Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[cascardo/linux.git] / arch / x86 / kernel / smpboot.c

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 0e91dbe..d0a5193 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -105,6 +105,9 @@ static unsigned int max_physical_pkg_id __read_mostly;
 unsigned int __max_logical_packages __read_mostly;
 EXPORT_SYMBOL(__max_logical_packages);
 
+/* Maximum number of SMT threads on any online core */
+int __max_smt_threads __read_mostly;
+
 static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
 {
        unsigned long flags;
@@ -493,7 +496,7 @@ void set_cpu_sibling_map(int cpu)
        bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1;
        struct cpuinfo_x86 *c = &cpu_data(cpu);
        struct cpuinfo_x86 *o;
-       int i;
+       int i, threads;
 
        cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
 
@@ -550,6 +553,10 @@ void set_cpu_sibling_map(int cpu)
                if (match_die(c, o) && !topology_same_node(c, o))
                        primarily_use_numa_for_topology();
        }
+
+       threads = cpumask_weight(topology_sibling_cpumask(cpu));
+       if (threads > __max_smt_threads)
+               __max_smt_threads = threads;
 }
 
 /* maps the cpu to the sched domain representing multi-core */
@@ -1440,6 +1447,21 @@ __init void prefill_possible_map(void)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
+/* Recompute SMT state for all CPUs on offline */
+static void recompute_smt_state(void)
+{
+       int max_threads, cpu;
+
+       max_threads = 0;
+       for_each_online_cpu (cpu) {
+               int threads = cpumask_weight(topology_sibling_cpumask(cpu));
+
+               if (threads > max_threads)
+                       max_threads = threads;
+       }
+       __max_smt_threads = max_threads;
+}
+
 static void remove_siblinginfo(int cpu)
 {
        int sibling;
@@ -1464,6 +1486,7 @@ static void remove_siblinginfo(int cpu)
        c->phys_proc_id = 0;
        c->cpu_core_id = 0;
        cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
+       recompute_smt_state();
 }
 
 static void remove_cpu_from_maps(int cpu)