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Merged
dd-mergequeue merged 1 commit into from
Jan 19, 2026
Merged

fix(sidecar): prefer poll() for channel #1443

dd-mergequeue merged 1 commit into from
Jan 19, 2026

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@bwoebi bwoebi commented Jan 13, 2026

This fixes paninc()'ing on a fd number higher than FD_SETSIZE.

@bwoebi bwoebi requested a review from a team as a code owner January 13, 2026 00:46
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codecov-commenter commented Jan 13, 2026 •
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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.30%. Comparing base (158b594) to head (b63861c).

Additional details and impacted files 
@@            Coverage Diff             @@
##             main    #1443      +/-   ##
==========================================
- Coverage   71.31%   71.30%   -0.01%     
==========================================
  Files         413      413              
  Lines       66155    66157       +2     
==========================================
- Hits        47176    47172       -4     
- Misses      18979    18985       +6
Components Coverage Δ
libdd-crashtracker 58.65% <ø> (ø)
libdd-crashtracker-ffi 14.37% <ø> (ø)
libdd-alloc 98.73% <ø> (ø)
libdd-data-pipeline 86.04% <ø> (ø)
libdd-data-pipeline-ffi 77.01% <ø> (ø)
libdd-common 81.11% <ø> (ø)
libdd-common-ffi 74.19% <ø> (ø)
libdd-telemetry 59.95% <ø> (+0.03%) ⬆️
libdd-telemetry-ffi 21.17% <ø> (ø)
libdd-dogstatsd-client 83.75% <ø> (ø)
datadog-ipc 82.62% <100.00%> (+<0.01%) ⬆️
libdd-profiling 81.04% <ø> (ø)
libdd-profiling-ffi 62.43% <ø> (ø)
datadog-sidecar 35.99% <ø> (ø)
datdog-sidecar-ffi 11.46% <ø> (ø)
spawn-worker 55.18% <ø> (ø)
libdd-tinybytes 92.44% <ø> (ø)
libdd-trace-normalization 82.33% <ø> (ø)
libdd-trace-obfuscation 94.17% <ø> (ø)
libdd-trace-protobuf 61.18% <ø> (ø)
libdd-trace-utils 89.74% <ø> (ø)
datadog-tracer-flare 61.06% <ø> (ø)
libdd-log 75.57% <ø> (ø)
🚀 New features to boost your workflow:
  • ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
  • 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

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pr-commenter bot commented Jan 13, 2026 •
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Benchmarks

Comparison

Benchmark execution time: 2026-01-13 01:21:58

Comparing candidate commit b63861c in PR branch bob/select-vs-poll with baseline commit 158b594 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 57 metrics, 2 unstable metrics.

Candidate

Candidate benchmark details

Group 1

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
sql/obfuscate_sql_string execution_time 89.610µs 89.786µs ± 0.163µs 89.758µs ± 0.040µs 89.795µs 89.962µs 90.377µs 91.329µs 1.75% 5.951 46.500 0.18% 0.012µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
sql/obfuscate_sql_string execution_time [89.764µs; 89.809µs] or [-0.025%; +0.025%] None None None

Group 2

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
two way interface execution_time 17.899µs 23.237µs ± 8.993µs 18.629µs ± 0.604µs 27.079µs 44.166µs 44.770µs 64.110µs 244.15% 1.709 2.128 38.60% 0.636µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
two way interface execution_time [21.991µs; 24.484µs] or [-5.363%; +5.363%] None None None

Group 3

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
benching deserializing traces from msgpack to their internal representation execution_time 61.036ms 61.740ms ± 2.348ms 61.479ms ± 0.094ms 61.541ms 61.813ms 77.503ms 82.801ms 34.68% 8.067 64.278 3.79% 0.166ms 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
benching deserializing traces from msgpack to their internal representation execution_time [61.415ms; 62.065ms] or [-0.527%; +0.527%] None None None

Group 4

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
profile_add_sample2_frames_x1000 execution_time 535.433µs 536.368µs ± 0.386µs 536.354µs ± 0.253µs 536.618µs 536.993µs 537.418µs 537.742µs 0.26% 0.409 0.406 0.07% 0.027µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
profile_add_sample2_frames_x1000 execution_time [536.315µs; 536.422µs] or [-0.010%; +0.010%] None None None

Group 5

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
benching string interning on wordpress profile execution_time 162.010µs 162.875µs ± 0.275µs 162.829µs ± 0.138µs 162.993µs 163.346µs 163.816µs 164.235µs 0.86% 1.299 4.604 0.17% 0.019µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
benching string interning on wordpress profile execution_time [162.837µs; 162.913µs] or [-0.023%; +0.023%] None None None

