feat(wall): support signal suppression for unfiltered threads by kaahos · Pull Request #663 · DataDog/java-profiler

kaahos · 2026-07-16T13:30:31Z

What does this PR do?:

Extends wall-clock signal suppression to threads sampled through the existing explicit filter= mode.

When wall profiling runs with both filter= and wallprecheck=true, the profiler now:

Tracks thread identity and lifecycle independently from context-filter membership.
Registers Java threads that already exist when profiling starts.
Registers new threads through the existing thread lifecycle callbacks.
Allows block and park hooks to lazily associate pre-existing threads with their registry slots.
Makes the thread metadata available to both the ASGCT and JVMTI wall-clock paths.
Suppresses repeated samples only for profiler-owned blocking runs that remain outside the context window.
Validates thread identity, slot lifecycle, and context transitions before applying suppression.

The existing context-filtered behavior remains unchanged. This PR does not change the meaning of filter=.

Motivation:

With filter=, wall-clock profiling already samples every thread. However, threads outside an active context did not have the lifecycle metadata required to recognize and suppress repeated samples from the same profiler-owned blocking run.

This change closes that metadata gap. It also provides the thread lifecycle machinery needed by the follow-up TaskBlock work for non-context threads.

Implementation notes:

Thread identity is indexed by native TID while context-window membership remains separate.
Lifecycle generations prevent reused slots or TIDs from inheriting stale state.
Context-window epochs prevent suppression if a thread enters or leaves a context during a blocking run.
Registry tracking is activated only for wall recordings using explicit filter= together with wallprecheck=true.
Tracking is disabled again when wall profiling is absent, precheck is disabled, wall startup fails, or a later recording uses another configuration.
Both ASGCT and JVMTI wall-clock collection paths use the same registry validation.

How to test the change?:

./.claude/commands/build-and-summarize :ddprof-lib:gtestDebug_threadFilter_ut :ddprof-lib:gtestDebug_wallprecheck_args_ut
./.claude/commands/build-and-summarize :ddprof-test:testDebug -Ptests="*UnfilteredWallPrecheck*"
./.claude/commands/build-and-summarize testDebug

For Datadog employees:

If this PR touches code that signs or publishes builds or packages, or handles credentials
of any kind, I've requested a security review.
This PR doesn't touch any of that.
JIRA: [JIRA-XXXX]

dd-octo-sts · 2026-07-16T13:51:39Z

CI Test Results

Run: #36609406833 | Commit: 4d55a0d | Duration: 22m 2s (longest job)

❌ 9 of 76 test jobs failed

Status Overview

JDK	glibc-aarch64/asan	glibc-aarch64/debug	glibc-aarch64/tsan	glibc-amd64/asan	glibc-amd64/debug	glibc-amd64/tsan	musl-aarch64/debug	musl-amd64/debug
8	-	-	-	❌	✅	✅	-	-
8-ibm	-	-	-	✅	✅	✅	-	-
8-j9	✅	✅	✅	✅	✅	✅	-	-
8-librca	-	-	-	-	-	-	✅	✅
8-orcl	-	-	-	❌	✅	✅	-	-
11	-	-	-	❌	✅	✅	-	-
11-j9	✅	✅	✅	✅	✅	✅	-	-
11-librca	-	-	-	-	-	-	✅	✅
17	❌	✅	✅	❌	✅	✅	-	-
17-graal	✅	✅	✅	✅	✅	✅	-	-
17-j9	✅	✅	✅	✅	✅	✅	-	-
17-librca	-	-	-	-	-	-	✅	✅
21	❌	✅	✅	❌	✅	✅	-	-
21-graal	✅	✅	✅	✅	✅	✅	-	-
21-librca	-	-	-	-	-	-	✅	✅
25	❌	✅	✅	❌	✅	✅	-	-
25-graal	✅	✅	✅	✅	✅	✅	-	-
25-librca	-	-	-	-	-	-	✅	✅

Legend: ✅ passed | ❌ failed | ⚪ skipped | 🚫 cancelled

❌ Failing tests

Test	Cells	Message
`MegamorphicCallTest._5_`	`glibc-21-asan-amd64`	`org.opentest4j.AssertionFailedError: Test execution #5 (of up to 5 with at least 1 successes) failed ~> test fails - see`

Retried 9 of 70 cells.

