Reverted fix https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15788

app/models/event.rb

@@ -72,7 +72,7 @@ class Event < ActiveRecord::Base
     # We're using preload for "push_event_payload" as otherwise the association
     # is not always available (depending on the query being built).
     includes(:author, :project, project: :namespace)
-      .preload(:push_event_payload, target: :author)
+      .preload(:target, :push_event_payload)
   end
   scope :for_milestone_id, ->(milestone_id) { where(target_type: "Milestone", target_id: milestone_id) }

changelogs/unreleased/fix-event-target-author-preloading.yml

----
-title: Fix N+1 query when displaying events
-merge_request:
-author:
-type: performance