From 2a636a56d2d39676fe85190dec102c7440e24977 Mon Sep 17 00:00:00 2001 From: Oliver O'Halloran Date: Thu, 29 Jun 2017 17:12:55 +1000 Subject: [PATCH] powerpc/smp: Add cpu_l2_cache_map We want to add an extra level to the CPU scheduler topology to account for cores which share a cache. To do this we need to build a cpumask for each CPU that indicates which CPUs share this cache to use as an input to the scheduler. Signed-off-by: Oliver O'Halloran Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/smp.h | 6 ++++++ arch/powerpc/kernel/smp.c | 23 +++++++++++++++++------ 2 files changed, 23 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 8ea9850..fac963e 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -97,6 +97,7 @@ static inline void set_hard_smp_processor_id(int cpu, int phys) #endif DECLARE_PER_CPU(cpumask_var_t, cpu_sibling_map); +DECLARE_PER_CPU(cpumask_var_t, cpu_l2_cache_map); DECLARE_PER_CPU(cpumask_var_t, cpu_core_map); static inline struct cpumask *cpu_sibling_mask(int cpu) @@ -109,6 +110,11 @@ static inline struct cpumask *cpu_core_mask(int cpu) return per_cpu(cpu_core_map, cpu); } +static inline struct cpumask *cpu_l2_cache_mask(int cpu) +{ + return per_cpu(cpu_l2_cache_map, cpu); +} + extern int cpu_to_core_id(int cpu); /* Since OpenPIC has only 4 IPIs, we use slightly different message numbers. diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index a29c23b..b42c868 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -75,9 +75,11 @@ static DEFINE_PER_CPU(int, cpu_state) = { 0 }; struct thread_info *secondary_ti; DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map); +DEFINE_PER_CPU(cpumask_var_t, cpu_l2_cache_map); DEFINE_PER_CPU(cpumask_var_t, cpu_core_map); EXPORT_PER_CPU_SYMBOL(cpu_sibling_map); +EXPORT_PER_CPU_SYMBOL(cpu_l2_cache_map); EXPORT_PER_CPU_SYMBOL(cpu_core_map); /* SMP operations for this machine */ @@ -610,6 +612,8 @@ void __init smp_prepare_cpus(unsigned int max_cpus) for_each_possible_cpu(cpu) { zalloc_cpumask_var_node(&per_cpu(cpu_sibling_map, cpu), GFP_KERNEL, cpu_to_node(cpu)); + zalloc_cpumask_var_node(&per_cpu(cpu_l2_cache_map, cpu), + GFP_KERNEL, cpu_to_node(cpu)); zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu), GFP_KERNEL, cpu_to_node(cpu)); /* @@ -624,6 +628,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) /* Init the cpumasks so the boot CPU is related to itself */ cpumask_set_cpu(boot_cpuid, cpu_sibling_mask(boot_cpuid)); + cpumask_set_cpu(boot_cpuid, cpu_l2_cache_mask(boot_cpuid)); cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid)); if (smp_ops && smp_ops->probe) @@ -907,6 +912,7 @@ static void remove_cpu_from_masks(int cpu) /* NB: cpu_core_mask is a superset of the others */ for_each_cpu(i, cpu_core_mask(cpu)) { set_cpus_unrelated(cpu, i, cpu_core_mask); + set_cpus_unrelated(cpu, i, cpu_l2_cache_mask); set_cpus_unrelated(cpu, i, cpu_sibling_mask); } } @@ -929,17 +935,22 @@ static void add_cpu_to_masks(int cpu) set_cpus_related(i, cpu, cpu_sibling_mask); /* - * Copy the thread sibling into core sibling mask, and - * add CPUs that share a chip or an L2 to the core sibling - * mask. + * Copy the thread sibling mask into the cache sibling mask + * and mark any CPUs that share an L2 with this CPU. */ for_each_cpu(i, cpu_sibling_mask(cpu)) + set_cpus_related(cpu, i, cpu_l2_cache_mask); + update_mask_by_l2(cpu, cpu_l2_cache_mask); + + /* + * Copy the cache sibling mask into core sibling mask and mark + * any CPUs on the same chip as this CPU. + */ + for_each_cpu(i, cpu_l2_cache_mask(cpu)) set_cpus_related(cpu, i, cpu_core_mask); - if (chipid == -1) { - update_mask_by_l2(cpu, cpu_core_mask); + if (chipid == -1) return; - } for_each_cpu(i, cpu_online_mask) if (cpu_to_chip_id(i) == chipid) -- 2.7.4