Failed Jobs

glibc-aarch64/asan / 17 — view logs
glibc-aarch64/asan / 25 — view logs
glibc-amd64/asan / 8-orcl — view logs
glibc-aarch64/asan / 21 — view logs
glibc-amd64/asan / 8 — view logs
glibc-amd64/asan / 11 — view logs
glibc-amd64/asan / 17 — view logs
glibc-amd64/asan / 21 — view logs
glibc-amd64/asan / 25 — view logs

Summary: Total: 76 | Passed: 67 | Failed: 9

Updated: 2026-09-29 18:28:39 UTC

dd-octo-sts · 2026-07-19T19:14:40Z

Benchmark Results (commit `fb1c44d`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125547869 Commit: fb1c44de77197780eae60267ff98bd38a907a558

⚠️ Significant outliers

🔴 fj-kmeans (JDK 21): runtime +5.9% (2679→2836 ms)
🔴 future-genetic (JDK 21): runtime +3.8% (2083→2162 ms)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10210 ms (21 iters)	✅ 10256 ms (21 iters)	≈ +0.5% (±10.9%)	— / —
akka-uct	25	✅ 8953 ms (24 iters)	✅ 8890 ms (24 iters)	≈ -0.7% (±10.2%)	— / —
finagle-chirper	21	✅ 6000 ms (33 iters)	✅ 5960 ms (33 iters)	≈ -0.7% (±25.4%)	⚠️ W:3 / ⚠️ W:3
finagle-chirper	25	✅ 5431 ms (36 iters)	✅ 5443 ms (36 iters)	≈ +0.2% (±24.6%)	⚠️ W:4 / ⚠️ W:3
fj-kmeans	21	✅ 2679 ms (70 iters)	✅ 2836 ms (66 iters)	🔴 +5.9%	— / —
fj-kmeans	25	✅ 2847 ms (66 iters)	✅ 2828 ms (66 iters)	≈ -0.7% (±2.6%)	— / —
future-genetic	21	✅ 2083 ms (89 iters)	✅ 2162 ms (86 iters)	🔴 +3.8%	— / —
future-genetic	25	✅ 2076 ms (90 iters)	✅ 2122 ms (88 iters)	≈ +2.2% (±2.5%)	— / —
naive-bayes	21	✅ 1252 ms (136 iters)	✅ 1248 ms (137 iters)	≈ -0.3% (±32.7%)	— / —
naive-bayes	25	✅ 1008 ms (170 iters)	✅ 1023 ms (167 iters)	≈ +1.5% (±31.7%)	— / —
reactors	21	✅ 16312 ms (15 iters)	✅ 16357 ms (15 iters)	≈ +0.3% (±8.8%)	— / —
reactors	25	✅ 18416 ms (15 iters)	✅ 18780 ms (15 iters)	≈ +2% (±3.6%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	2 / ✅	1891 / 2004	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	1 / 1	2305 / 2283	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	4 / 2	8183 / 8674	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	✅ / ✅	8087 / 8641	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	2 / 2	1270 / 1278	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	3 / 3	1282 / 1275	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	1 / 3	2966 / 3007	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	2 / ✅	2992 / 2972	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	3 / 6	3491 / 3501	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	1 / 5	3488 / 3493	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	2 / ✅	1711 / 1786	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / ✅	1819 / 1920	✅ / ✅	✅ / ✅

dd-octo-sts · 2026-07-19T21:44:20Z

Benchmark Results (commit `1118f62`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125554643 Commit: 1118f62831a4384bdf0283ef01a626c5bdc48af5

