chore(agent-data-plane): update to tokio 1.52.1 and re-enable eager driver handoff

[thieman]

Summary

• Re-applies changes from chore(agent-data-plane): update to tokio 1.52 and enable eager driver handoff #1387 (reverted in revert(agent-data-plane): update to tokio 1.52 and enable eager driver handoff #1405 due to upstream tokio bug tokio-rs/tokio#8056)
• Bumps tokio from 1.52.0 → 1.52.1, which includes the fix for the flaky correctness tests we were seeing
• Re-enables enable_eager_driver_handoff() and enable_alt_timer() in all three runtime builder sites

Test plan

• Run correctness tests to confirm flakiness is resolved with 1.52.1
• Verify no regressions in normal CI

🤖 Generated with Claude Code

[pr-commenter]

Binary Size Analysis (Agent Data Plane)

Target: c4787c3 (baseline) vs f504e3a (comparison) diff
Analysis Type: Stripped binaries (debug symbols excluded)
Baseline Size: 37.09 MiB
Comparison Size: 37.00 MiB
Size Change: -91.81 KiB (-0.24%)
Pass/Fail Threshold: +5%
Result: PASSED ✅

Changes by Module

Module	File Size	Symbols
figment	-112.85 KiB	657
core	+22.49 KiB	17284
piecemeal	+13.16 KiB	42
anon.9939619bfe8bfb192b56a1b7864558c4.15.llvm.12248130204864774867	-12.09 KiB	1
anon.3b479cc647c83ba29012d8c7926b85aa.15.llvm.3139051186277400116	+12.09 KiB	1
http_body_util	-11.89 KiB	237
saluki_common::task::instrument	-9.54 KiB	36
datadog_protos::trace_piecemeal_include::datadog	-8.47 KiB	20
[sections]	-7.96 KiB	7
memory_accounting::allocator::Tracked	+7.19 KiB	77
tokio	+6.74 KiB	5897
saluki_components::common::datadog	+5.86 KiB	352
http	+4.32 KiB	643
agent_data_plane::components::tag_filterlist	-4.23 KiB	46
anon.9939619bfe8bfb192b56a1b7864558c4.14.llvm.12248130204864774867	-4.10 KiB	1
anon.3b479cc647c83ba29012d8c7926b85aa.14.llvm.3139051186277400116	+4.10 KiB	1
bytes	+3.88 KiB	97
saluki_io::net::util	+3.77 KiB	155
serde_json	+3.74 KiB	238
tower	-3.66 KiB	450

Detailed Symbol Changes

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  [NEW]  +161Ki  [NEW]  +161Ki    agent_data_plane::cli::run::handle_run_command::_{{closure}}::hc4c50a51e079975e
  [NEW] +65.2Ki  [NEW] +65.0Ki    saluki_core::topology::built::BuiltTopology::spawn::_{{closure}}::hbcfe0e1b546e6f87
  [NEW] +63.8Ki  [NEW] +63.6Ki    agent_data_plane::run_inner::_{{closure}}::h7b15982b493fc84c
  [NEW] +57.9Ki  [NEW] +57.7Ki    saluki_core::topology::blueprint::TopologyBlueprint::build::_{{closure}}::h63a4a43c250569b3
  [NEW] +57.7Ki  [NEW] +57.5Ki    agent_data_plane::cli::debug::handle_debug_command::_{{closure}}::h183970306d93bed9
  [NEW] +48.2Ki  [NEW] +47.9Ki    _<saluki_components::transforms::apm_stats::ApmStats as saluki_core::components::transforms::Transform>::run::_{{closure}}::h14dba9cde45cd586
  [NEW] +44.0Ki  [NEW] +43.9Ki    _<figment::value::de::ConfiguredValueDe<I> as serde_core::de::Deserializer>::deserialize_struct::h7355bcfc505155e9
  [NEW] +41.8Ki  [NEW] +41.6Ki    saluki_config::ConfigurationLoader::with_default_secrets_resolution::_{{closure}}::h654dc887d6638e21
  [NEW] +39.3Ki  [NEW] +39.2Ki    saluki_env::workload::providers::remote_agent::build_collector::_{{closure}}::hd014a85cff2a5c71
  [NEW] +38.6Ki  [NEW] +38.4Ki    saluki_components::common::datadog::io::run_endpoint_io_loop::_{{closure}}::hea93225365fe4fc6
  [DEL] -39.0Ki  [DEL] -38.8Ki    saluki_components::common::datadog::io::run_endpoint_io_loop::_{{closure}}::h5434ef7a955f5c5e
  [DEL] -39.7Ki  [DEL] -39.5Ki    saluki_env::workload::providers::remote_agent::build_collector::_{{closure}}::h28ff2d07ad18c51b
  [DEL] -41.7Ki  [DEL] -41.5Ki    saluki_config::ConfigurationLoader::with_default_secrets_resolution::_{{closure}}::h84d68ef3446e85bb
  [DEL] -44.0Ki  [DEL] -43.9Ki    _<figment::value::de::ConfiguredValueDe<I> as serde_core::de::Deserializer>::deserialize_struct::h445c89aa25f43822
  [DEL] -48.1Ki  [DEL] -47.9Ki    _<saluki_components::transforms::apm_stats::ApmStats as saluki_core::components::transforms::Transform>::run::_{{closure}}::h3ea5d2d9c7bad8a2
  [DEL] -57.7Ki  [DEL] -57.5Ki    agent_data_plane::cli::debug::handle_debug_command::_{{closure}}::h4c208bdbbcd89e05
  [DEL] -57.9Ki  [DEL] -57.7Ki    saluki_core::topology::blueprint::TopologyBlueprint::build::_{{closure}}::h922a0f6fad9ed58b
  [DEL] -64.5Ki  [DEL] -64.3Ki    agent_data_plane::run_inner::_{{closure}}::h3e37159b0c10a48e
  [DEL] -65.2Ki  [DEL] -65.0Ki    saluki_core::topology::built::BuiltTopology::spawn::_{{closure}}::h49f3d4c7a4032ff0
  -0.4% -89.4Ki  -0.4% -80.4Ki    [57344 Others]
  [DEL]  -162Ki  [DEL]  -162Ki    agent_data_plane::cli::run::handle_run_command::_{{closure}}::h967bbbe4648074fc
  -0.2% -91.8Ki  -0.3% -82.8Ki    TOTAL

