Remove GC metrics from performance bar

These were disabled in production mode, but that also broke the rest of
the performance bar. As they were only enabled in development mode, we
can just remove them for now.

Gemfile

@@ -296,7 +296,6 @@ gem 'batch-loader', '~> 1.4.0'
 
 # Perf bar
 gem 'peek', '~> 1.0.1'
-gem 'peek-gc', '~> 0.0.2'
 
 # Memory benchmarks
 gem 'derailed_benchmarks', require: false

Gemfile.lock

@@ -641,8 +641,6 @@ GEM
       concurrent-ruby (>= 0.9.0)
       concurrent-ruby-ext (>= 0.9.0)
       railties (>= 4.0.0)
-    peek-gc (0.0.2)
-      peek
     pg (1.1.4)
     po_to_json (1.0.1)
       json (>= 1.6.0)
@@ -1173,7 +1171,6 @@ DEPENDENCIES
   omniauth_openid_connect (~> 0.3.1)
   org-ruby (~> 0.9.12)
   peek (~> 1.0.1)
-  peek-gc (~> 0.0.2)
   pg (~> 1.1)
   premailer-rails (~> 1.9.7)
   prometheus-client-mmap (~> 0.9.8)

app/assets/javascripts/performance_bar/components/performance_bar_app.vue

@@ -112,12 +112,6 @@ export default {
         :header="metric.header"
         :keys="metric.keys"
       />
-      <div id="peek-view-gc" class="view">
-        <span v-if="currentRequest.details" class="bold">
-          <span title="Invoke Time">{{ currentRequest.details.gc.gc_time }}</span
-          >ms / <span title="Invoke Count">{{ currentRequest.details.gc.invokes }}</span> gc
-        </span>
-      </div>
       <div
         v-if="currentRequest.details && currentRequest.details.tracing"
         id="peek-view-trace"

changelogs/unreleased/remove-peek-gc.yml

+---
+title: Remove GC metrics from performance bar
+merge_request:
+author:
+type: removed

config/initializers/peek.rb

@@ -10,9 +10,4 @@ Peek.into Peek::Views::Gitaly
 Peek.into Peek::Views::RedisDetailed
 Peek.into Peek::Views::Rugged
 
-# `Peek::Views::GC` is currently disabled in production, as it runs with every request
-# even if PerformanceBar is inactive and clears `GC::Profiler` reports we need for metrics.
-# Check https://gitlab.com/gitlab-org/gitlab-ce/issues/65455
-Peek.into Peek::Views::GC if Rails.env.development?
-
 Peek.into Peek::Views::Tracing if Labkit::Tracing.tracing_url_enabled?

doc/administration/monitoring/performance/performance_bar.md

@@ -16,7 +16,6 @@ It allows you to see (from left to right):
   ![Rugged profiling using the Performance Bar](img/performance_bar_rugged_calls.png)
 - time taken and number of Redis calls, click through for details of these calls
   ![Redis profiling using the Performance Bar](img/performance_bar_redis_calls.png)
-- time taken and number of Ruby GC calls
 
 On the far right is a request selector that allows you to view the same metrics
 (excluding the page timing and line profiler) for any requests made while the