Remove threads
This converts phosphor-pid-control into an async
single threaded application. The reason for doing this
is on our systems phosphor-pid-control had the largest
VSZ when viewed under top. Before this patch the VSZ
was at 50720, after it is at 7760.
Tested-by: Could still interact with all interfaces
under rest-dbus and sensor override worked to ramp fans
when changing cpu temps.
Change-Id: Ie0a837bdf0d1b1df61dc7aff87e5d503b9e0e875
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/pid/pidloop.cpp b/pid/pidloop.cpp
new file mode 100644
index 0000000..b684747
--- /dev/null
+++ b/pid/pidloop.cpp
@@ -0,0 +1,117 @@
+/**
+ * Copyright 2017 Google Inc.
+ *
+ * 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.
+ */
+
+#include "pidloop.hpp"
+
+#include "pid/pidcontroller.hpp"
+#include "pid/tuning.hpp"
+#include "sensors/sensor.hpp"
+
+#include <boost/asio/steady_timer.hpp>
+#include <chrono>
+#include <map>
+#include <memory>
+#include <thread>
+#include <vector>
+
+static void processThermals(PIDZone* zone)
+{
+ // Get the latest margins.
+ zone->updateSensors();
+ // Zero out the RPM set point goals.
+ zone->clearRPMSetPoints();
+ zone->clearRPMCeilings();
+ // Run the margin PIDs.
+ zone->processThermals();
+ // Get the maximum RPM setpoint.
+ zone->determineMaxRPMRequest();
+}
+
+void pidControlLoop(PIDZone* zone, boost::asio::steady_timer& timer, bool first,
+ int ms100cnt)
+{
+ if (first)
+ {
+ if (tuningLoggingEnabled)
+ {
+ zone->initializeLog();
+ }
+
+ zone->initializeCache();
+ processThermals(zone);
+ }
+
+ timer.expires_after(std::chrono::milliseconds(100));
+ timer.async_wait(
+ [zone, &timer, ms100cnt](const boost::system::error_code& ec) mutable {
+ /*
+ * This should sleep on the conditional wait for the listen thread
+ * to tell us it's in sync. But then we also need a timeout option
+ * in case phosphor-hwmon is down, we can go into some weird failure
+ * more.
+ *
+ * Another approach would be to start all sensors in worst-case
+ * values, and fail-safe mode and then clear out of fail-safe mode
+ * once we start getting values. Which I think it is a solid
+ * approach.
+ *
+ * For now this runs before it necessarily has any sensor values.
+ * For the host sensors they start out in fail-safe mode. For the
+ * fans, they start out as 0 as input and then are adjusted once
+ * they have values.
+ *
+ * If a fan has failed, it's value will be whatever we're told or
+ * however we retrieve it. This program disregards fan values of 0,
+ * so any code providing a fan speed can set to 0 on failure and
+ * that fan value will be effectively ignored. The PID algorithm
+ * will be unhappy but nothing bad will happen.
+ *
+ * TODO(venture): If the fan value is 0 should that loop just be
+ * skipped? Right now, a 0 value is ignored in
+ * FanController::inputProc()
+ */
+
+ // Check if we should just go back to sleep.
+ if (zone->getManualMode())
+ {
+ pidControlLoop(zone, timer, false, ms100cnt);
+ return;
+ }
+
+ // Get the latest fan speeds.
+ zone->updateFanTelemetry();
+
+ if (10 <= ms100cnt)
+ {
+ ms100cnt = 0;
+
+ processThermals(zone);
+ }
+
+ // Run the fan PIDs every iteration.
+ zone->processFans();
+
+ if (tuningLoggingEnabled)
+ {
+ zone->getLogHandle() << "," << zone->getFailSafeMode();
+ zone->getLogHandle() << std::endl;
+ }
+
+ ms100cnt += 1;
+
+ pidControlLoop(zone, timer, false, ms100cnt);
+ });
+}