From: Ionela Voinescu <ionela.voinescu@arm.com> To: Sudeep Holla <sudeep.holla@arm.com>, "Rafael J . Wysocki" <rjw@rjwysocki.net>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Giovanni Gherdovich <ggherdovich@suse.cz>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Valentin Schneider <valentin.schneider@arm.com> Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/3] arch_topology: obtain cpu capacity using information from CPPC Date: Fri, 14 May 2021 10:53:38 +0100 [thread overview] Message-ID: <20210514095339.12979-3-ionela.voinescu@arm.com> (raw) In-Reply-To: <20210514095339.12979-1-ionela.voinescu@arm.com> Define init_cpu_capacity_cppc() to use highest performance values from _CPC objects to obtain and set maximum capacity information for each CPU. acpi_cppc_processor_probe() is a good point at which to trigger the initialization of CPU (u-arch) capacity values, as at this point the highest performance values can be obtained from each CPU's _CPC objects. Architectures can therefore use this functionality through arch_init_invariance_cppc(). The performance scale used by CPPC is a unified scale for all CPUs in the system. Therefore, by obtaining the raw highest performance values from the _CPC objects, and normalizing them on the [0, 1024] capacity scale, used by the task scheduler, we obtain the CPU capacity of each CPU. While an ACPI Notify(0x85) could alert about a change in the highest performance value, which should in turn retrigger the CPU capacity computations, this notification is not currently handled by the ACPI processor driver. When supported, a call to arch_init_invariance_cppc() would perform the update. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> --- drivers/base/arch_topology.c | 39 +++++++++++++++++++++++++++++++++++ include/linux/arch_topology.h | 4 ++++ 2 files changed, 43 insertions(+) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index c1179edc0f3b..f710d64f125b 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -291,6 +291,45 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) return !ret; } +#ifdef CONFIG_ACPI_CPPC_LIB +#include <acpi/cppc_acpi.h> + +void init_cpu_capacity_cppc(void) +{ + struct cppc_perf_caps perf_caps; + int cpu; + + if (likely(acpi_disabled || !acpi_cpc_valid())) + return; + + raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity), + GFP_KERNEL); + if (!raw_capacity) + return; + + for_each_possible_cpu(cpu) { + if (!cppc_get_perf_caps(cpu, &perf_caps)) { + raw_capacity[cpu] = perf_caps.highest_perf; + pr_debug("%s: CPU%d cpu_capacity=%u (raw).\n", + __func__, cpu, raw_capacity[cpu]); + } else { + pr_err("%s: CPU%d missing highest performance.\n", + __func__, cpu); + pr_err("%s: fallback to 1024 for all CPUs\n", + __func__); + goto exit; + } + } + + topology_normalize_cpu_scale(); + schedule_work(&update_topology_flags_work); + pr_debug("%s: cpu_capacity initialization done\n", __func__); + +exit: + free_raw_capacity(); +} +#endif + #ifdef CONFIG_CPU_FREQ static cpumask_var_t cpus_to_visit; static void parsing_done_workfn(struct work_struct *work); diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index f180240dc95f..fbd829c3b7f7 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -11,6 +11,10 @@ void topology_normalize_cpu_scale(void); int topology_update_cpu_topology(void); +#ifdef CONFIG_ACPI_CPPC_LIB +void init_cpu_capacity_cppc(void); +#endif + struct device_node; bool topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu); -- 2.29.2.dirty
WARNING: multiple messages have this Message-ID (diff)
From: Ionela Voinescu <ionela.voinescu@arm.com> To: Sudeep Holla <sudeep.holla@arm.com>, "Rafael J . Wysocki" <rjw@rjwysocki.net>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Giovanni Gherdovich <ggherdovich@suse.cz>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Valentin Schneider <valentin.schneider@arm.com> Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/3] arch_topology: obtain cpu capacity using information from CPPC Date: Fri, 14 May 2021 10:53:38 +0100 [thread overview] Message-ID: <20210514095339.12979-3-ionela.voinescu@arm.com> (raw) In-Reply-To: <20210514095339.12979-1-ionela.voinescu@arm.com> Define init_cpu_capacity_cppc() to use highest performance values from _CPC objects to obtain and set maximum capacity