[dpdk-stable] [PATCH 2/4] examples/vm_power: fix build with -fno-common

[Thomas Monjalon <thomas@monjalon.net>]

The variables of the same name are merged together
if compiled with -fcommon. It used to be the default.
This default behaviour allows to declare a variable in a header file and
share the variable in every .o binaries thanks to merge at link-time.

If compiling with -fno-common (default in GCC 10), the variable must be
shared as extern to avoid multiple re-definitions.

Fixes: dff22404aaad ("examples/vm_power_mgr: add VCPU to PCPU mapping")
Cc: stable@dpdk.org

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
 examples/vm_power_manager/channel_manager.c | 2 ++
 examples/vm_power_manager/channel_manager.h | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/examples/vm_power_manager/channel_manager.c b/examples/vm_power_manager/channel_manager.c
index 4ac21f02c1..4d13697208 100644
--- a/examples/vm_power_manager/channel_manager.c
+++ b/examples/vm_power_manager/channel_manager.c
@@ -35,6 +35,8 @@
 
 #define RTE_LOGTYPE_CHANNEL_MANAGER RTE_LOGTYPE_USER1
 
+struct libvirt_vm_info lvm_info[MAX_CLIENTS];
+
 /* Global pointer to libvirt connection */
 static virConnectPtr global_vir_conn_ptr;
 
diff --git a/examples/vm_power_manager/channel_manager.h b/examples/vm_power_manager/channel_manager.h
index 8284be0a18..a2a2f2bba0 100644
--- a/examples/vm_power_manager/channel_manager.h
+++ b/examples/vm_power_manager/channel_manager.h
@@ -41,7 +41,7 @@ struct libvirt_vm_info {
 	uint8_t num_cpus;
 };
 
-struct libvirt_vm_info lvm_info[MAX_CLIENTS];
+extern struct libvirt_vm_info lvm_info[MAX_CLIENTS];
 /* Communication Channel Status */
 enum channel_status { CHANNEL_MGR_CHANNEL_DISCONNECTED = 0,
 	CHANNEL_MGR_CHANNEL_CONNECTED,
-- 
2.26.2