Group 6

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
benching serializing traces from their internal representation to msgpack execution_time 14.755ms 14.818ms ± 0.040ms 14.814ms ± 0.018ms 14.831ms 14.864ms 14.957ms 15.129ms 2.13% 3.279 19.908 0.27% 0.003ms 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
benching serializing traces from their internal representation to msgpack execution_time [14.812ms; 14.823ms] or [-0.037%; +0.037%] None None None

Group 7

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
receiver_entry_point/report/2597 execution_time 9.672ms 9.946ms ± 0.073ms 9.942ms ± 0.033ms 9.981ms 10.071ms 10.153ms 10.175ms 2.34% -0.332 2.638 0.73% 0.005ms 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
receiver_entry_point/report/2597 execution_time [9.936ms; 9.956ms] or [-0.102%; +0.102%] None None None

Group 8

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
redis/obfuscate_redis_string execution_time 33.877µs 34.503µs ± 1.067µs 33.998µs ± 0.062µs 34.173µs 36.789µs 36.841µs 37.771µs 11.10% 1.702 0.998 3.09% 0.075µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
redis/obfuscate_redis_string execution_time [34.355µs; 34.651µs] or [-0.429%; +0.429%] None None None

Group 9

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
tags/replace_trace_tags execution_time 2.351µs 2.412µs ± 0.016µs 2.414µs ± 0.004µs 2.419µs 2.430µs 2.439µs 2.448µs 1.39% -2.082 5.576 0.66% 0.001µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
tags/replace_trace_tags execution_time [2.410µs; 2.414µs] or [-0.092%; +0.092%] None None None

Group 10

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
concentrator/add_spans_to_concentrator execution_time 10.520ms 10.549ms ± 0.015ms 10.546ms ± 0.008ms 10.555ms 10.575ms 10.596ms 10.616ms 0.66% 1.203 2.426 0.14% 0.001ms 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
concentrator/add_spans_to_concentrator execution_time [10.547ms; 10.551ms] or [-0.020%; +0.020%] None None None

Group 11

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
sdk_test_data/rules-based execution_time 144.020µs 146.322µs ± 1.745µs 146.163µs ± 0.577µs 146.682µs 147.790µs 151.996µs 164.145µs 12.30% 6.408 57.431 1.19% 0.123µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
sdk_test_data/rules-based execution_time [146.080µs; 146.564µs] or [-0.165%; +0.165%] None None None

Group 12

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
normalization/normalize_name/normalize_name/Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Lo... execution_time 186.592µs 186.966µs ± 0.256µs 186.925µs ± 0.110µs 187.042µs 187.293µs 188.191µs 188.258µs 0.71% 2.668 9.975 0.14% 0.018µs 1 200
normalization/normalize_name/normalize_name/Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Lo... throughput 5311869.838op/s 5348571.258op/s ± 7310.610op/s 5349735.266op/s ± 3153.240op/s 5352785.893op/s 5356682.075op/s 5358037.752op/s 5359286.572op/s 0.18% -2.648 9.859 0.14% 516.938op/s 1 200
normalization/normalize_name/normalize_name/bad-name execution_time 17.589µs 17.798µs ± 0.157µs 17.714µs ± 0.078µs 17.974µs 18.020µs 18.039µs 18.057µs 1.94% 0.358 -1.676 0.88% 0.011µs 1 200
normalization/normalize_name/normalize_name/bad-name throughput 55378881.540op/s 56190934.322op/s ± 493780.925op/s 56452670.074op/s ± 249369.222op/s 56625542.379op/s 56722126.179op/s 56791190.326op/s 56853553.774op/s 0.71% -0.353 -1.677 0.88% 34915.584op/s 1 200
normalization/normalize_name/normalize_name/good execution_time 10.093µs 10.162µs ± 0.031µs 10.159µs ± 0.023µs 10.185µs 10.211µs 10.223µs 10.270µs 1.09% 0.107 -0.191 0.31% 0.002µs 1 200
normalization/normalize_name/normalize_name/good throughput 97373425.612op/s 98409050.112op/s ± 303007.429op/s 98430040.868op/s ± 225578.209op/s 98612624.998op/s 98932911.122op/s 99028716.007op/s 99082957.206op/s 0.66% -0.091 -0.209 0.31% 21425.861op/s 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
normalization/normalize_name/normalize_name/Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Lo... execution_time [186.931µs; 187.002µs] or [-0.019%; +0.019%] None None None
normalization/normalize_name/normalize_name/Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Long-.Too-Lo... throughput [5347558.077op/s; 5349584.438op/s] or [-0.019%; +0.019%] None None None
normalization/normalize_name/normalize_name/bad-name execution_time [17.776µs; 17.820µs] or [-0.122%; +0.122%] None None None
normalization/normalize_name/normalize_name/bad-name throughput [56122501.035op/s; 56259367.609op/s] or [-0.122%; +0.122%] None None None
normalization/normalize_name/normalize_name/good execution_time [10.157µs; 10.166µs] or [-0.043%; +0.043%] None None None
normalization/normalize_name/normalize_name/good throughput [98367056.196op/s; 98451044.027op/s] or [-0.043%; +0.043%] None None None

