CSIT-338 CpuUtils - CPU layout

Extends node from topology file with "cpuinfo", this information
can be defined in the topology file, or can be retrieved from the
node.

Change-Id: I913dba93daab3b41b36f3ab07f5c03ad46c659dd
Signed-off-by: Miroslav Miklus <mmiklus@cisco.com>

1 files changed, 100 insertions, 0 deletions

diff --git a/resources/libraries/python/CpuUtils.py b/resources/libraries/python/CpuUtils.py
new file mode 100644
index 0000000000..a8698dfd54
--- /dev/null
+++ b/resources/libraries/python/CpuUtils.py
@@ -0,0 +1,100 @@
+# Copyright (c) 2016 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""CPU utilities library"""
+
+from resources.libraries.python.ssh import SSH
+
+__all__ = ["CpuUtils"]
+
+class CpuUtils(object):
+    """CPU utilities"""
+
+    @staticmethod
+    def __str2int(string):
+        """Conversion from string to integer, 0 in case of empty string.
+
+        :param string: Input string.
+        :type string: str
+        :return: Integer converted from string, 0 in case of ValueError.
+        :rtype: int
+        """
+        try:
+            return int(string)
+        except ValueError:
+            return 0
+
+    @staticmethod
+    def get_cpu_layout_from_all_nodes(nodes):
+        """Retrieve cpu layout from all nodes, assuming all nodes
+           are Linux nodes.
+
+        :param nodes: DICT__nodes from Topology.DICT__nodes.
+        :type nodes: dict
+        """
+        ssh = SSH()
+        for node in nodes.values():
+            ssh.connect(node)
+            cmd = "lscpu -p"
+            ret, stdout, stderr = ssh.exec_command(cmd)
+#           parsing of "lscpu -p" output:
+#           # CPU,Core,Socket,Node,,L1d,L1i,L2,L3
+#           0,0,0,0,,0,0,0,0
+#           1,1,0,0,,1,1,1,0
+            if ret != 0:
+                raise RuntimeError(
+                    "Failed to execute ssh command, ret: {} err: {}".format(
+                        ret, stderr))
+            node['cpuinfo'] = list()
+            for line in stdout.split("\n"):
+                if len(line) > 0 and line[0] != "#":
+                    node['cpuinfo'].append([CpuUtils.__str2int(x) for x in
+                                            line.split(",")])
+
+    @staticmethod
+    def cpu_node_count(node):
+        """Return count of numa nodes.
+
+        :param node: Targeted node.
+        :type node: dict
+        :return: Count of numa nodes.
+        :rtype: int
+        """
+        cpuinfo = node.get("cpuinfo")
+        if cpuinfo is not None:
+            return node["cpuinfo"][-1][3] + 1
+        else:
+            raise RuntimeError("Node cpuinfo not available.")
+
+    @staticmethod
+    def cpu_list_per_node(node, cpu_node):
+        """Return node related list of CPU numbers.
+
+        :param node: Node dictionary with cpuinfo.
+        :param cpu_node: Numa node number.
+        :type node: int
+        :type cpu_node: int
+        :return: List of cpu numbers related to numa from argument.
+        :rtype: list of int
+        """
+        cpu_node = int(cpu_node)
+        cpuinfo = node.get("cpuinfo")
+        cpulist = []
+        if cpuinfo is not None:
+            for cpu in cpuinfo:
+                if cpu[3] == cpu_node:
+                    cpulist.append(cpu[0])
+        else:
+            raise RuntimeError("Node cpuinfo not available.")
+
+        return cpulist