CSIT-470 Add option to configure CFS scheduler priority for VPP

Add option to configure CFS scheduler priority for VPP

Change-Id: Id358ebe41d7e868fd412d554d886567f81894b86
Signed-off-by: pmikus <pmikus@cisco.com>

2 files changed, 120 insertions, 8 deletions

diff --git a/resources/libraries/python/SchedUtils.py b/resources/libraries/python/SchedUtils.py
new file mode 100644
index 0000000000..ec18b98dac
--- /dev/null
+++ b/resources/libraries/python/SchedUtils.py
@@ -0,0 +1,104 @@
+# 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))
diff --git a/resources/libraries/robot/default.robot b/resources/libraries/robot/default.robot
index dca7d53373..85cc4102cc 100644
--- a/resources/libraries/robot/default.robot
+++ b/resources/libraries/robot/default.robot
@@ -16,6 +16,7 @@
 | Library | resources.libraries.python.topology.Topology
 | Library | resources.libraries.python.CpuUtils
 | Library | resources.libraries.python.DUTSetup
+| Library | resources.libraries.python.SchedUtils
 | Library | resources.libraries.python.TGSetup
 | Library | resources/libraries/python/VppConfigGenerator.py
 | Library | resources/libraries/python/VppCounters.py
@@ -23,27 +24,27 @@
 
 *** Keywords ***
 | Setup all DUTs before test
-| | [Documentation] | Setup all DUTs in topology before test execution
+| | [Documentation] | Setup all DUTs in topology before test execution.
 | | Setup All DUTs | ${nodes}
 
 | Setup all TGs before traffic script
-| | [Documentation] | Prepare all TGs before traffic scripts execution
+| | [Documentation] | Prepare all TGs before traffic scripts execution.
 | | All TGs Set Interface Default Driver | ${nodes}
 
-| Show vpp version on all DUTs
-| | [Documentation] | Show VPP version verbose on all DUTs
+| Show Vpp Version On All DUTs
+| | [Documentation] | Show VPP version verbose on all DUTs.
 | | ${duts}= | Get Matches | ${nodes} | DUT*
 | | :FOR | ${dut} | IN | @{duts}
 | | | Vpp show version verbose | ${nodes['${dut}']}
 
-| Show Vpp Errors on All DUTs
-| | [Documentation] | Show VPP errors verbose on all DUTs
+| Show Vpp Errors On All DUTs
+| | [Documentation] | Show VPP errors verbose on all DUTs.
 | | ${duts}= | Get Matches | ${nodes} | DUT*
 | | :FOR | ${dut} | IN | @{duts}
 | | | Vpp Show Errors | ${nodes['${dut}']}
 
-| Show vpp trace dump on all DUTs
-| | [Documentation] | Save API trace and dump output on all DUTs
+| Show Vpp Trace Dump On All DUTs
+| | [Documentation] | Save API trace and dump output on all DUTs.
 | | ${duts}= | Get Matches | ${nodes} | DUT*
 | | :FOR | ${dut} | IN | @{duts}
 | | | Vpp api trace save | ${nodes['${dut}']}
@@ -55,6 +56,13 @@
 | | :FOR | ${dut} | IN | @{duts}
 | | | Vpp Show Vhost | ${nodes['${dut}']}
 
+| Setup Scheduler Policy for Vpp On All DUTs
+| | [Documentation] | Set realtime scheduling policy (SCHED_RR) with priority 1
+| | ...             | on all VPP worker threads on all DUTs.
+| | ${duts}= | Get Matches | ${nodes} | DUT*
+| | :FOR | ${dut} | IN | @{duts}
+| | | Set VPP Scheduling rr | ${nodes['${dut}']}
+
 | Add '${m}' worker threads and rxqueues '${n}' in 3-node single-link topo
 | | [Documentation] | Setup M worker threads and N rxqueues in vpp startup
 | | ...             | configuration on all DUTs in 3-node single-link topology.