Performance investigation

[pawelchcki]

What does this PR do?

Motivation

Describe how to test/QA your changes

Reviewer's Checklist

• Changed code has unit tests for its functionality.
• If this interacts with the agent in a new way, a system test has been added.

[pr-commenter]

Benchmarks

Benchmark execution time: 2023-11-23 16:08:26

Comparing candidate commit f6a1336 in PR branch pawel/test_env_mutex_theory with baseline commit 8beb30d in branch main.

Found 13 performance improvements and 4 performance regressions! Performance is the same for 22 metrics, 2 unstable metrics.

scenario:BenchmarkExtractW3C-24

• 🟩 allocations [-1; -1] or [-5.556%; -5.556%]
• 🟩 execution_time [-196.531ns; -166.269ns] or [-7.114%; -6.019%]

scenario:BenchmarkOTelApiWithCustomTags/datadog_otel_api-24

• 🟩 allocated_mem [-490 bytes; -480 bytes] or [-13.547%; -13.262%]
• 🟩 allocations [-6; -6] or [-20.000%; -20.000%]
• 🟩 execution_time [-992.465ns; -938.135ns] or [-19.765%; -18.683%]

scenario:BenchmarkOTelApiWithCustomTags/otel_api-24

• 🟩 allocated_mem [-494 bytes; -481 bytes] or [-10.215%; -9.940%]
• 🟩 allocations [-6; -6] or [-13.636%; -13.636%]
• 🟩 execution_time [-919.887ns; -841.313ns] or [-12.605%; -11.528%]

scenario:BenchmarkPartialFlushing/Disabled-24

• 🟥 allocations [+194738; +197229] or [+6.134%; +6.212%]
• 🟥 execution_time [+20.510ms; +25.766ms] or [+7.285%; +9.152%]

scenario:BenchmarkPartialFlushing/Enabled-24

• 🟥 allocations [+194044; +195335] or [+6.095%; +6.136%]
• 🟥 execution_time [+25.491ms; +31.837ms] or [+9.120%; +11.391%]

scenario:BenchmarkSingleSpanRetention/no-rules-24

• 🟩 execution_time [-11.854µs; -9.881µs] or [-4.719%; -3.934%]

scenario:BenchmarkSingleSpanRetention/with-rules/match-all-24

• 🟩 execution_time [-12.014µs; -9.903µs] or [-4.742%; -3.908%]

scenario:BenchmarkSingleSpanRetention/with-rules/match-half-24

• 🟩 execution_time [-12.234µs; -9.833µs] or [-4.833%; -3.884%]

scenario:BenchmarkTracerAddSpans-24

• 🟩 allocations [-2; -2] or [-8.000%; -8.000%]
• 🟩 execution_time [-234.801ns; -209.599ns] or [-5.834%; -5.207%]

[github-actions]

🚫 [golangci] _{reported by reviewdog 🐶}
File is not gofmt-ed with -s (gofmt)

[github-actions]

🚫 [golangci] _{reported by reviewdog 🐶}
var-declaration: should omit type atomic.Int32 from declaration of var level; it will be inferred from the right-hand side (revive)

[github-actions]

🚫 [golangci] _{reported by reviewdog 🐶}
var-declaration: should omit type atomic.Bool from declaration of var TraceID128BitEnabled; it will be inferred from the right-hand side (revive)