From: Tianyang Zhang <zhangtianyang@loongson.cn> LoongArch inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IC6CVG CVE: NA -------------------------------- In order to achieve more reasonable load balancing behavior, add SCHED_MC (Multi-core scheduler) support. The LLC distribution of LoongArch now is consistent with NUMA node, the balancing domain of SCHED_MC can effectively reduce the situation where processes are awakened to smt_sibling. Co-developed-by: Hongliang Wang <wanghongliang@loongson.cn> Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn> Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn> --- arch/loongarch/Kconfig | 9 +++++++ arch/loongarch/include/asm/smp.h | 1 + arch/loongarch/include/asm/topology.h | 9 +++++++ arch/loongarch/kernel/smp.c | 38 +++++++++++++++++++++++++++ 4 files changed, 57 insertions(+) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index fa47efea7a13..8739e15c137b 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -420,6 +420,15 @@ config SCHED_SMT Improves scheduler's performance when there are multiple threads in one physical core. +config SCHED_MC + bool "Multi-core scheduler support" + depends on SMP + default y + help + Multi-core scheduler support improves the CPU scheduler's decision + making when dealing with multi-core CPU chips at a cost of slightly + increased overhead in some places. + config SMP bool "Multi-Processing support" help diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/smp.h index cc232901e4dd..401be3a7a763 100644 --- a/arch/loongarch/include/asm/smp.h +++ b/arch/loongarch/include/asm/smp.h @@ -23,6 +23,7 @@ extern int smp_num_siblings; extern int num_processors; extern int disabled_cpus; extern cpumask_t cpu_sibling_map[]; +extern cpumask_t cpu_llc_shared_map[]; extern cpumask_t cpu_core_map[]; extern cpumask_t cpu_foreign_map[]; diff --git a/arch/loongarch/include/asm/topology.h b/arch/loongarch/include/asm/topology.h index 379f5e4830eb..3b21a6d4f522 100644 --- a/arch/loongarch/include/asm/topology.h +++ b/arch/loongarch/include/asm/topology.h @@ -30,6 +30,15 @@ void numa_set_distance(int from, int to, int distance); #ifdef CONFIG_SMP extern unsigned int __max_packages; + +/* + * Return cpus that shares the last level cache. + */ +static inline const struct cpumask *cpu_coregroup_mask(int cpu) +{ + return &cpu_llc_shared_map[cpu]; +} + #define topology_max_packages() (__max_packages) #define topology_physical_package_id(cpu) (cpu_data[cpu].package) #define topology_core_id(cpu) (cpu_data[cpu].core) diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c index 5d02bf5126b7..6773e19e669a 100644 --- a/arch/loongarch/kernel/smp.c +++ b/arch/loongarch/kernel/smp.c @@ -45,6 +45,10 @@ EXPORT_SYMBOL(__cpu_logical_map); cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly; EXPORT_SYMBOL(cpu_sibling_map); +/* Representing the last level cache shared map of each logical CPU */ +cpumask_t cpu_llc_shared_map[NR_CPUS] __read_mostly; +EXPORT_SYMBOL(cpu_llc_shared_map); + /* Representing the core map of multi-core chips of each logical CPU */ cpumask_t cpu_core_map[NR_CPUS] __read_mostly; EXPORT_SYMBOL(cpu_core_map); @@ -62,6 +66,9 @@ EXPORT_SYMBOL(cpu_foreign_map); /* representing cpus for which sibling maps can be computed */ static cpumask_t cpu_sibling_setup_map; +/* representing cpus for which llc shared maps can be computed */ +static cpumask_t cpu_llc_shared_setup_map; + /* representing cpus for which core maps can be computed */ static cpumask_t cpu_core_setup_map; @@ -103,6 +110,34 @@ static inline void set_cpu_core_map(int cpu) } } +static inline void set_cpu_llc_shared_map(int cpu) +{ + int i; + + cpumask_set_cpu(cpu, &cpu_llc_shared_setup_map); + + for_each_cpu(i, &cpu_llc_shared_setup_map) { + if (cpu_to_node(cpu) == cpu_to_node(i)) { + cpumask_set_cpu(i, &cpu_llc_shared_map[cpu]); + cpumask_set_cpu(cpu, &cpu_llc_shared_map[i]); + } + } +} + +static inline void clear_cpu_llc_shared_map(int cpu) +{ + int i; + + for_each_cpu(i, &cpu_llc_shared_setup_map) { + if (cpu_to_node(cpu) == cpu_to_node(i)) { + cpumask_clear_cpu(i, &cpu_llc_shared_map[cpu]); + cpumask_clear_cpu(cpu, &cpu_llc_shared_map[i]); + } + } + + cpumask_clear_cpu(cpu, &cpu_llc_shared_setup_map); +} + static inline void set_cpu_sibling_map(int cpu) { int i; @@ -401,6 +436,7 @@ int loongson_cpu_disable(void) #endif set_cpu_online(cpu, false); clear_cpu_sibling_map(cpu); + clear_cpu_llc_shared_map(cpu); calculate_cpu_foreign_map(); local_irq_save(flags); fixup_irqs(); @@ -522,6 +558,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) current_thread_info()->cpu = 0; loongson_prepare_cpus(max_cpus); set_cpu_sibling_map(0); + set_cpu_llc_shared_map(0); set_cpu_core_map(0); calculate_cpu_foreign_map(); #ifndef CONFIG_HOTPLUG_CPU @@ -563,6 +600,7 @@ asmlinkage void start_secondary(void) loongson_init_secondary(); set_cpu_sibling_map(cpu); + set_cpu_llc_shared_map(cpu); set_cpu_core_map(cpu); notify_cpu_starting(cpu); -- 2.33.0