[S390] cpu topology: introduce kernel parameter
Introduce a topology=[on|off] kernel parameter which allows to switch
cpu topology on/off. Default will be off, since it looks like that for
some workloards this doesn't behave very well (on s390).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 36faac5..71e6f56 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -58,6 +58,7 @@
cpumask_t mask;
};
+static int topology_enabled;
static void topology_work_fn(struct work_struct *work);
static struct tl_info *tl_info;
static struct core_info core_info;
@@ -78,7 +79,7 @@
cpumask_t mask;
cpus_clear(mask);
- if (!machine_has_topology)
+ if (!topology_enabled || !machine_has_topology)
return cpu_possible_map;
spin_lock_irqsave(&topology_lock, flags);
while (core) {
@@ -263,6 +264,15 @@
schedule_work(&topology_work);
}
+static int __init early_parse_topology(char *p)
+{
+ if (strncmp(p, "on", 2))
+ return 0;
+ topology_enabled = 1;
+ return 0;
+}
+early_param("topology", early_parse_topology);
+
static int __init init_topology_update(void)
{
int rc;