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[usm] Use `ebpf.Modifer` for patching helper calls

Open p-lambert opened this issue 11 months ago • 1 comments

What does this PR do?

Use ebpf.Modfier introduced in https://github.com/DataDog/datadog-agent/pull/23158 for removing calls to bpf_ringbuf_output.

Motivation

Remove code duplication.

Additional Notes

Ideally we should favor the use ddebpf.Manager to control the execution of the ebpf.Modifer but this is a big refactoring that I'm leaving for a future PR.

Possible Drawbacks / Trade-offs

Describe how to test/QA your changes

p-lambert avatar Mar 07 '24 17:03 p-lambert

Bloop Bleep... Dogbot Here

Regression Detector Results

Run ID: 59eaa581-d3b0-465e-97f4-060ea1498202 Baseline: dd8188170eb12b0964a29426cf42fc8bd9e9c69b Comparison: af6535e665f20d702f0fdb1b5b6308ec92c35d24

Performance changes are noted in the perf column of each table:

  • ✅ = significantly better comparison variant performance
  • ❌ = significantly worse comparison variant performance
  • ➖ = no significant change in performance

Experiments with missing or malformed data

  • basic_py_check

Usually, this warning means that there is no usable optimization goal data for that experiment, which could be a result of misconfiguration.

No significant changes in experiment optimization goals

Confidence level: 90.00% Effect size tolerance: |Δ mean %| ≥ 5.00%

There were no significant changes in experiment optimization goals at this confidence level and effect size tolerance.

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf experiment goal Δ mean % Δ mean % CI
file_to_blackhole % cpu utilization +0.06 [-6.48, +6.61]

Fine details of change detection per experiment

perf experiment goal Δ mean % Δ mean % CI
uds_dogstatsd_to_api_cpu % cpu utilization +0.65 [-0.82, +2.11]
otel_to_otel_logs ingress throughput +0.55 [-0.10, +1.19]
tcp_syslog_to_blackhole ingress throughput +0.42 [+0.36, +0.47]
file_to_blackhole % cpu utilization +0.06 [-6.48, +6.61]
trace_agent_msgpack ingress throughput +0.01 [-0.01, +0.03]
tcp_dd_logs_filter_exclude ingress throughput +0.00 [-0.00, +0.00]
uds_dogstatsd_to_api ingress throughput +0.00 [-0.00, +0.00]
trace_agent_json ingress throughput -0.00 [-0.02, +0.02]
process_agent_standard_check memory utilization -0.03 [-0.06, +0.01]
process_agent_standard_check_with_stats memory utilization -0.05 [-0.08, -0.02]
process_agent_real_time_mode memory utilization -0.07 [-0.11, -0.04]
idle memory utilization -0.15 [-0.19, -0.12]
file_tree memory utilization -0.40 [-0.47, -0.32]

Explanation

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

  1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

  2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

  3. Its configuration does not mark it "erratic".

pr-commenter[bot] avatar Mar 07 '24 19:03 pr-commenter[bot]

/merge

p-lambert avatar Mar 11 '24 13:03 p-lambert

:steam_locomotive: MergeQueue

Pull request added to the queue.

This build is going to start soon! (estimated merge in less than 27m)

Use /merge -c to cancel this operation!

dd-devflow[bot] avatar Mar 11 '24 13:03 dd-devflow[bot]