diff --git a/Makefile.am b/Makefile.am
index 9a31124..3a1b52b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -60,6 +60,7 @@
 	pid/zone.cpp \
 	pid/util.cpp \
 	pid/pidthread.cpp \
+	pid/tuning.cpp \
 	threads/busthread.cpp \
 	build/buildjson.cpp \
 	experiments/drive.cpp
diff --git a/README.md b/README.md
index e029d71..17465b2 100644
--- a/README.md
+++ b/README.md
@@ -254,14 +254,8 @@
 
 ### Enabling Logging
 
-By default, swampd isn't compiled to log information. To compile it for tuning,
-you'll need to add:
-
-```
-EXTRA_OEMAKE_append_YOUR_MACHINE = " CXXFLAGS='${CXXFLAGS} -D__TUNING_LOGGING__'"
-```
-
-To the recipe.
+By default, swampd won't log tuning information.  To enable this pass "-t" on
+the command line with a pareter of the path to write the log file.
 
 ## Project Information
 
diff --git a/main.cpp b/main.cpp
index d896300..cec3789 100644
--- a/main.cpp
+++ b/main.cpp
@@ -22,6 +22,7 @@
 #include "pid/builder.hpp"
 #include "pid/buildjson.hpp"
 #include "pid/pidthread.hpp"
+#include "pid/tuning.hpp"
 #include "pid/zone.hpp"
 #include "sensors/builder.hpp"
 #include "sensors/buildjson.hpp"
@@ -65,12 +66,13 @@
         // clang-format off
         static struct option long_options[] = {
             {"conf", required_argument, 0, 'c'},
+            {"tuning", required_argument, 0, 't'},
             {0, 0, 0, 0}
         };
         // clang-format on
 
         int option_index = 0;
-        int c = getopt_long(argc, argv, "c:", long_options, &option_index);
+        int c = getopt_long(argc, argv, "t:c:", long_options, &option_index);
 
         if (c == -1)
         {
@@ -82,6 +84,10 @@
             case 'c':
                 configPath = std::string{optarg};
                 break;
+            case 't':
+                tuningLoggingEnabled = true;
+                tuningLoggingPath = std::string{optarg};
+                break;
             default:
                 /* skip garbage. */
                 continue;
diff --git a/pid/fancontroller.cpp b/pid/fancontroller.cpp
index 4a61def..4c1b56b 100644
--- a/pid/fancontroller.cpp
+++ b/pid/fancontroller.cpp
@@ -16,6 +16,7 @@
 
 #include "fancontroller.hpp"
 
+#include "tuning.hpp"
 #include "util.hpp"
 #include "zone.hpp"
 
@@ -115,16 +116,17 @@
     double percent = value;
 
     /* If doing tuning logging, don't go into failsafe mode. */
-#ifndef __TUNING_LOGGING__
-    if (_owner->getFailSafeMode())
+    if (!tuningLoggingEnabled)
     {
-        /* In case it's being set to 100% */
-        if (percent < _owner->getFailSafePercent())
+        if (_owner->getFailSafeMode())
         {
-            percent = _owner->getFailSafePercent();
+            /* In case it's being set to 100% */
+            if (percent < _owner->getFailSafePercent())
+            {
+                percent = _owner->getFailSafePercent();
+            }
         }
     }
-#endif
 
     // value and kFanFailSafeDutyCycle are 10 for 10% so let's fix that.
     percent /= 100;
diff --git a/pid/pidthread.cpp b/pid/pidthread.cpp
index 08fb513..f8d7fd9 100644
--- a/pid/pidthread.cpp
+++ b/pid/pidthread.cpp
@@ -17,6 +17,7 @@
 #include "pidthread.hpp"
 
 #include "pid/pidcontroller.hpp"
+#include "pid/tuning.hpp"
 #include "sensors/sensor.hpp"
 
 #include <chrono>
@@ -63,9 +64,11 @@
      * TODO(venture): If the fan value is 0 should that loop just be skipped?
      * Right now, a 0 value is ignored in FanController::inputProc()
      */
-#ifdef __TUNING_LOGGING__
-    zone->initializeLog();
-#endif
+    if (tuningLoggingEnabled)
+    {
+        zone->initializeLog();
+    }
+
     zone->initializeCache();
     processThermals(zone);
 