⚠️ Significant outliers

🟢 fj-kmeans (JDK 21): runtime -3.9% (2808→2698 ms)
🟢 future-genetic (JDK 25): runtime -4.2% (2088→2001 ms)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10294 ms (21 iters)	✅ 10251 ms (21 iters)	≈ -0.4% (±11.4%)	— / —
akka-uct	25	✅ 8933 ms (24 iters)	✅ 8835 ms (24 iters)	≈ -1.1% (±10%)	— / —
finagle-chirper	21	✅ 6016 ms (33 iters)	✅ 6034 ms (33 iters)	≈ +0.3% (±25.3%)	⚠️ W:3 / ⚠️ W:3
finagle-chirper	25	✅ 5462 ms (36 iters)	✅ 5452 ms (36 iters)	≈ -0.2% (±24.6%)	⚠️ W:3 / ⚠️ W:3
fj-kmeans	21	✅ 2808 ms (66 iters)	✅ 2698 ms (70 iters)	🟢 -3.9%	— / —
fj-kmeans	25	✅ 2812 ms (66 iters)	✅ 2813 ms (66 iters)	≈ +0% (±2.6%)	— / —
future-genetic	21	✅ 2067 ms (90 iters)	✅ 2083 ms (90 iters)	≈ +0.8% (±2.7%)	— / —
future-genetic	25	✅ 2088 ms (89 iters)	✅ 2001 ms (93 iters)	🟢 -4.2%	— / —
naive-bayes	21	✅ 1239 ms (138 iters)	✅ 1231 ms (138 iters)	≈ -0.6% (±32.7%)	— / —
naive-bayes	25	✅ 1019 ms (168 iters)	✅ 1011 ms (169 iters)	≈ -0.8% (±32.1%)	— / —
reactors	21	✅ 16149 ms (15 iters)	✅ 16215 ms (15 iters)	≈ +0.4% (±8.4%)	— / —
reactors	25	✅ 18598 ms (15 iters)	✅ 18345 ms (15 iters)	≈ -1.4% (±5.1%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	2 / 2	1978 / 1973	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	2 / ✅	2287 / 2449	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	2 / 2	8978 / 8724	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	✅ / ✅	8633 / 8297	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	2 / 1	1257 / 1281	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	1 / 4	1280 / 1268	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	✅ / 3	2909 / 2923	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	2 / 5	2847 / 2887	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	7 / 4	3492 / 3493	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	4 / 2	3463 / 3473	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	✅ / 1	1761 / 1721	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / ✅	1916 / 1880	✅ / ✅	✅ / ✅

dd-octo-sts · 2026-07-20T08:43:08Z

Benchmark Results (commit `40dbe8e`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125596529 Commit: 40dbe8e833888192b6026558590bce1cf0ad1c9f

⚠️ Significant outliers

🟢 fj-kmeans (JDK 21): runtime -2.7% (2823→2748 ms)
🔴 future-genetic (JDK 21): runtime +4.1% (2041→2125 ms)
🔴 future-genetic (JDK 25): runtime +5.8% (1994→2110 ms)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10340 ms (21 iters)	✅ 10312 ms (21 iters)	≈ -0.3% (±11.6%)	— / —
akka-uct	25	✅ 8871 ms (24 iters)	✅ 8849 ms (24 iters)	≈ -0.2% (±10.1%)	— / —
finagle-chirper	21	✅ 6017 ms (33 iters)	✅ 6015 ms (33 iters)	≈ -0% (±25%)	⚠️ W:3 / ⚠️ W:4
finagle-chirper	25	✅ 5470 ms (36 iters)	✅ 5509 ms (36 iters)	≈ +0.7% (±24.2%)	⚠️ W:4 / ⚠️ W:3
fj-kmeans	21	✅ 2823 ms (66 iters)	✅ 2748 ms (68 iters)	🟢 -2.7%	— / —
fj-kmeans	25	✅ 2856 ms (66 iters)	✅ 2847 ms (66 iters)	≈ -0.3% (±2.6%)	— / —
future-genetic	21	✅ 2041 ms (90 iters)	✅ 2125 ms (88 iters)	🔴 +4.1%	— / —
future-genetic	25	✅ 1994 ms (93 iters)	✅ 2110 ms (88 iters)	🔴 +5.8%	— / —
naive-bayes	21	✅ 1247 ms (137 iters)	✅ 1259 ms (135 iters)	≈ +1% (±33.5%)	— / —
naive-bayes	25	✅ 1027 ms (167 iters)	✅ 1018 ms (168 iters)	≈ -0.9% (±31.5%)	— / —
reactors	21	✅ 16583 ms (15 iters)	✅ 16798 ms (15 iters)	≈ +1.3% (±7.5%)	— / —
reactors	25	✅ 18582 ms (15 iters)	✅ 18610 ms (15 iters)	≈ +0.2% (±5.1%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / 6	1978 / 1998	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	✅ / 1	2344 / 2271	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	2 / 2	8863 / 8312	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	1 / ✅	8368 / 8738	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	7 / 1	1284 / 1242	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	1 / 4	1302 / 1289	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	1 / 1	2979 / 2980	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	✅ / ✅	2847 / 2862	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	4 / 5	3520 / 3534	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	3 / 3	3523 / 3509	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	2 / 2	1682 / 1809	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	2 / ✅	1806 / 1871	✅ / ✅	✅ / ✅