Group 13

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
normalization/normalize_trace/test_trace execution_time 243.981ns 256.077ns ± 14.421ns 248.460ns ± 3.083ns 269.588ns 285.670ns 288.211ns 290.282ns 16.83% 1.112 -0.423 5.62% 1.020ns 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
normalization/normalize_trace/test_trace execution_time [254.078ns; 258.076ns] or [-0.780%; +0.780%] None None None

Group 14

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
write only interface execution_time 1.183µs 3.266µs ± 1.475µs 3.005µs ± 0.036µs 3.048µs 3.684µs 14.324µs 14.845µs 394.03% 6.912 49.528 45.05% 0.104µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
write only interface execution_time [3.062µs; 3.471µs] or [-6.260%; +6.260%] None None None

Group 15

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
ip_address/quantize_peer_ip_address_benchmark execution_time 4.910µs 4.999µs ± 0.042µs 4.979µs ± 0.038µs 5.036µs 5.063µs 5.066µs 5.067µs 1.76% 0.138 -1.272 0.84% 0.003µs 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
ip_address/quantize_peer_ip_address_benchmark execution_time [4.993µs; 5.005µs] or [-0.116%; +0.116%] None None None

Group 16

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
normalization/normalize_service/normalize_service/A0000000000000000000000000000000000000000000000000... execution_time 495.320µs 496.155µs ± 0.566µs 496.092µs ± 0.254µs 496.357µs 496.804µs 497.266µs 502.168µs 1.22% 6.145 61.988 0.11% 0.040µs 1 200
normalization/normalize_service/normalize_service/A0000000000000000000000000000000000000000000000000... throughput 1991364.999op/s 2015503.164op/s ± 2283.388op/s 2015756.158op/s ± 1032.783op/s 2016750.344op/s 2017679.004op/s 2018393.300op/s 2018895.063op/s 0.16% -6.056 60.723 0.11% 161.460op/s 1 200
normalization/normalize_service/normalize_service/Data🐨dog🐶 繋がっ⛰てて execution_time 370.437µs 371.385µs ± 0.263µs 371.378µs ± 0.189µs 371.565µs 371.842µs 372.027µs 372.074µs 0.19% 0.096 0.305 0.07% 0.019µs 1 200
normalization/normalize_service/normalize_service/Data🐨dog🐶 繋がっ⛰てて throughput 2687640.232op/s 2692625.406op/s ± 1906.018op/s 2692674.783op/s ± 1367.191op/s 2694108.544op/s 2695494.614op/s 2696661.648op/s 2699511.823op/s 0.25% -0.091 0.309 0.07% 134.776op/s 1 200
normalization/normalize_service/normalize_service/Test Conversion 0f Weird !@#$%^&**() Characters execution_time 169.370µs 169.982µs ± 0.361µs 169.973µs ± 0.128µs 170.092µs 170.268µs 170.389µs 174.289µs 2.54% 8.464 99.776 0.21% 0.026µs 1 200
normalization/normalize_service/normalize_service/Test Conversion 0f Weird !@#$%^&**() Characters throughput 5737602.109op/s 5882986.805op/s ± 12269.484op/s 5883280.504op/s ± 4445.745op/s 5887881.591op/s 5894948.980op/s 5900765.649op/s 5904235.767op/s 0.36% -8.273 96.854 0.21% 867.584op/s 1 200
normalization/normalize_service/normalize_service/[empty string] execution_time 37.279µs 37.381µs ± 0.055µs 37.374µs ± 0.037µs 37.415µs 37.476µs 37.529µs 37.600µs 0.60% 0.735 0.886 0.15% 0.004µs 1 200
normalization/normalize_service/normalize_service/[empty string] throughput 26596087.635op/s 26751802.292op/s ± 39456.462op/s 26756538.370op/s ± 26703.466op/s 26779901.853op/s 26808181.165op/s 26819211.788op/s 26824871.631op/s 0.26% -0.725 0.856 0.15% 2789.993op/s 1 200
normalization/normalize_service/normalize_service/test_ASCII execution_time 46.172µs 46.339µs ± 0.180µs 46.322µs ± 0.035µs 46.354µs 46.450µs 46.531µs 48.300µs 4.27% 8.579 83.601 0.39% 0.013µs 1 200
normalization/normalize_service/normalize_service/test_ASCII throughput 20703986.727op/s 21580515.501op/s ± 81282.790op/s 21588234.270op/s ± 16158.947op/s 21606197.439op/s 21630431.441op/s 21649732.113op/s 21658095.090op/s 0.32% -8.441 81.488 0.38% 5747.561op/s 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
normalization/normalize_service/normalize_service/A0000000000000000000000000000000000000000000000000... execution_time [496.076µs; 496.233µs] or [-0.016%; +0.016%] None None None
normalization/normalize_service/normalize_service/A0000000000000000000000000000000000000000000000000... throughput [2015186.708op/s; 2015819.620op/s] or [-0.016%; +0.016%] None None None
normalization/normalize_service/normalize_service/Data🐨dog🐶 繋がっ⛰てて execution_time [371.348µs; 371.421µs] or [-0.010%; +0.010%] None None None
normalization/normalize_service/normalize_service/Data🐨dog🐶 繋がっ⛰てて throughput [2692361.250op/s; 2692889.562op/s] or [-0.010%; +0.010%] None None None
normalization/normalize_service/normalize_service/Test Conversion 0f Weird !@#$%^&**() Characters execution_time [169.932µs; 170.032µs] or [-0.029%; +0.029%] None None None
normalization/normalize_service/normalize_service/Test Conversion 0f Weird !@#$%^&**() Characters throughput [5881286.372op/s; 5884687.237op/s] or [-0.029%; +0.029%] None None None
normalization/normalize_service/normalize_service/[empty string] execution_time [37.373µs; 37.388µs] or [-0.020%; +0.020%] None None None
normalization/normalize_service/normalize_service/[empty string] throughput [26746334.005op/s; 26757270.578op/s] or [-0.020%; +0.020%] None None None
normalization/normalize_service/normalize_service/test_ASCII execution_time [46.314µs; 46.364µs] or [-0.054%; +0.054%] None None None
normalization/normalize_service/normalize_service/test_ASCII throughput [21569250.488op/s; 21591780.514op/s] or [-0.052%; +0.052%] None None None

