blob: fd8ca3b37c634eb56047f6ad9160b18ca90bf217 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
# frozen_string_literal: true
require 'fast_spec_helper'
RSpec.describe Gitlab::Metrics::Memory do
describe '.gc_heap_fragmentation' do
subject(:call) do
described_class.gc_heap_fragmentation(
heap_live_slots: gc_stat_heap_live_slots,
heap_eden_pages: gc_stat_heap_eden_pages
)
end
context 'when the Ruby heap is perfectly utilized' do
# All objects are located in a single heap page.
let(:gc_stat_heap_live_slots) { described_class::HEAP_SLOTS_PER_PAGE }
let(:gc_stat_heap_eden_pages) { 1 }
it { is_expected.to eq(0) }
end
context 'when the Ruby heap is greatly fragmented' do
# There is one object per heap page.
let(:gc_stat_heap_live_slots) { described_class::HEAP_SLOTS_PER_PAGE }
let(:gc_stat_heap_eden_pages) { described_class::HEAP_SLOTS_PER_PAGE }
# The heap can never be "perfectly fragmented" because that would require
# zero objects per page.
it { is_expected.to be > 0.99 }
end
context 'when the Ruby heap is semi-fragmented' do
# All objects are spread over two pages i.e. each page is 50% utilized.
let(:gc_stat_heap_live_slots) { described_class::HEAP_SLOTS_PER_PAGE }
let(:gc_stat_heap_eden_pages) { 2 }
it { is_expected.to eq(0.5) }
end
end
end
|