pd->nr_perf_states - 1].frequency); > + return ret; > +} > + > +int dtpm_register_cpu(struct dtpm *parent) > +{ > + __parent = parent; > + > + return cpuhp_setup_state(CPUHP_AP_DTPM_CPU_ONLINE, > + "dtpm_cpu:online", > + cpuhp_dtpm_cpu_online, > + cpuhp_dtpm_cpu_offline);
Shouldn't be the DTPM_CPU dependent on HOTPLUG_CPU in Kconfig? Most of platforms enable it by default, though.
> +} > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h > index bf9181cef444..6792bad4a435 100644 > --- a/include/linux/cpuhotplug.h > +++ b/include/linux/cpuhotplug.h > @@ -190,6 +190,7 @@ enum cpuhp_state { > CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30, > CPUHP_AP_X86_HPET_ONLINE, > CPUHP_AP_X86_KVM_CLK_ONLINE, > + CPUHP_AP_DTPM_CPU_ONLINE, > CPUHP_AP_ACTIVE, > CPUHP_ONLINE, > }; > diff --git a/include/linux/dtpm.h b/include/linux/dtpm.h > index 6696bdcfdb87..b62215a13baa 100644 > --- a/include/linux/dtpm.h > +++ b/include/linux/dtpm.h > @@ -70,4 +70,7 @@ int dtpm_register_parent(const char *name, struct dtpm *dtpm, > int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent, > struct powercap_zone_ops *ops, int nr_constraints, > struct powercap_zone_constraint_ops *const_ops); > + > +int dtpm_register_cpu(struct dtpm *parent); > +
This function needs a sibling under in #ifdef CONFIG_DTPM_CPU #else.
> #endif >
The code might a few print debugs which helps with experimenting.
In general, it looks good.
Regards, Lukasz
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