Group 17

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
credit_card/is_card_number/ execution_time 3.894µs 3.912µs ± 0.003µs 3.912µs ± 0.002µs 3.913µs 3.917µs 3.922µs 3.927µs 0.39% 0.139 8.741 0.08% 0.000µs 1 200
credit_card/is_card_number/ throughput 254647998.190op/s 255621029.969op/s ± 200759.255op/s 255650058.779op/s ± 107486.669op/s 255738309.599op/s 255847488.402op/s 255922428.106op/s 256832115.967op/s 0.46% -0.114 8.812 0.08% 14195.823op/s 1 200
credit_card/is_card_number/ 3782-8224-6310-005 execution_time 78.929µs 80.031µs ± 0.536µs 79.996µs ± 0.393µs 80.388µs 80.950µs 81.273µs 81.561µs 1.96% 0.294 -0.365 0.67% 0.038µs 1 200
credit_card/is_card_number/ 3782-8224-6310-005 throughput 12260745.047op/s 12495640.168op/s ± 83459.650op/s 12500622.534op/s ± 61179.597op/s 12560867.987op/s 12624929.689op/s 12656406.051op/s 12669551.540op/s 1.35% -0.263 -0.395 0.67% 5901.488op/s 1 200
credit_card/is_card_number/ 378282246310005 execution_time 74.518µs 74.939µs ± 0.141µs 74.911µs ± 0.079µs 75.017µs 75.215µs 75.333µs 75.458µs 0.73% 0.740 1.115 0.19% 0.010µs 1 200
credit_card/is_card_number/ 378282246310005 throughput 13252359.439op/s 13344160.652op/s ± 25030.745op/s 13349120.496op/s ± 14029.950op/s 13360885.342op/s 13377907.538op/s 13391060.774op/s 13419600.669op/s 0.53% -0.726 1.092 0.19% 1769.941op/s 1 200
credit_card/is_card_number/37828224631 execution_time 3.894µs 3.912µs ± 0.003µs 3.912µs ± 0.001µs 3.913µs 3.917µs 3.918µs 3.919µs 0.18% -0.954 8.043 0.07% 0.000µs 1 200
credit_card/is_card_number/37828224631 throughput 255187693.244op/s 255631905.047op/s ± 178000.564op/s 255641171.017op/s ± 96658.887op/s 255736819.199op/s 255848914.151op/s 255926144.097op/s 256799742.718op/s 0.45% 0.973 8.173 0.07% 12586.541op/s 1 200
credit_card/is_card_number/378282246310005 execution_time 71.486µs 72.043µs ± 0.149µs 72.040µs ± 0.096µs 72.136µs 72.257µs 72.403µs 72.591µs 0.77% 0.011 1.104 0.21% 0.011µs 1 200
credit_card/is_card_number/378282246310005 throughput 13775796.045op/s 13880562.694op/s ± 28800.040op/s 13881269.309op/s ± 18547.554op/s 13899091.347op/s 13924560.158op/s 13948934.605op/s 13988830.472op/s 0.77% 0.009 1.107 0.21% 2036.470op/s 1 200
credit_card/is_card_number/37828224631000521389798 execution_time 52.128µs 52.200µs ± 0.037µs 52.196µs ± 0.021µs 52.217µs 52.267µs 52.309µs 52.322µs 0.24% 0.822 1.020 0.07% 0.003µs 1 200
credit_card/is_card_number/37828224631000521389798 throughput 19112286.074op/s 19157278.448op/s ± 13461.271op/s 19158444.378op/s ± 7548.271op/s 19165762.282op/s 19177263.724op/s 19181756.424op/s 19183421.687op/s 0.13% -0.817 1.009 0.07% 951.856op/s 1 200
credit_card/is_card_number/x371413321323331 execution_time 5.728µs 5.900µs ± 0.055µs 5.898µs ± 0.035µs 5.932µs 5.974µs 6.033µs 6.038µs 2.39% -0.291 0.160 0.92% 0.004µs 1 200
credit_card/is_card_number/x371413321323331 throughput 165608552.249op/s 169507375.290op/s ± 1575161.122op/s 169561727.369op/s ± 993767.442op/s 170565684.091op/s 172366761.915op/s 173460387.508op/s 174570654.663op/s 2.95% 0.349 0.208 0.93% 111380.711op/s 1 200
credit_card/is_card_number_no_luhn/ execution_time 3.894µs 3.911µs ± 0.002µs 3.911µs ± 0.001µs 3.912µs 3.914µs 3.916µs 3.917µs 0.16% -2.161 16.886 0.06% 0.000µs 1 200
