diff --git a/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php b/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php
--- a/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php
+++ b/src/applications/repository/engine/PhabricatorRepositoryDiscoveryEngine.php
@@ -682,7 +682,32 @@
 
     $data['commitID'] = $commit->getID();
 
-    PhabricatorWorker::scheduleTask($class, $data);
+    // If the repository is importing for the first time, we schedule tasks
+    // at IMPORT priority, which is very low. Making progress on importing a
+    // new repository for the first time is less important than any other
+    // daemon task.
+
+    // If the repostitory has finished importing and we're just catching up
+    // on recent commits, we schedule discovery at COMMIT priority, which is
+    // slightly below the default priority.
+
+    // Note that followup tasks and triggered tasks (like those generated by
+    // Herald or Harbormaster) will queue at DEFAULT priority, so that each
+    // commit tends to fully import before we start the next one. This tends
+    // to give imports fairly predictable progress. See T11677 for some
+    // discussion.
+
+    if ($repository->isImporting()) {
+      $task_priority = PhabricatorWorker::PRIORITY_IMPORT;
+    } else {
+      $task_priority = PhabricatorWorker::PRIORITY_COMMIT;
+    }
+
+    $options = array(
+      'priority' => $task_priority,
+    );
+
+    PhabricatorWorker::scheduleTask($class, $data, $options);
   }
 
   private function isInitialImport(array $refs) {
diff --git a/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php b/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
--- a/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
+++ b/src/applications/repository/worker/commitmessageparser/PhabricatorRepositoryCommitMessageParserWorker.php
@@ -47,6 +47,14 @@
         $this->getFollowupTaskClass(),
         array(
           'commitID' => $commit->getID(),
+        ),
+        array(
+          // We queue followup tasks at default priority so that the queue
+          // finishes work it has started before starting more work. If
+          // followups are queued at the same priority level, we do all
+          // message parses first, then all change parses, etc. This makes
+          // progress uneven. See T11677 for discussion.
+          'priority' => PhabricatorWorker::PRIORITY_DEFAULT,
         ));
     }
   }
diff --git a/src/infrastructure/daemon/workers/PhabricatorWorker.php b/src/infrastructure/daemon/workers/PhabricatorWorker.php
--- a/src/infrastructure/daemon/workers/PhabricatorWorker.php
+++ b/src/infrastructure/daemon/workers/PhabricatorWorker.php
@@ -16,6 +16,7 @@
 
   const PRIORITY_ALERTS  = 1000;
   const PRIORITY_DEFAULT = 2000;
+  const PRIORITY_COMMIT  = 2500;
   const PRIORITY_BULK    = 3000;
   const PRIORITY_IMPORT  = 4000;