Copilot

Pull request overview

Extends wall-clock “owned-block” signal suppression to unfiltered (explicit filter=) wall recordings when wallprecheck=true, by introducing a thread registry keyed by native TID and integrating it into both ASGCT and JVMTI wall-clock sampling paths.

Changes:

Added unfiltered wall thread registry support (native TID indexing, lifecycle generations, recording epochs) and wired it into profiler lifecycle + wall-clock precheck logic.
Added a bounded candidate-selection/backfill mechanism for precheck to avoid reverting to O(N) registry work per wall tick under heavy suppression.
Added Java integration tests, C++ unit tests, and a JMH benchmark to validate behavior and measure overhead.

Reviewed changes

Copilot reviewed 22 out of 22 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckTest.java	New integration coverage for suppression behavior in explicit-empty-filter wall recordings.
ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckRestartTest.java	Verifies registry activation does not leak across recording restarts and handles stopped gaps safely.
ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/JvmtiBasedUnfilteredWallPrecheckTest.java	Ensures the unfiltered path works when wall sampling delegates stacks via JVMTI.
ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/J9WallClockPrecheckCapabilityTest.java	Confirms J9 wall engine capability gating prevents activation of unfiltered tracking.
ddprof-test/src/test/java/com/datadoghq/profiler/AbstractProfilerTest.java	Adds `beforeProfilerStart()` hook to allow test setup before profiler thread callbacks are enabled.
ddprof-stresstest/src/jmh/java/com/datadoghq/profiler/WallClockPrecheckBenchmarkHooks.java	Exposes owned-block hooks to benchmarks without widening core API surface.
ddprof-stresstest/src/jmh/java/com/datadoghq/profiler/stresstest/scenarios/throughput/WallClockPrecheckOverheadBenchmark.java	Adds throughput benchmark comparing `wallprecheck=false/true` as owned-block population grows.
ddprof-lib/src/test/cpp/wallprecheck_args_ut.cpp	Adds capability tests and verifies explicit-empty vs omitted `filter` parsing behavior.
ddprof-lib/src/test/cpp/wallClockCandidateSelector_ut.cpp	Unit-tests the new bounded candidate selection logic.
ddprof-lib/src/test/cpp/threadFilter_ut.cpp	Expands tests for registry/epoch/lifecycle behavior and adjusts TID usage in recovery test.
ddprof-lib/src/main/cpp/wallClockCandidateSelector.h	Adds reusable “randomized prefix without replacement” candidate selection with stats.
ddprof-lib/src/main/cpp/wallClock.h	Integrates candidate selector and adds bounded-visit backfill path to the wall timer loop.
ddprof-lib/src/main/cpp/wallClock.cpp	Updates precheck suppression to validate registry identity + context transitions; supports lazy registry lookups.
ddprof-lib/src/main/cpp/threadFilter.h	Introduces registry state (TID index, epochs, lifecycle generation) and APIs for unfiltered tracking.
ddprof-lib/src/main/cpp/threadFilter.cpp	Implements lock-free lookups + mutex-serialized writers for TID indexing, epoch refresh, and retirement.
ddprof-lib/src/main/cpp/profiler.h	Declares bootstrap of existing Java threads for registry population.
ddprof-lib/src/main/cpp/profiler.cpp	Boots existing Java threads into registry when unfiltered tracking is active; deactivates registry on stop/failure.
ddprof-lib/src/main/cpp/jvmThread.h	Adds capability check for cross-thread native TID lookup support.
ddprof-lib/src/main/cpp/jvmThread.cpp	Implements native TID lookup support predicate.
ddprof-lib/src/main/cpp/javaApi.cpp	Ensures TLS slot binding is validated/refreshed before using owned-block and filter APIs.
ddprof-lib/src/main/cpp/engine.h	Adds wall-engine capability hook for unfiltered precheck support.
ddprof-lib/src/main/cpp/counters.h	Adds counters for registry bootstrap and bounded-lookup/backfill diagnostics.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