credit_card/is_card_number_no_luhn/ throughput 255291813.919op/s 255687821.643op/s ± 146938.625op/s 255690015.312op/s ± 83746.131op/s 255758958.834op/s 255892691.038op/s 255927651.266op/s 256833689.589op/s 0.45% 2.186 17.111 0.06% 10390.130op/s 1 200
credit_card/is_card_number_no_luhn/ 3782-8224-6310-005 execution_time 64.059µs 64.261µs ± 0.082µs 64.244µs ± 0.035µs 64.287µs 64.391µs 64.632µs 64.686µs 0.69% 1.971 7.546 0.13% 0.006µs 1 200
credit_card/is_card_number_no_luhn/ 3782-8224-6310-005 throughput 15459310.994op/s 15561552.864op/s ± 19712.067op/s 15565627.204op/s ± 8453.548op/s 15572699.501op/s 15583361.257op/s 15592896.473op/s 15610613.656op/s 0.29% -1.950 7.431 0.13% 1393.854op/s 1 200
credit_card/is_card_number_no_luhn/ 378282246310005 execution_time 57.375µs 57.514µs ± 0.102µs 57.489µs ± 0.049µs 57.556µs 57.718µs 57.859µs 57.955µs 0.81% 1.627 3.184 0.18% 0.007µs 1 200
credit_card/is_card_number_no_luhn/ 378282246310005 throughput 17254906.939op/s 17387171.293op/s ± 30726.172op/s 17394712.877op/s ± 14683.550op/s 17407411.205op/s 17422365.440op/s 17428782.501op/s 17429190.408op/s 0.20% -1.613 3.126 0.18% 2172.668op/s 1 200
credit_card/is_card_number_no_luhn/37828224631 execution_time 3.892µs 3.911µs ± 0.003µs 3.911µs ± 0.001µs 3.912µs 3.916µs 3.919µs 3.922µs 0.28% -0.671 10.995 0.07% 0.000µs 1 200
credit_card/is_card_number_no_luhn/37828224631 throughput 254982428.450op/s 255674651.979op/s ± 183762.703op/s 255697200.117op/s ± 88248.026op/s 255773937.851op/s 255878234.543op/s 255916830.501op/s 256930672.227op/s 0.48% 0.698 11.156 0.07% 12993.985op/s 1 200
credit_card/is_card_number_no_luhn/378282246310005 execution_time 54.565µs 54.795µs ± 0.145µs 54.761µs ± 0.083µs 54.869µs 55.125µs 55.166µs 55.228µs 0.85% 0.997 0.432 0.26% 0.010µs 1 200
credit_card/is_card_number_no_luhn/378282246310005 throughput 18106614.119op/s 18250058.417op/s ± 48139.474op/s 18261244.163op/s ± 27626.384op/s 18285066.586op/s 18309681.428op/s 18318356.752op/s 18326687.322op/s 0.36% -0.985 0.407 0.26% 3403.975op/s 1 200
credit_card/is_card_number_no_luhn/37828224631000521389798 execution_time 52.122µs 52.199µs ± 0.031µs 52.196µs ± 0.019µs 52.217µs 52.245µs 52.287µs 52.344µs 0.28% 0.966 2.565 0.06% 0.002µs 1 200
credit_card/is_card_number_no_luhn/37828224631000521389798 throughput 19104291.321op/s 19157512.166op/s ± 11284.244op/s 19158373.644op/s ± 7131.569op/s 19165155.830op/s 19173850.799op/s 19176905.314op/s 19185622.295op/s 0.14% -0.960 2.541 0.06% 797.917op/s 1 200
credit_card/is_card_number_no_luhn/x371413321323331 execution_time 5.730µs 5.907µs ± 0.056µs 5.903µs ± 0.033µs 5.936µs 5.997µs 6.033µs 6.037µs 2.27% -0.164 0.210 0.94% 0.004µs 1 200
credit_card/is_card_number_no_luhn/x371413321323331 throughput 165637761.180op/s 169300883.891op/s ± 1594627.256op/s 169399451.117op/s ± 941810.237op/s 170288813.818op/s 171686635.610op/s 173727639.546op/s 174512977.804op/s 3.02% 0.226 0.276 0.94% 112757.175op/s 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
credit_card/is_card_number/ execution_time [3.912µs; 3.912µs] or [-0.011%; +0.011%] None None None
credit_card/is_card_number/ throughput [255593206.667op/s; 255648853.271op/s] or [-0.011%; +0.011%] None None None
