+# 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.
+
+"""Linux scheduler util library"""
+from resources.libraries.python.ssh import SSH
+
+
+__all__ = ["SchedUtils"]
+
+class SchedUtils(object):
+ """General class for any linux scheduler related methods/functions."""
+
+ @staticmethod
+ def set_vpp_scheduling_rr(node):
+ """Set real-time scheduling attributes of VPP worker threads to
+ SCHED_RR with priority 1.
+
+ :param node: DUT node with running VPP.
+ :type node: dict
+ :raises RuntimeError: Failed to retrieve PID for VPP worker threads.
+ """
+ ssh = SSH()
+ ssh.connect(node)
+
+ cmd = "cat /proc/`pidof vpp`/task/*/stat | grep -i vpp_wk"\
+ " | awk '{print $1}'"
+
+ for _ in range(3):
+ (ret, out, _) = ssh.exec_command_sudo(cmd)
+ if ret == 0:
+ try:
+ if not out:
+ raise ValueError
+ except ValueError:
+ print 'Reading VPP worker thread PID failed.'
+ else:
+ for pid in out.split("\n"):
+ if len(pid) > 0 and pid[0] != "#":
+ SchedUtils.set_proc_scheduling_rr(node, int(pid))
+ break
+ else:
+ raise RuntimeError('Failed to retrieve PID for VPP worker threads.')
+
+ @staticmethod
+ def set_proc_scheduling_rr(node, pid, priority=1):
+ """Set real-time scheduling of a process to SCHED_RR with priority for
+ specified PID.
+
+ :param node: Node where to apply scheduling changes.
+ :param pid: Process ID.
+ :param priority: Realtime priority in range 1-99. Default is 1.
+ :type node: dict
+ :type pid: int
+ :type priority: int
+ :raises ValueError: Parameters out of allowed ranges.
+ :raises RuntimeError: Failed to set policy for PID.
+ """
+ ssh = SSH()
+ ssh.connect(node)
+
+ if pid < 1:
+ raise ValueError("SCHED_RR: PID must be higher then 1.")
+
+ if 1 <= priority <= 99:
+ cmd = "chrt -r -p {0} {1}".format(priority, pid)
+ (ret, _, _) = ssh.exec_command_sudo(cmd)
+ if ret != 0:
+ raise RuntimeError("SCHED_RR: Failed to set policy "\
+ "for PID {0}.".format(pid))
+ else:
+ raise ValueError("SCHED_RR: Priority must be in range 1-99.")
+
+ @staticmethod
+ def set_proc_scheduling_other(node, pid):
+ """Set normal scheduling of a process to SCHED_OTHER for specified PID.
+
+ :param node: Node where to apply scheduling changes.
+ :param pid: Process ID.
+ :type node: dict
+ :type pid: int
+ :raises ValueError: Parameters out of allowed ranges.
+ :raises RuntimeError: Failed to set policy for PID.
+ """
+ ssh = SSH()
+ ssh.connect(node)
+
+ if pid < 1:
+ raise ValueError("SCHED_OTHER: PID must be higher then 1.")
+
+ cmd = "chrt -o -p 0 {1}".format(pid)
+ (ret, _, _) = ssh.exec_command_sudo(cmd)
+ if ret != 0:
+ raise RuntimeError("SCHED_OTHER: Failed to set policy "\
+ "for PID {0}.".format(pid))
Code Review / csit.git / commitdiff