dd-octo-sts · 2026-07-21T07:47:51Z

Benchmark Results (commit `d82291f`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125875202 Commit: d82291ff62852b63091350a05ebf26283fa39029

✅ Within expected boundaries

No significant runtime deltas (all within run-to-run noise) and no internal-counter outliers.

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10141 ms (21 iters)	✅ 10278 ms (21 iters)	≈ +1.4% (±11.9%)	— / —
akka-uct	25	✅ 8800 ms (24 iters)	✅ 8939 ms (24 iters)	≈ +1.6% (±9.7%)	— / —
finagle-chirper	21	✅ 6003 ms (33 iters)	✅ 6060 ms (33 iters)	≈ +0.9% (±25.4%)	⚠️ W:3 / ⚠️ W:3
finagle-chirper	25	✅ 5463 ms (36 iters)	✅ 5482 ms (36 iters)	≈ +0.3% (±24.1%)	⚠️ W:3 / ⚠️ W:3
fj-kmeans	21	✅ 2780 ms (68 iters)	✅ 2771 ms (68 iters)	≈ -0.3% (±2.7%)	— / —
fj-kmeans	25	✅ 2752 ms (68 iters)	✅ 2824 ms (66 iters)	≈ +2.6% (±2.7%)	— / —
future-genetic	21	✅ 2082 ms (90 iters)	✅ 2035 ms (91 iters)	≈ -2.3% (±2.6%)	— / —
future-genetic	25	✅ 2101 ms (88 iters)	✅ 2055 ms (90 iters)	≈ -2.2% (±2.6%)	— / —
naive-bayes	21	✅ 1299 ms (132 iters)	✅ 1232 ms (138 iters)	≈ -5.2% (±31.7%)	— / —
naive-bayes	25	✅ 1011 ms (169 iters)	✅ 1013 ms (169 iters)	≈ +0.2% (±31.4%)	— / —
reactors	21	✅ 16511 ms (15 iters)	✅ 16445 ms (15 iters)	≈ -0.4% (±9.8%)	— / —
reactors	25	✅ 18516 ms (15 iters)	✅ 18146 ms (15 iters)	≈ -2% (±6.2%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	2 / 2	1925 / 1914	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	2 / 3	2117 / 2331	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	4 / 3	8401 / 8842	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	1 / 1	8557 / 8073	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	2 / 3	1243 / 1272	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	✅ / 1	1265 / 1283	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	3 / 1	3054 / 3036	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	✅ / 1	2890 / 2867	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	4 / 3	3522 / 3464	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	4 / 5	3452 / 3463	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	✅ / 2	1679 / 1552	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / ✅	1933 / 1805	✅ / ✅	✅ / ✅

dd-octo-sts · 2026-07-21T08:27:57Z

Benchmark Results (commit `ec76f58`)

Pipeline: https://gitlab.ddbuild.io/DataDog/apm-reliability/benchmarking-platform/-/pipelines/125883187 Commit: ec76f5829d243f516dee70833f3dfbe7a2b9eaa3

⚠️ Significant outliers

🟢 fj-kmeans (JDK 21): runtime -4.1% (2839→2724 ms)
🔴 future-genetic (JDK 21): runtime +3% (2066→2127 ms)
🔴 future-genetic (JDK 25): runtime +5.8% (2006→2122 ms)

Runtime details (per benchmark × JDK)

