Rename to total_duration and we're not using CommitStatus.duration

app/models/ci/pipeline.rb

@@ -78,7 +78,7 @@ module Ci
       CommitStatus.where(pipeline: pluck(:id)).stages
     end
 
-    def self.duration
+    def self.total_duration
       where.not(duration: nil).sum(:duration)
     end
 

app/models/commit_status.rb

@@ -103,11 +103,6 @@ class CommitStatus < ActiveRecord::Base
     end
   end
 
-  def self.duration
-    select(:started_at, :finished_at).all.
-      map(&:duration).compact.inject(0, &:+)
-  end
-
   def ignored?
     allow_failure? && (failed? || canceled?)
   end

app/views/projects/commit/_commit_box.html.haml

@@ -57,9 +57,8 @@
     = link_to builds_namespace_project_commit_path(@project.namespace, @project, @commit.id), class: "ci-status-link ci-status-icon-#{@commit.status}" do
       = ci_icon_for_status(@commit.status)
       = ci_label_for_status(@commit.status)
-    - if @commit.pipelines.duration
     in
-      = time_interval_in_words @commit.pipelines.duration
+    = time_interval_in_words @commit.pipelines.total_duration
 
 .commit-box.content-block
   %h3.commit-title