[CWS] do not send cpu in kevent_t

[paulcacheux]

What does this PR do?

The CPU is not unmarshaled except for perf ring quick info (sorting purposes). This PR removes it since the CPU is already accessible through other ways, winning 8 bytes in every events going in the ring buffer.

Motivation

Additional Notes

Possible Drawbacks / Trade-offs

Describe how to test/QA your changes

[pr-commenter]

Test changes on VM

Use this command from test-infra-definitions to manually test this PR changes on a VM:

inv create-vm --pipeline-id=34725501 --os-family=ubuntu

[pr-commenter]

Regression Detector

Regression Detector Results

Run ID: 68862ed2-5f8e-4a72-aa4d-6f35d2d7e025
Baseline: 3d2fc0c
Comparison: a47a6f7

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

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.

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	pycheck_1000_100byte_tags	% cpu utilization	+4.24	[-0.68, +9.17]
➖	basic_py_check	% cpu utilization	+2.05	[-0.36, +4.47]
➖	file_tree	memory utilization	+0.66	[+0.57, +0.75]
➖	otel_to_otel_logs	ingress throughput	+0.04	[-0.33, +0.41]
➖	trace_agent_json	ingress throughput	+0.01	[-0.01, +0.04]
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.20, +0.20]
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.05, +0.04]
➖	trace_agent_msgpack	ingress throughput	-0.01	[-0.02, -0.01]
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	-0.43	[-3.21, +2.35]
➖	idle	memory utilization	-0.59	[-0.63, -0.56]
➖	tcp_syslog_to_blackhole	ingress throughput	-4.46	[-25.50, +16.58]

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".

[paulcacheux]

/merge

[dd-devflow]

🚂 MergeQueue

This merge request is not mergeable yet, because of pending checks/missing approvals. It will be added to the queue as soon as checks pass and/or get approvals.
Note: if you pushed new commits since the last approval, you may need additional approval.
You can remove it from the waiting list with /remove command.

Use /merge -c to cancel this operation!

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 8 lines in your changes are missing coverage. Please review.

Project coverage is 24.81%. Comparing base (1573b64) to head (a47a6f7).
Report is 2 commits behind head on main.

Files	Patch %	Lines
pkg/security/secl/model/unmarshallers_linux.go	0.00%	5 Missing ⚠️
...kg/security/probe/eventstream/reorderer/perfmap.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main   #25700       +/-   ##
===========================================
- Coverage   44.67%   24.81%   -19.87%     
===========================================
  Files        2282      258     -2024     
  Lines      263636    85758   -177878     
===========================================
- Hits       117782    21277    -96505     
+ Misses     136396    61125    -75271     
+ Partials     9458     3356     -6102     

Flag	Coverage Δ
amzn_aarch64	26.14% <0.00%> (-19.32%)	⬇️
centos_x86_64	26.14% <0.00%> (-19.23%)	⬇️
ubuntu_aarch64	26.14% <0.00%> (-19.33%)	⬇️
ubuntu_x86_64	26.15% <0.00%> (-19.31%)	⬇️
windows_amd64	22.14% <ø> (-28.86%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[dd-devflow]

🚂 MergeQueue

Pull request added to the queue.

This build is next! (estimated merge in less than 57m)

Use /merge -c to cancel this operation!