[pr-commenter]

Regression Detector (Agent Data Plane)

Regression Detector Results

Run ID: bfc98bb3-d149-4ed6-9e1c-f6072b0c365e

Baseline: c4787c3
Comparison: f504e3a
Diff

Optimization Goals: ✅ No significant changes detected

Experiments ignored for regressions

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

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
❌	otlp_ingest_logs_5mb_memory	memory utilization	+9.44	[+8.90, +9.97]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_cpu	% cpu utilization	+1.49	[-3.30, +6.28]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_throughput	ingress throughput	+0.02	[-0.11, +0.14]	1	(metrics) (profiles) (logs)

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
❌	otlp_ingest_logs_5mb_memory	memory utilization	+9.44	[+8.90, +9.97]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_cpu	% cpu utilization	+7.06	[-25.61, +39.74]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_memory	memory utilization	+2.50	[+2.33, +2.66]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_throughput	ingress throughput	+1.84	[+1.72, +1.96]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_cpu	% cpu utilization	+1.49	[-3.30, +6.28]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_cpu	% cpu utilization	+1.08	[-1.12, +3.29]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_cpu	% cpu utilization	+0.66	[-6.49, +7.81]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_idle	memory utilization	+0.47	[+0.44, +0.51]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_memory	memory utilization	+0.42	[+0.28, +0.57]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_memory	memory utilization	+0.31	[+0.15, +0.48]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_memory	memory utilization	+0.28	[+0.13, +0.43]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_medium	memory utilization	+0.25	[+0.08, +0.42]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_memory	memory utilization	+0.22	[+0.07, +0.37]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_cpu	% cpu utilization	+0.13	[-1.39, +1.64]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_filtering_5mb_memory	memory utilization	+0.10	[-0.15, +0.35]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_throughput	ingress throughput	+0.08	[+0.01, +0.15]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_memory	memory utilization	+0.07	[-0.08, +0.22]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_transform_5mb_throughput	ingress throughput	+0.07	[-0.00, +0.14]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_throughput	ingress throughput	+0.02	[-0.11, +0.14]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_transform_5mb_cpu	% cpu utilization	+0.01	[-1.96, +1.98]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_throughput	ingress throughput	+0.00	[-0.14, +0.15]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_throughput	ingress throughput	+0.00	[-0.06, +0.06]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_throughput	ingress throughput	-0.00	[-0.05, +0.05]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_throughput	ingress throughput	-0.00	[-0.19, +0.19]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_throughput	ingress throughput	-0.01	[-0.05, +0.02]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_low	memory utilization	-0.01	[-0.18, +0.15]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_filtering_5mb_throughput	ingress throughput	-0.06	[-0.13, +0.01]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_transform_5mb_memory	memory utilization	-0.11	[-0.27, +0.06]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_memory	memory utilization	-0.19	[-0.34, -0.04]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_ultraheavy	memory utilization	-0.29	[-0.41, -0.17]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_heavy	memory utilization	-0.55	[-0.68, -0.41]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_filtering_5mb_cpu	% cpu utilization	-1.17	[-3.58, +1.24]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_cpu	% cpu utilization	-1.24	[-58.70, +56.22]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_cpu	% cpu utilization	-1.54	[-7.51, +4.42]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_cpu	% cpu utilization	-2.45	[-55.58, +50.68]	1	(metrics) (profiles) (logs)

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	observed_value	links
✅	quality_gates_rss_dsd_heavy	memory_usage	10/10	117.91MiB ≤ 140MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_low	memory_usage	10/10	39.64MiB ≤ 50MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_medium	memory_usage	10/10	61.47MiB ≤ 75MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_ultraheavy	memory_usage	10/10	174.55MiB ≤ 200MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_idle	memory_usage	10/10	26.92MiB ≤ 40MiB	(metrics) (profiles) (logs)

Explanation

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

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

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".