credit_card/is_card_number/ 3782-8224-6310-005 execution_time [79.957µs; 80.106µs] or [-0.093%; +0.093%] None None None
credit_card/is_card_number/ 3782-8224-6310-005 throughput [12484073.463op/s; 12507206.873op/s] or [-0.093%; +0.093%] None None None
credit_card/is_card_number/ 378282246310005 execution_time [74.920µs; 74.959µs] or [-0.026%; +0.026%] None None None
credit_card/is_card_number/ 378282246310005 throughput [13340691.631op/s; 13347629.672op/s] or [-0.026%; +0.026%] None None None
credit_card/is_card_number/37828224631 execution_time [3.911µs; 3.912µs] or [-0.010%; +0.010%] None None None
credit_card/is_card_number/37828224631 throughput [255607235.881op/s; 255656574.213op/s] or [-0.010%; +0.010%] None None None
credit_card/is_card_number/378282246310005 execution_time [72.023µs; 72.064µs] or [-0.029%; +0.029%] None None None
credit_card/is_card_number/378282246310005 throughput [13876571.285op/s; 13884554.102op/s] or [-0.029%; +0.029%] None None None
credit_card/is_card_number/37828224631000521389798 execution_time [52.194µs; 52.205µs] or [-0.010%; +0.010%] None None None
credit_card/is_card_number/37828224631000521389798 throughput [19155412.846op/s; 19159144.051op/s] or [-0.010%; +0.010%] None None None
credit_card/is_card_number/x371413321323331 execution_time [5.892µs; 5.908µs] or [-0.128%; +0.128%] None None None
credit_card/is_card_number/x371413321323331 throughput [169289073.108op/s; 169725677.472op/s] or [-0.129%; +0.129%] None None None
credit_card/is_card_number_no_luhn/ execution_time [3.911µs; 3.911µs] or [-0.008%; +0.008%] None None None
credit_card/is_card_number_no_luhn/ throughput [255667457.363op/s; 255708185.923op/s] or [-0.008%; +0.008%] None None None
credit_card/is_card_number_no_luhn/ 3782-8224-6310-005 execution_time [64.250µs; 64.272µs] or [-0.018%; +0.018%] None None None
credit_card/is_card_number_no_luhn/ 3782-8224-6310-005 throughput [15558820.962op/s; 15564284.767op/s] or [-0.018%; +0.018%] None None None
credit_card/is_card_number_no_luhn/ 378282246310005 execution_time [57.500µs; 57.528µs] or [-0.025%; +0.025%] None None None
credit_card/is_card_number_no_luhn/ 378282246310005 throughput [17382912.941op/s; 17391429.645op/s] or [-0.024%; +0.024%] None None None
credit_card/is_card_number_no_luhn/37828224631 execution_time [3.911µs; 3.912µs] or [-0.010%; +0.010%] None None None
credit_card/is_card_number_no_luhn/37828224631 throughput [255649184.236op/s; 255700119.723op/s] or [-0.010%; +0.010%] None None None
credit_card/is_card_number_no_luhn/378282246310005 execution_time [54.775µs; 54.815µs] or [-0.037%; +0.037%] None None None
credit_card/is_card_number_no_luhn/378282246310005 throughput [18243386.749op/s; 18256730.085op/s] or [-0.037%; +0.037%] None None None
credit_card/is_card_number_no_luhn/37828224631000521389798 execution_time [52.195µs; 52.203µs] or [-0.008%; +0.008%] None None None
credit_card/is_card_number_no_luhn/37828224631000521389798 throughput [19155948.279op/s; 19159076.054op/s] or [-0.008%; +0.008%] None None None
credit_card/is_card_number_no_luhn/x371413321323331 execution_time [5.899µs; 5.915µs] or [-0.130%; +0.130%] None None None
credit_card/is_card_number_no_luhn/x371413321323331 throughput [169079883.889op/s; 169521883.892op/s] or [-0.131%; +0.131%] None None None

