cpupower: Better detect offlined CPUs

Before, checking for offlined CPUs was done dirty and
it was checked whether topology parsing returned -1 values.
But this is a valid case on a Xen (and possibly other) kernels.

Do proper online/offline checking, also take CONFIG_HOTPLUG_CPU
option into account (no /sys/devices/../cpuX/online file).

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/tools/power/cpupower/utils/helpers/sysfs.h b/tools/power/cpupower/utils/helpers/sysfs.h
index f9373e090637..8cb797bbceb0 100644
--- a/tools/power/cpupower/utils/helpers/sysfs.h
+++ b/tools/power/cpupower/utils/helpers/sysfs.h
@@ -7,6 +7,8 @@
 
 extern unsigned int sysfs_read_file(const char *path, char *buf, size_t buflen);
 
+extern int sysfs_is_cpu_online(unsigned int cpu);
+
 extern unsigned long sysfs_get_idlestate_latency(unsigned int cpu,
                                                 unsigned int idlestate);
 extern unsigned long sysfs_get_idlestate_usage(unsigned int cpu,