Benchmark	JDK	Latest	Dev	Δ (dev vs latest)	Issues L/D
akka-uct	21	✅ 10350 ms (21 iters)	✅ 10305 ms (21 iters)	≈ -0.4% (±11.3%)	— / —
akka-uct	25	✅ 8864 ms (24 iters)	✅ 8976 ms (24 iters)	≈ +1.3% (±10.4%)	— / —
finagle-chirper	25	✅ 5472 ms (36 iters)	✅ 5418 ms (36 iters)	≈ -1% (±24.3%)	⚠️ W:3 / ⚠️ W:3
fj-kmeans	21	✅ 2839 ms (66 iters)	✅ 2724 ms (68 iters)	🟢 -4.1%	— / —
fj-kmeans	25	✅ 2851 ms (66 iters)	✅ 2836 ms (66 iters)	≈ -0.5% (±2.6%)	— / —
future-genetic	21	✅ 2066 ms (89 iters)	✅ 2127 ms (87 iters)	🔴 +3%	— / —
future-genetic	25	✅ 2006 ms (92 iters)	✅ 2122 ms (87 iters)	🔴 +5.8%	— / —
naive-bayes	21	✅ 1277 ms (134 iters)	✅ 1289 ms (133 iters)	≈ +0.9% (±32.4%)	— / —
naive-bayes	25	✅ 1021 ms (167 iters)	✅ 1023 ms (168 iters)	≈ +0.2% (±31.6%)	— / —
reactors	21	✅ 15903 ms (15 iters)	✅ 16452 ms (15 iters)	≈ +3.5% (±8.8%)	— / —
reactors	25	✅ 18032 ms (15 iters)	✅ 18628 ms (15 iters)	≈ +3.3% (±4.7%)	— / —

Internal counter details (ddprof)

ddprof internal counters, latest / dev (✅ = 0, · = unavailable):

Benchmark	JDK	Dropped rec	Dropped jvmti	Dropped trace	Skipped WC	AGCT fail	Unwind fail
akka-uct	21	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅	✅ / ✅
akka-uct	25	✅ / ✅	✅ / ✅	1 / 3	2089 / 2428	✅ / ✅	✅ / ✅
finagle-chirper	21	✅ / ✅	✅ / ✅	7 / 2	8520 / 8487	✅ / ✅	✅ / ✅
finagle-chirper	25	✅ / ✅	✅ / ✅	4 / 2	8382 / 8319	✅ / ✅	✅ / ✅
fj-kmeans	21	✅ / ✅	✅ / ✅	4 / 4	1278 / 1277	✅ / ✅	✅ / ✅
fj-kmeans	25	✅ / ✅	✅ / ✅	4 / ✅	1290 / 1289	✅ / ✅	✅ / ✅
future-genetic	21	✅ / ✅	✅ / ✅	3 / 2	2953 / 3032	✅ / ✅	✅ / ✅
future-genetic	25	✅ / ✅	✅ / ✅	2 / 2	2846 / 2856	✅ / ✅	✅ / ✅
naive-bayes	21	✅ / ✅	✅ / ✅	3 / 3	3534 / 3561	✅ / ✅	✅ / ✅
naive-bayes	25	✅ / ✅	✅ / ✅	1 / 3	3480 / 3510	✅ / ✅	✅ / ✅
reactors	21	✅ / ✅	✅ / ✅	1 / ✅	1614 / 1718	✅ / ✅	✅ / ✅
reactors	25	✅ / ✅	✅ / ✅	✅ / 3	1962 / 1876	✅ / ✅	✅ / ✅

chatgpt-codex-connector

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: a68d3f22c6

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

Open a pull request for review
Mark a draft as ready
Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

jbachorik

🗿 🤖 🔴

Sphinx Review found 2 critical/high severity finding(s) that must be addressed.

jbachorik · 2026-08-18T15:01:42Z


-    if (_thread_filter.enabled()) {
-      _thread_filter.unregisterThread(slot_id);
+    if (slot_id >= 0) {


🗿 🤖 🔴

[Sphinx Review — MEDIUM] onThreadEnd() now unconditionally calls _thread_filter.unregisterThread()/unregisterThreadByTid() (both mutex-guarded) for every JVMTI ThreadEnd event whenever any profiling engine is active, instead of being gated behind the thread-filter registry's active/enabled state as before.