Group 18

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
profile_add_sample_frames_x1000 execution_time 3.984ms 3.991ms ± 0.007ms 3.990ms ± 0.002ms 3.992ms 3.995ms 3.999ms 4.079ms 2.23% 11.356 146.203 0.17% 0.000ms 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
profile_add_sample_frames_x1000 execution_time [3.990ms; 3.992ms] or [-0.023%; +0.023%] None None None

Group 19

cpu_model git_commit_sha git_commit_date git_branch
Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz b63861c 1768266278 bob/select-vs-poll
scenario metric min mean ± sd median ± mad p75 p95 p99 max peak_to_median_ratio skewness kurtosis cv sem runs sample_size
single_flag_killswitch/rules-based execution_time 187.757ns 190.471ns ± 2.339ns 190.257ns ± 1.667ns 191.643ns 195.032ns 196.494ns 199.977ns 5.11% 1.189 1.403 1.22% 0.165ns 1 200
scenario metric 95% CI mean Shapiro-Wilk pvalue Ljung-Box pvalue (lag=1) Dip test pvalue
single_flag_killswitch/rules-based execution_time [190.146ns; 190.795ns] or [-0.170%; +0.170%] None None None

Baseline

Omitted due to size.

@bwoebi
Prefer poll() for sidecar channel
b63861c 
This fixes paninc()'ing on a fd number higher than FD_SETSIZE.

Signed-off-by: Bob Weinand <bob.weinand@datadoghq.com>
@bwoebi bwoebi force-pushed the bob/select-vs-poll branch from 431fef2 to b63861c Compare January 13, 2026 01:04
@morrisonlevi morrisonlevi changed the title Prefer poll() for sidecar channel fix: prefer poll() for sidecar channel Jan 13, 2026
@morrisonlevi morrisonlevi changed the title fix: prefer poll() for sidecar channel fix(sidecar): prefer poll() for channel Jan 13, 2026
morrisonlevi
morrisonlevi reviewed Jan 13, 2026
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How does using poll fix the issue? I think a comment is warranted here.

