arch/x86_64/kernel/domain.c

   1 #include <linux/init.h>
   2 #include <linux/sched.h>
   3
   4 /* Don't do any NUMA setup on Opteron right now. They seem to be
   5    better off with flat scheduling. This is just for SMT. */
   6
   7 #ifdef CONFIG_SCHED_SMT
   8
   9 static struct sched_group sched_group_cpus[NR_CPUS];
  10 static struct sched_group sched_group_phys[NR_CPUS];
  11 static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
  12 static DEFINE_PER_CPU(struct sched_domain, phys_domains);
  13 __init void arch_init_sched_domains(void)
  14 {
  15         int i;
  16         struct sched_group *first = NULL, *last = NULL;
  17
  18         /* Set up domains */
  19         for_each_cpu(i) {
  20                 struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
  21                 struct sched_domain *phys_domain = &per_cpu(phys_domains, i);
  22
  23                 *cpu_domain = SD_SIBLING_INIT;
  24                 /* Disable SMT NICE for CMP */
  25                 /* RED-PEN use a generic flag */
  26                 if (cpu_data[i].x86_vendor == X86_VENDOR_AMD)
  27                         cpu_domain->flags &= ~SD_SHARE_CPUPOWER;
  28                 cpu_domain->span = cpu_sibling_map[i];
  29                 cpu_domain->parent = phys_domain;
  30                 cpu_domain->groups = &sched_group_cpus[i];
  31
  32                 *phys_domain = SD_CPU_INIT;
  33                 phys_domain->span = cpu_possible_map;
  34                 phys_domain->groups = &sched_group_phys[first_cpu(cpu_domain->span)];
  35         }
  36
  37         /* Set up CPU (sibling) groups */
  38         for_each_cpu(i) {
  39                 struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
  40                 int j;
  41                 first = last = NULL;
  42
  43                 if (i != first_cpu(cpu_domain->span))
  44                         continue;
  45
  46                 for_each_cpu_mask(j, cpu_domain->span) {
  47                         struct sched_group *cpu = &sched_group_cpus[j];
  48
  49                         cpus_clear(cpu->cpumask);
  50                         cpu_set(j, cpu->cpumask);
  51                         cpu->cpu_power = SCHED_LOAD_SCALE;
  52
  53                         if (!first)
  54                                 first = cpu;
  55                         if (last)
  56                                 last->next = cpu;
  57                         last = cpu;
  58                 }
  59                 last->next = first;
  60         }
  61
  62         first = last = NULL;
  63         /* Set up physical groups */
  64         for_each_cpu(i) {
  65                 struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
  66                 struct sched_group *cpu = &sched_group_phys[i];
  67
  68                 if (i != first_cpu(cpu_domain->span))
  69                         continue;
  70
  71                 cpu->cpumask = cpu_domain->span;
  72                 /*
  73                  * Make each extra sibling increase power by 10% of
  74                  * the basic CPU. This is very arbitrary.
  75                  */
  76                 cpu->cpu_power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE*(cpus_weight(cpu->cpumask)-1) / 10;
  77
  78                 if (!first)
  79                         first = cpu;
  80                 if (last)
  81                         last->next = cpu;
  82                 last = cpu;
  83         }
  84         last->next = first;
  85
  86         mb();
  87         for_each_cpu(i) {
  88                 struct sched_domain *cpu_domain = &per_cpu(cpu_domains, i);
  89                 cpu_attach_domain(cpu_domain, i);
  90         }
  91 }
  92
  93 #endif