doc: Add troublshooting section (#29)

* doc: Add troublshooting section

Signed-off-by: Brian McGinn <brian.mcginn@intel.com>
Co-authored-by: Jim Wang @ Intel <yutsung.jim.wang@intel.com>

docs_src/troubleshooting.md

@@ -0,0 +1,31 @@
+# Troubleshooting
+
+Q: Why is the performance on CPU sometimes better than on GPU, when running pipeline benchmarking like stream density?
+
+A: The performance of pipeline benchmarking strongly depends on the models.  Specifically for `yolov5s` object detection, it is recommended to use the model precision FP32 when it is running on device `GPU`.  If supported, then you can change the model precision by updating the pipeline script to point to the precision of your choice.  For example, you can change the model of `FP16` to `FP32` assuming the precision `FP32` of the target model is available:  
+
+```bash
+    src/pipelines/yolov5s.sh
+
+    ...
+    model=models/object_detection/yolov5s/FP16-INT8/yolov5s.xml
+    ...
+```
+
+Q: What happens if the system keeps crashing when building the `dlstreamer-realsense` image?
+
+A: Some systems may run into issues with memory when building the `dlstreamer-realsense` image. In the `Dockerfile.dlstreamer` file, change the make command to not use the `-j` threading option.
+
+```diff
+- make -j"$(cat < /proc/cpuinfo |grep -c proc)" &&
++ make &&
+```
+
+Q: What happens if the RTSP source is not found?
+
+A: Depending on your systems performance it is possible that the RTSP simulator may take additional time to initialize and start streaming. To avoid issues you can add a waiting period before the pipeline starts. For example you can add a 5 second sleep timer to /src/entrypoint.sh
+
+```bash
+sleep 5 # sleep for 5 seconds before starting the pipeline
+eval $gstLaunchCmd
+```

mkdocs.yml

@@ -57,6 +57,7 @@ nav:
           - Overview: 'use-cases/AiCSD/aicsd.md'
           - GRPC Yolov5s Pipeline: 'use-cases/AiCSD/pipeline-grpc-go.md'
   - Releases: 'releasenotes.md'
+  - Troubleshooting: 'troubleshooting.md'
 extra_css:
   - ./stylesheets/index.css
   - https://fonts.googleapis.com/icon?family=Material+Icons