3 files changed, 35 insertions, 1 deletions

diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 45efe0ca88f8..1cb4aa241c8c 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -250,6 +250,15 @@ config SCHED_SMT
           cost of slightly increased overhead in some places. If unsure say
           N here.
 
+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. If unsure say N here.
+
 source "kernel/Kconfig.preempt"
 
 config NUMA
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
index a57eec8311a7..d1f3e9272c05 100644
--- a/arch/x86_64/kernel/setup.c
+++ b/arch/x86_64/kernel/setup.c
@@ -962,7 +962,6 @@ static void __cpuinit detect_ht(struct cpuinfo_x86 *c)
 
         cpuid(1, &eax, &ebx, &ecx, &edx);
 
-        c->apicid = phys_pkg_id(0);
 
         if (!cpu_has(c, X86_FEATURE_HT) || cpu_has(c, X86_FEATURE_CMP_LEGACY))
                 return;
@@ -1171,6 +1170,8 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
                         c->x86_capability[2] = cpuid_edx(0x80860001);
         }
 
+        c->apicid = phys_pkg_id(0);
+
         /*
          * Vendor-specific initialization.  In this section we
          * canonicalize the feature flags, meaning if there are
diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 66e98659d077..ea48fa638070 100644
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -68,6 +68,9 @@ u8 phys_proc_id[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
 /* core ID of each logical CPU */
 u8 cpu_core_id[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
 
+/* Last level cache ID of each logical CPU */
+u8 cpu_llc_id[NR_CPUS] __cpuinitdata  = {[0 ... NR_CPUS-1] = BAD_APICID};
+
 /* Bitmask of currently online CPUs */
 cpumask_t cpu_online_map __read_mostly;
 
@@ -445,6 +448,18 @@ void __cpuinit smp_callin(void)
         cpu_set(cpuid, cpu_callin_map);
 }
 
+/* maps the cpu to the sched domain representing multi-core */
+cpumask_t cpu_coregroup_map(int cpu)
+{
+        struct cpuinfo_x86 *c = cpu_data + cpu;
+        /*
+         * For perf, we return last level cache shared map.
+         * TBD: when power saving sched policy is added, we will return
+         *      cpu_core_map when power saving policy is enabled
+         */
+        return c->llc_shared_map;
+}
+
 /* representing cpus for which sibling maps can be computed */
 static cpumask_t cpu_sibling_setup_map;
 
@@ -463,12 +478,16 @@ static inline void set_cpu_sibling_map(int cpu)
                                 cpu_set(cpu, cpu_sibling_map[i]);
                                 cpu_set(i, cpu_core_map[cpu]);
                                 cpu_set(cpu, cpu_core_map[i]);
+                                cpu_set(i, c[cpu].llc_shared_map);
+                                cpu_set(cpu, c[i].llc_shared_map);
                         }
                 }
         } else {
                 cpu_set(cpu, cpu_sibling_map[cpu]);
         }
 
+        cpu_set(cpu, c[cpu].llc_shared_map);
+
         if (current_cpu_data.x86_max_cores == 1) {
                 cpu_core_map[cpu] = cpu_sibling_map[cpu];
                 c[cpu].booted_cores = 1;
@@ -476,6 +495,11 @@ static inline void set_cpu_sibling_map(int cpu)
         }
 
         for_each_cpu_mask(i, cpu_sibling_setup_map) {
+                if (cpu_llc_id[cpu] != BAD_APICID &&
+                    cpu_llc_id[cpu] == cpu_llc_id[i]) {
+                        cpu_set(i, c[cpu].llc_shared_map);
+                        cpu_set(cpu, c[i].llc_shared_map);
+                }
                 if (phys_proc_id[cpu] == phys_proc_id[i]) {
                         cpu_set(i, cpu_core_map[cpu]);
                         cpu_set(cpu, cpu_core_map[i]);