sched: let arch_update_cpu_topology indicate if topology changed
Change arch_update_cpu_topology so it returns 1 if the cpu topology changed
and 0 if it didn't change. This will be useful for the next patch which adds
a call to this function in partition_sched_domains.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index a947899..bf96f1b 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -212,7 +212,7 @@
cpu_core_map[cpu] = cpu_coregroup_map(cpu);
}
-void arch_update_cpu_topology(void)
+int arch_update_cpu_topology(void)
{
struct tl_info *info = tl_info;
struct sys_device *sysdev;
@@ -221,7 +221,7 @@
if (!machine_has_topology) {
update_cpu_core_map();
topology_update_polarization_simple();
- return;
+ return 0;
}
stsi(info, 15, 1, 2);
tl_to_cores(info);
@@ -230,6 +230,7 @@
sysdev = get_cpu_sysdev(cpu);
kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
}
+ return 1;
}
static void topology_work_fn(struct work_struct *work)
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 117f1b7..0c5b5ac 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -49,7 +49,7 @@
for_each_online_node(node) \
if (nr_cpus_node(node))
-void arch_update_cpu_topology(void);
+int arch_update_cpu_topology(void);
/* Conform to ACPI 2.0 SLIT distance definitions */
#define LOCAL_DISTANCE 10
diff --git a/kernel/sched.c b/kernel/sched.c
index ef212da..fcfbbd9 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7675,8 +7675,14 @@
*/
static cpumask_t fallback_doms;
-void __attribute__((weak)) arch_update_cpu_topology(void)
+/*
+ * arch_update_cpu_topology lets virtualized architectures update the
+ * cpu core maps. It is supposed to return 1 if the topology changed
+ * or 0 if it stayed the same.
+ */
+int __attribute__((weak)) arch_update_cpu_topology(void)
{
+ return 0;
}
/*