ceph/doc/dev/developer_guide/debugging-gdb.rst

   1 GDB - The GNU Project Debugger
   2 ==============================
   3
   4 `The GNU Project Debugger (GDB) <https://www.sourceware.org/gdb>`_ is
   5 a powerful tool that allows you to analyze the execution flow
   6 of a process.
   7 GDB can help to find bugs, uncover crash errors or track the
   8 source code during execution of a development cluster.
   9 It can also be used to debug Teuthology test runs.
  10
  11 GET STARTED WITH GDB
  12 --------------------
  13
  14 Basic usage with examples can be found `here. <https://geeksforgeeks.org/gdb-command-in-linux-with-examples>`_
  15 GDB can be attached to a running process. For instance, after deploying a
  16 development cluster, the process number (PID) of a ``ceph-osd`` daemon can be found in::
  17
  18     $ cd build
  19     $ cat out/osd.0.pid
  20
  21 Attaching gdb to the process::
  22
  23     $ gdb ./bin/ceph-osd -p <pid>
  24
  25 .. note::
  26     It is recommended to compile without any optimizations (``-O0`` gcc flag)
  27     in order to avoid elimination of intermediate values.
  28
  29 Stopping for breakpoints while debugging may cause timeouts, so the following
  30 configuration options are suggested::
  31
  32         [osd]
  33         osd_op_thread_timeout = 1500
  34         osd_op_thread_suicide_timeout = 1500
  35
  36 Debugging Teuthology Tests
  37 ^^^^^^^^^^^^^^^^^^^^^^^^^^
  38
  39 ``src/script/ceph-debug-docker.sh`` can be used to analyze Teuthology failures::
  40
  41     $ ./ceph-debug-docker.sh <branch-name>
  42
  43 Refer to the script header for more information.