sched: add arch_update_cpu_topology hook.

Will be called each time the scheduling domains are rebuild.
Needed for architectures that don't have a static cpu topology.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/topology.h b/include/linux/topology.h
index 2d8dac8799cf..bd14f8b30f09 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -50,6 +50,8 @@
         for_each_online_node(node)                                              \
                 if (nr_cpus_node(node))
 
+void arch_update_cpu_topology(void);
+
 /* Conform to ACPI 2.0 SLIT distance definitions */
 #define LOCAL_DISTANCE          10
 #define REMOTE_DISTANCE         20
diff --git a/kernel/sched.c b/kernel/sched.c
index 78482e51b583..28c73f07efb2 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6807,6 +6807,10 @@ static int ndoms_cur;		/* number of sched domains in 'doms_cur' */
  */
 static cpumask_t fallback_doms;
 
+void __attribute__((weak)) arch_update_cpu_topology(void)
+{
+}
+
 /*
  * Set up scheduler domains and groups. Callers must hold the hotplug lock.
  * For now this just excludes isolated cpus, but could be used to
@@ -6816,6 +6820,7 @@ static int arch_init_sched_domains(const cpumask_t *cpu_map)
 {
         int err;
 
+        arch_update_cpu_topology();
         ndoms_cur = 1;
         doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
         if (!doms_cur)