diff --git a/src/allmydata/frontends/magic_folder.py b/src/allmydata/frontends/magic_folder.py
index 474dc5fe2..f1e145d0e 100644
--- a/src/allmydata/frontends/magic_folder.py
+++ b/src/allmydata/frontends/magic_folder.py
@@ -460,6 +460,19 @@ PERFORM_SCAN = ActionType(
     u"Remote storage is being scanned for changes which need to be synchronized.",
 )
 
+_COUNT = Field.for_types(
+    u"count",
+    [int, long],
+    u"The number of items in the processing queue.",
+)
+
+PROCESS_QUEUE = ActionType(
+    u"magic-folder:process-queue",
+    [_COUNT],
+    [],
+    u"A Magic-Folder is working through an item queue.",
+)
+
 SCAN_REMOTE_COLLECTIVE = ActionType(
     u"magic-folder:scan-remote-collective",
     [],
@@ -713,7 +726,7 @@ class QueueMixin(HookMixin):
     def _perform_scan(self):
         return
 
-    @defer.inlineCallbacks
+    @eliotutil.inline_callbacks
     def _process_deque(self):
         # process everything currently in the queue. we're turning it
         # into a list so that if any new items get added while we're
@@ -729,24 +742,21 @@ class QueueMixin(HookMixin):
         # completed)
         self._in_progress.extend(to_process)
 
-        if to_process:
-            self._log("%d items to process" % len(to_process), )
-        for item in to_process:
-            self._process_history.appendleft(item)
-            self._in_progress.remove(item)
-            try:
-                self._log("  processing '%r'" % (item,))
-                proc = yield self._process(item)
-                self._log("  done: %r" % proc)
-                if not proc:
-                    self._process_history.remove(item)
-                self._call_hook(item, 'item_processed')
-            except Exception as e:
-                log.err("processing '%r' failed: %s" % (item, e))
-                item.set_status('failed', self._clock.seconds())
-                proc = Failure()
+        with PROCESS_QUEUE(count=len(to_process)):
+            for item in to_process:
+                self._process_history.appendleft(item)
+                self._in_progress.remove(item)
+                try:
+                    proc = yield self._process(item)
+                    if not proc:
+                        self._process_history.remove(item)
+                    self._call_hook(item, 'item_processed')
+                except:
+                    write_traceback()
+                    item.set_status('failed', self._clock.seconds())
+                    proc = Failure()
 
-            self._call_hook(proc, 'processed')
+                self._call_hook(proc, 'processed')
 
     def _get_relpath(self, filepath):
         self._log("_get_relpath(%r)" % (filepath,))
@@ -1009,8 +1019,8 @@ class Uploader(QueueMixin):
 
     def _process(self, item):
         """
-        process a single QueuedItem. If this returns False, the item is
-        removed from _process_history
+        Possibly upload a single QueuedItem.  If this returns False, the item is
+        removed from _process_history.
         """
         with PROCESS_ITEM(item=item).context():
             d = DeferredContext(defer.succeed(False))
@@ -1542,6 +1552,10 @@ class Downloader(QueueMixin, WriteFileMixin):
                 )
 
     def _process(self, item):
+        """
+        Possibly upload a single QueuedItem.  If this returns False, the item is
+        removed from _process_history.
+        """
         # Downloader
         now = self._clock.seconds()