@@ -93,10 +96,11 @@
         // Run the fan PIDs every iteration.
         zone->processFans();
 
-#ifdef __TUNING_LOGGING__
-        zone->getLogHandle() << "," << zone->getFailSafeMode();
-        zone->getLogHandle() << std::endl;
-#endif
+        if (tuningLoggingEnabled)
+        {
+            zone->getLogHandle() << "," << zone->getFailSafeMode();
+            zone->getLogHandle() << std::endl;
+        }
 
         ms100cnt += 1;
     }
diff --git a/pid/tuning.cpp b/pid/tuning.cpp
new file mode 100644
index 0000000..c3f21ed
--- /dev/null
+++ b/pid/tuning.cpp
@@ -0,0 +1,20 @@
+/**
+ * Copyright 2019 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 <string>
+
+bool tuningLoggingEnabled = false;
+std::string tuningLoggingPath;
diff --git a/pid/tuning.hpp b/pid/tuning.hpp
new file mode 100644
index 0000000..511c797
--- /dev/null
+++ b/pid/tuning.hpp
@@ -0,0 +1,9 @@
+#pragma once
+
+#include <string>
+
+/** Boolean variable controlling whether tuning logging output is enabled
+ * during this run.
+ */
+extern bool tuningLoggingEnabled;
+extern std::string tuningLoggingPath;
diff --git a/pid/zone.cpp b/pid/zone.cpp
index 7433d30..928aef5 100644
--- a/pid/zone.cpp
+++ b/pid/zone.cpp
@@ -23,6 +23,7 @@
 #include "pid/fancontroller.hpp"
 #include "pid/stepwisecontroller.hpp"
 #include "pid/thermalcontroller.hpp"
+#include "pid/tuning.hpp"
 
 #include <algorithm>
 #include <chrono>
@@ -138,38 +139,38 @@
      */
     max = std::max(getMinThermalRPMSetpoint(), max);
 
-#ifdef __TUNING_LOGGING__
-    /*
-     * We received no setpoints from thermal sensors.
-     * This is a case experienced during tuning where they only specify
-     * fan sensors and one large fan PID for all the fans.
-     */
-    static constexpr auto setpointpath = "/etc/thermal.d/setpoint";
-    try
+    if (tuningLoggingEnabled)
     {
-        std::ifstream ifs;
-        ifs.open(setpointpath);
-        if (ifs.good())
+        /*
+         * We received no setpoints from thermal sensors.
+         * This is a case experienced during tuning where they only specify
+         * fan sensors and one large fan PID for all the fans.
+         */
+        static constexpr auto setpointpath = "/etc/thermal.d/setpoint";
+        try
         {
-            int value;
-            ifs >> value;
+            std::ifstream ifs;
+            ifs.open(setpointpath);
+            if (ifs.good())
+            {
+                int value;
+                ifs >> value;
 
-            /* expecting RPM setpoint, not pwm% */
-            max = static_cast<double>(value);
+                /* expecting RPM setpoint, not pwm% */
+                max = static_cast<double>(value);
+            }
+        }
+        catch (const std::exception& e)
+        {
+            /* This exception is uninteresting. */
+            std::cerr << "Unable to read from '" << setpointpath << "'\n";
         }
     }
-    catch (const std::exception& e)
-    {
-        /* This exception is uninteresting. */
-        std::cerr << "Unable to read from '" << setpointpath << "'\n";
-    }
-#endif
 
     _maximumRPMSetPt = max;
     return;
 }
 
-#ifdef __TUNING_LOGGING__
 void PIDZone::initializeLog(void)
 {
     /* Print header for log file:
@@ -196,7 +197,6 @@
 {
     return _log;
 }
-#endif
 