information for each CPU. acpi_cppc_processor_probe() is a good point at which to trigger the initialization of CPU (u-arch) capacity values, as at this point the highest performance values can be obtained from each CPU's _CPC objects. Architectures can therefore use this functionality through arch_init_invariance_cppc(). The performance scale used by CPPC is a unified scale for all CPUs in the system. Therefore, by obtaining the raw highest performance values from the _CPC objects, and normalizing them on the [0, 1024] capacity scale, used by the task scheduler, we obtain the CPU capacity of each CPU. While an ACPI Notify(0x85) could alert about a change in the highest performance value, which should in turn retrigger the CPU capacity computations, this notification is not currently handled by the ACPI processor driver. When supported, a call to arch_init_invariance_cppc() would perform the update. Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> --- drivers/base/arch_topology.c | 39 +++++++++++++++++++++++++++++++++++ include/linux/arch_topology.h | 4 ++++ 2 files changed, 43 insertions(+) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index c1179edc0f3b..f710d64f125b 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -291,6 +291,45 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) return !ret; } +#ifdef CONFIG_ACPI_CPPC_LIB +#include <acpi/cppc_acpi.h> + +void init_cpu_capacity_cppc(void) +{ + struct cppc_perf_caps perf_caps; + int cpu; + + if (likely(acpi_disabled || !acpi_cpc_valid())) + return; + + raw_capacity = kcalloc(num_possible_cpus(), sizeof(*raw_capacity), + GFP_KERNEL); + if (!raw_capacity) + return; + + for_each_possible_cpu(cpu) { + if (!cppc_get_perf_caps(cpu, &perf_caps)) { + raw_capacity[cpu] = perf_caps.highest_perf; + pr_debug("%s: CPU%d cpu_capacity=%u (raw).\n", + __func__, cpu, raw_capacity[cpu]); + } else { + pr_err("%s: CPU%d missing highest performance.\n", + __func__, cpu); + pr_err("%s: fallback to 1024 for all CPUs\n", + __func__); + goto exit; + } + } + + topology_normalize_cpu_scale(); + schedule_work(&update_topology_flags_work); + pr_debug("%s: cpu_capacity initialization done\n", __func__); + +exit: + free_raw_capacity(); +} +#endif + #ifdef CONFIG_CPU_FREQ static cpumask_var_t cpus_to_visit; static void parsing_done_workfn(struct work_struct *work); diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index f180240dc95f..fbd829c3b7f7 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -11,6 +11,10 @@ void topology_normalize_cpu_scale(void); int topology_update_cpu_topology(void); +#ifdef CONFIG_ACPI_CPPC_LIB +void init_cpu_capacity_cppc(void); +#endif + struct device_node; bool topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu); -- 2.29.2.dirty _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-05-14 9:54 UTC|newest] Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-14 9:53 [PATCH 0/3] arch_topology, ACPI: populate cpu capacity from CPPC Ionela Voinescu 2021-05-14 9:53 ` Ionela Voinescu 2021-05-14 9:53 ` [PATCH 1/3] x86, ACPI: rename init_freq_invariance_cppc to arch_init_invariance_cppc Ionela Voinescu 2021-05-14 9:53 ` Ionela Voinescu 2021-05-14 9:53 ` Ionela Voinescu [this message] 2021-05-14 9:53 ` [PATCH 2/3] arch_topology: obtain cpu capacity using information from CPPC Ionela Voinescu 2021-05-14 16:16 ` Dietmar Eggemann 2021-05-14 16:16 ` Dietmar Eggemann 2021-05-19 9:46 ` Ionela Voinescu 2021-05-19 9:46 ` Ionela Voinescu 2021-05-18 13:12 ` Valentin Schneider 2021-05-18 13:12 ` Valentin Schneider 2021-05-14 9:53 ` [PATCH 3/3] arm64, topology: enable use of init_cpu_capacity_cppc() Ionela Voinescu 2021-05-14 9:53 ` Ionela Voinescu 2021-05-14 10:35 ` Catalin Marinas 2021-05-14 10:35 ` Catalin Marinas 2021-05-14 16:17 ` Dietmar Eggemann 2021-05-14 16:17 ` Dietmar Eggemann 2021-05-19 9:48 ` Ionela Voinescu 2021-05-19 9:48 ` Ionela Voinescu 2021-05-18 13:12 ` [PATCH 0/3] arch_topology, ACPI: populate cpu capacity from CPPC Valentin Schneider 2021-05-18 13:12 ` Valentin Schneider 2021-05-19 9:51 ` Ionela Voinescu 2021-05-19 9:51 ` Ionela Voinescu 2021-06-28 13:58 ` [tip: sched/core] sched/debug: Don't update sched_domain debug directories before sched_debug_init() tip-bot2 for Valentin Schneider
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