docs: Use switchconfig with extra condition

devito/logger.py

@@ -13,13 +13,13 @@
 stream_handler = logging.StreamHandler()
 logger.addHandler(stream_handler)
 
-# Add extra logging levels (note: INFO has value=20, WARNING has value=30)
-DEBUG = logging.DEBUG
+# Add extra logging levels
+DEBUG = logging.DEBUG  # value=10
 PERF = 19
-INFO = logging.INFO
-WARNING = logging.WARNING
-ERROR = logging.ERROR
-CRITICAL = logging.CRITICAL
+INFO = logging.INFO  # value=20
+WARNING = logging.WARNING  # value=30
+ERROR = logging.ERROR  # value=40
+CRITICAL = logging.CRITICAL  # value=50
 
 logging.addLevelName(PERF, "PERF")
 
@@ -71,13 +71,13 @@ def set_log_level(level, comm=None):
     comm : MPI communicator, optional
         An MPI communicator the logger should be collective over. If provided, only
         rank-0 on that communicator will write to the registered handlers, other
-        ranks will use a `logging.NullHandler`.  By default, ``comm`` is set
-        to ``None``, so all ranks will use the default handlers.  This could be
+        ranks will use a `logging.NullHandler`. By default, ``comm`` is set
+        to ``None``, so all ranks will use the default handlers. This could be
         used, for example, if one wants to log to one file per rank.
     """
     from devito import configuration
 
-    if comm is not None and configuration['mpi']:
+    if comm is not None:
         if comm.rank != 0:
             logger.removeHandler(stream_handler)
             logger.addHandler(logging.NullHandler())

devito/operator/operator.py

@@ -872,10 +872,14 @@ def apply(self, **kwargs):
         # Post-process runtime arguments
         self._postprocess_arguments(args, **kwargs)
 
-        # Output summary of performance achieved and
-        # temporarily drop MPI for printing arguments
-        with switchconfig(mpi=False):
-            return self._emit_apply_profiling(args)
+        # In case MPI is used restrict result logging to one rank only
+        if configuration['mpi']:
+            # Only temporarily change configuration
+            with switchconfig(mpi=True):
+                set_log_level('DEBUG', comm=args.comm)
+                return self._emit_apply_profiling(args)
+
+        return self._emit_apply_profiling(args)
 
     # Performance profiling
 
@@ -913,9 +917,6 @@ def _emit_timings(timings, indent=''):
     def _emit_apply_profiling(self, args):
         """Produce a performance summary of the profiled sections."""
 
-        # In case MPI is used restrict result logging to one rank
-        set_log_level('DEBUG', comm=args.comm)
-
         # Rounder to 2 decimal places
         fround = lambda i: ceil(i * 100) / 100