[S390] topology: add SCHED_MC config option
This allows us to easily check for performance differences seen with
!CONFIG_SCHED_MC and topology=off.
Actually there shouldn't be any (besides a small overhead because of
additional code).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 97146ab..45a9bed 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -196,9 +196,18 @@
can be controlled through /sys/devices/system/cpu/cpu#.
Say N if you want to disable CPU hotplug.
+config SCHED_MC
+ def_bool y
+ prompt "Multi-core scheduler support"
+ depends on SMP
+ 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.
+
config SCHED_BOOK
bool "Book scheduler support"
- depends on SMP
+ depends on SMP && SCHED_MC
help
Book scheduler support improves the CPU scheduler's decision making
when dealing with machines that have several books.
diff --git a/arch/s390/kernel/sysinfo.c b/arch/s390/kernel/sysinfo.c
index f04d93a..5c9e439 100644
--- a/arch/s390/kernel/sysinfo.c
+++ b/arch/s390/kernel/sysinfo.c
@@ -106,11 +106,13 @@
for (i = 0; i < TOPOLOGY_NR_MAG; i++)
len += sprintf(page + len, " %d", info->mag[i]);
len += sprintf(page + len, "\n");
+#ifdef CONFIG_SCHED_MC
store_topology(info);
len += sprintf(page + len, "CPU Topology SW: ");
for (i = 0; i < TOPOLOGY_NR_MAG; i++)
len += sprintf(page + len, " %d", info->mag[i]);
len += sprintf(page + len, "\n");
+#endif
return len;
}