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dd-octo-sts bot commented Jan 19, 2026

Artifact Size Benchmark Report

aarch64-alpine-linux-musl
Artifact Baseline Commit Change
/aarch64-alpine-linux-musl/lib/libdatadog_profiling.so 7.57 MB 7.57 MB 0% (0 B) 👌
/aarch64-alpine-linux-musl/lib/libdatadog_profiling.a 87.80 MB 87.80 MB 0% (0 B) 👌
aarch64-apple-darwin
Artifact Baseline Commit Change
/aarch64-apple-darwin/lib/libdatadog_profiling.a 59.43 MB 59.43 MB 0% (0 B) 👌
/aarch64-apple-darwin/lib/libdatadog_profiling.dylib 8.58 MB 8.58 MB 0% (0 B) 👌
aarch64-unknown-linux-gnu
Artifact Baseline Commit Change
/aarch64-unknown-linux-gnu/lib/libdatadog_profiling.a 101.52 MB 101.52 MB 0% (0 B) 👌
/aarch64-unknown-linux-gnu/lib/libdatadog_profiling.so 9.71 MB 9.71 MB 0% (0 B) 👌
libdatadog-x64-windows
Artifact Baseline Commit Change
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.dll 20.43 MB 20.43 MB 0% (0 B) 👌
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.lib 73.49 KB 73.49 KB 0% (0 B) 👌
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.pdb 151.29 MB 151.27 MB --.01% (-16.00 KB) 💪
/libdatadog-x64-windows/debug/static/datadog_profiling_ffi.lib 817.84 MB 817.84 MB 0% (0 B) 👌
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.dll 6.51 MB 6.51 MB 0% (0 B) 👌
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.lib 73.49 KB 73.49 KB 0% (0 B) 👌
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.pdb 20.14 MB 20.14 MB 0% (0 B) 👌
/libdatadog-x64-windows/release/static/datadog_profiling_ffi.lib 39.52 MB 39.52 MB 0% (0 B) 👌
libdatadog-x86-windows
Artifact Baseline Commit Change
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.dll 17.43 MB 17.43 MB 0% (0 B) 👌
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.lib 74.62 KB 74.62 KB 0% (0 B) 👌
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.pdb 154.16 MB 154.16 MB +0% (+8.00 KB) 👌
/libdatadog-x86-windows/debug/static/datadog_profiling_ffi.lib 805.63 MB 805.63 MB 0% (0 B) 👌
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.dll 5.01 MB 5.01 MB 0% (0 B) 👌
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.lib 74.62 KB 74.62 KB 0% (0 B) 👌
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.pdb 21.46 MB 21.46 MB 0% (0 B) 👌
/libdatadog-x86-windows/release/static/datadog_profiling_ffi.lib 37.29 MB 37.29 MB 0% (0 B) 👌
x86_64-alpine-linux-musl
Artifact Baseline Commit Change
/x86_64-alpine-linux-musl/lib/libdatadog_profiling.a 76.05 MB 76.05 MB 0% (0 B) 👌
/x86_64-alpine-linux-musl/lib/libdatadog_profiling.so 9.00 MB 9.00 MB 0% (0 B) 👌
x86_64-apple-darwin
Artifact Baseline Commit Change
/x86_64-apple-darwin/lib/libdatadog_profiling.a 60.76 MB 60.76 MB 0% (0 B) 👌
/x86_64-apple-darwin/lib/libdatadog_profiling.dylib 9.63 MB 9.63 MB 0% (0 B) 👌
x86_64-unknown-linux-gnu
Artifact Baseline Commit Change
/x86_64-unknown-linux-gnu/lib/libdatadog_profiling.a 95.61 MB 95.61 MB 0% (0 B) 👌
/x86_64-unknown-linux-gnu/lib/libdatadog_profiling.so 10.45 MB 10.45 MB 0% (0 B) 👌

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realFlowControl commented Jan 19, 2026 •
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How does using poll fix the issue? I think a comment is warranted here.

poll() fixes the issue, as poll() is not bound to the FD_SETSIZE limit like select() is, see the manpage:

WARNING: select() can monitor only file descriptors numbers that are less than FD_SETSIZE (1024)—an unreasonably low limit for many modern applications—and this limitation will not change. All modern applications should instead use poll(2) or epoll(7), which do not suffer this limitation.

@bwoebi
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bwoebi commented Jan 19, 2026

/merge

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gh-worker-devflow-routing-ef8351 bot commented Jan 19, 2026 •
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2026-01-19 16:04:47 UTC ℹ️ Start processing command /merge

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2026-01-19 16:09:00 UTC ℹ️ MergeQueue: merge request added to the queue

The expected merge time in main is approximately 29m (p90).

2026-01-19 17:23:56 UTC ℹ️ MergeQueue: Readding this merge request to the queue because another merge request processed with yours failed. No action is needed from your side.

2026-01-19 18:02:34 UTC ℹ️ MergeQueue: This merge request was merged

@dd-mergequeue dd-mergequeue bot merged commit f3661d2 into main Jan 19, 2026
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@dd-mergequeue dd-mergequeue bot deleted the bob/select-vs-poll branch January 19, 2026 18:02
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