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| author | Peter Zhu <peter@peterzhu.ca> | 2023-04-03 13:43:31 -0400 |
|---|---|---|
| committer | Peter Zhu <peter@peterzhu.ca> | 2023-05-24 12:11:48 -0400 |
| commit | a23ae56c4d24ade9438393fc47d6f2b730e3f7a8 (patch) | |
| tree | 0567f6a4719d7b0ff6d105b401930dc426a69d05 /test | |
| parent | 6d976eb5348098a346d82065621e37925acae8b8 (diff) | |
Add REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO
[Feature #19571]
This commit adds the environment variable
`RUBY_GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO` which is
used to calculate the `remembered_wb_unprotected_objects_limit` using a
ratio of `old_objects`. This should improve performance by reducing
major GC because, in a major GC, we mark all of the old objects, so we
should have more uncollectible WB unprotected objects before starting a
major GC. The default has been set to 0.01 (1% of old objects).
On one of [Shopify's highest traffic Ruby apps, Storefront Renderer](https://shopify.engineering/how-shopify-reduced-storefront-response-times-rewrite),
we saw significant improvements after deploying this patch in
production. In the graphs below, we have the `tuned` group which uses
`RUBY_GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO=0.01` (the
default value), and an `untuned` group, which turns this feature off
with `RUBY_GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO=0`. We
see that the tuned group spends significantly less time in GC, on
average 0.67x of the time compared to the untuned group and 0.49x for
p99. We see this improvement in GC time translate to improvements in
response times. The average response time is now 0.96x of the time
compared to the untuned group and 0.86x for p99.
https://user-images.githubusercontent.com/15860699/229559078-e23e8ce4-5f1f-4a2f-b5ef-5769f92b8c70.png
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/7577
Diffstat (limited to 'test')
| -rw-r--r-- | test/ruby/test_gc.rb | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/test/ruby/test_gc.rb b/test/ruby/test_gc.rb index 4f1d32580a..3ff2d8bff2 100644 --- a/test/ruby/test_gc.rb +++ b/test/ruby/test_gc.rb @@ -383,6 +383,15 @@ class TestGc < Test::Unit::TestCase assert_in_out_err([env, "-w", "-e", "exit"], "", [], /RUBY_GC_OLDMALLOC_LIMIT_MAX=16000000/, "") assert_in_out_err([env, "-w", "-e", "exit"], "", [], /RUBY_GC_OLDMALLOC_LIMIT_GROWTH_FACTOR=2.0/, "") end + + ["0.01", "0.1", "1.0"].each do |i| + env = {"RUBY_GC_HEAP_OLDOBJECT_LIMIT_FACTOR" => "0", "RUBY_GC_HEAP_REMEMBERED_WB_UNPROTECTED_OBJECTS_LIMIT_RATIO" => i} + assert_separately([env, "-W0"], __FILE__, __LINE__, <<~RUBY) + GC.disable + GC.start + assert_equal((GC.stat[:old_objects] * #{i}).to_i, GC.stat[:remembered_wb_unprotected_objects_limit]) + RUBY + end end def test_profiler_enabled |