 /*
  * TODO(venture) This is effectively updating the cache and should check if the
@@ -217,13 +217,14 @@
      * is disabled?  I think it's a waste to try and log things even if the
      * data is just being dropped though.
      */
-#ifdef __TUNING_LOGGING__
-    tstamp now = std::chrono::high_resolution_clock::now();
-    _log << std::chrono::duration_cast<std::chrono::milliseconds>(
-                now.time_since_epoch())
-                .count();
-    _log << "," << _maximumRPMSetPt;
-#endif
+    if (tuningLoggingEnabled)
+    {
+        tstamp now = std::chrono::high_resolution_clock::now();
+        _log << std::chrono::duration_cast<std::chrono::milliseconds>(
+                    now.time_since_epoch())
+                    .count();
+        _log << "," << _maximumRPMSetPt;
+    }
 
     for (const auto& f : _fanInputs)
     {
@@ -236,17 +237,19 @@
          * However, these are the fans, so if I'm not getting updated values
          * for them... what should I do?
          */
-#ifdef __TUNING_LOGGING__
-        _log << "," << r.value;
-#endif
+        if (tuningLoggingEnabled)
+        {
+            _log << "," << r.value;
+        }
     }
 
-#ifdef __TUNING_LOGGING__
-    for (const auto& t : _thermalInputs)
+    if (tuningLoggingEnabled)
     {
-        _log << "," << _cachedValuesByName[t];
+        for (const auto& t : _thermalInputs)
+        {
+            _log << "," << _cachedValuesByName[t];
+        }
     }
-#endif
 
     return;
 }
diff --git a/pid/zone.hpp b/pid/zone.hpp
index 94082e9..a458011 100644
--- a/pid/zone.hpp
+++ b/pid/zone.hpp
@@ -5,6 +5,7 @@
 #include "pidcontroller.hpp"
 #include "sensors/manager.hpp"
 #include "sensors/sensor.hpp"
+#include "tuning.hpp"
 
 #include <fstream>
 #include <map>
@@ -51,9 +52,10 @@
         _minThermalOutputSetPt(minThermalOutput),
         _failSafePercent(failSafePercent), _mgr(mgr)
     {
-#ifdef __TUNING_LOGGING__
-        _log.open("/tmp/swampd.log");
-#endif
+        if (tuningLoggingEnabled && !tuningLoggingPath.empty())
+        {
+            _log.open(tuningLoggingPath);
+        }
     }
 
     double getMaxRPMRequest(void) const override;
@@ -87,10 +89,8 @@
     void addFanInput(const std::string& fan);
     void addThermalInput(const std::string& therm);
 
-#ifdef __TUNING_LOGGING__
     void initializeLog(void);
     std::ofstream& getLogHandle(void);
-#endif
 
     /* Method for setting the manual mode over dbus */
     bool manual(bool value) override;
@@ -98,9 +98,7 @@
     bool failSafe() const override;
 
   private:
-#ifdef __TUNING_LOGGING__
     std::ofstream _log;
-#endif
 
     const int64_t _zoneId;
     double _maximumRPMSetPt = 0;
diff --git a/test/Makefile.am b/test/Makefile.am
index 04cf2df..07c96ce 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -37,7 +37,7 @@
 pid_zone_unittest_SOURCES = pid_zone_unittest.cpp
 pid_zone_unittest_LDADD = $(top_builddir)/pid/ec/pid.o \
  $(top_builddir)/sensors/manager.o $(top_builddir)/pid/pidcontroller.o \
- $(top_builddir)/pid/zone.o
+ $(top_builddir)/pid/zone.o $(top_builddir)/pid/tuning.o
 
 pid_thermalcontroller_unittest_SOURCES = pid_thermalcontroller_unittest.cpp
 pid_thermalcontroller_unittest_LDADD = $(top_builddir)/pid/ec/pid.o \
@@ -51,7 +51,7 @@
 pid_fancontroller_unittest_SOURCES = pid_fancontroller_unittest.cpp
 pid_fancontroller_unittest_LDADD = $(top_builddir)/pid/ec/pid.o \
  $(top_builddir)/pid/util.o $(top_builddir)/pid/pidcontroller.o \
- $(top_builddir)/pid/fancontroller.o
+ $(top_builddir)/pid/fancontroller.o $(top_builddir)/pid/tuning.o
 
 dbus_passive_unittest_SOURCES = dbus_passive_unittest.cpp
 dbus_passive_unittest_LDADD = $(top_builddir)/dbus/util.o \