Suggestion: Gate the else-branch (and ideally both branches) behind _thread_filter.registryActive() (or a cheaper lock-free check) so thread teardown for profiling sessions that never use the registry does not pay for a mutex acquisition.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

# Conflicts: # ddprof-lib/src/main/cpp/javaApi.cpp

jbachorik

Could you, please, also take a look if it makes sense to add new adversaries in the chaos tests, or some fuzzing tests?

…-DEBUG builds - flightRecorder.cpp: restore "<unloaded>" stale-jmethodID label (was reverted to "jvmtiError"), undoing #744 - JMethodIDInvalidationStressTest: restore assertUnloadedFrameLabel() regression guard + imports + gating assumeTrue - UnfilteredWallPrecheckFallbackTest: self-skip via Assumptions.assumeTrue when the DEBUG-only force-wall-start-failure hook is not armed, so the test no longer fails spuriously in release builds - add BaseWallClock::isForceStartFailureForTest() getter + JNI accessor isForceWallStartFailureArmedForTest0 (returns JNI_FALSE outside DEBUG)

…ockBlockTracker new class

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch 3 times, most recently from 3902a14 to f302dd5 Compare July 19, 2026 12:00

kaahos changed the title ~~feat(wall): add configurable wall thread scope~~ feat(wall): support signal suppression for unfiltered threads Jul 19, 2026

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch 2 times, most recently from 0ad425c to fb1c44d Compare July 19, 2026 18:43

feat(wall): track all threads for unfiltered wall-clock precheck

1118f62

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch from fb1c44d to 1118f62 Compare July 19, 2026 21:16

Merge branch 'main' into paul.fournillon/wallclock-all-threads

40dbe8e

Merge branch 'main' into paul.fournillon/wallclock-all-threads

d82291f

Copilot AI review requested due to automatic review settings July 21, 2026 07:17

Copilot started reviewing on behalf of kaahos July 21, 2026 07:18 View session

Copilot AI reviewed Jul 21, 2026

View reviewed changes

Comment thread ddprof-lib/src/main/cpp/wallClockCandidateSelector.h

Comment thread ddprof-lib/src/test/cpp/wallClockCandidateSelector_ut.cpp

Comment thread ddprof-test/src/test/java/com/datadoghq/profiler/wallclock/UnfilteredWallPrecheckTest.java

fix: apply review suggestions

ec76f58

Merge branch 'main' into paul.fournillon/wallclock-all-threads

52def55

DataDog deleted a comment from dd-octo-sts Bot Jul 21, 2026

kaahos marked this pull request as ready for review August 17, 2026 14:03

kaahos requested a review from a team as a code owner August 17, 2026 14:03

chatgpt-codex-connector Bot reviewed Aug 17, 2026

View reviewed changes

Comment thread ddprof-lib/src/main/cpp/threadFilter.cpp Outdated

jbachorik requested changes Aug 18, 2026

View reviewed changes

jbachorik added the sphinx:critical Sphinx: critical — human review required label Aug 18, 2026

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch from af36f26 to 2a142a6 Compare August 18, 2026 18:41

fix: address some review comments

391fdd2

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch from 2a142a6 to 391fdd2 Compare August 18, 2026 18:58

kaahos requested a review from jbachorik August 18, 2026 19:03

kaahos and others added 5 commits August 19, 2026 10:05

fix: address review comments

d6f5b1a

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

fix: avoid CAS on context-window enter/exit hot path

4d2c505

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Merge branch 'main' into paul.fournillon/wallclock-all-threads

8ef675e

# Conflicts: # ddprof-lib/src/main/cpp/javaApi.cpp

fix: fix musl bug

172e453

Merge branch 'main' into paul.fournillon/wallclock-all-threads

1b94815

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch from 5c765fa to 1b94815 Compare August 20, 2026 13:01

jbachorik requested changes Aug 20, 2026

View reviewed changes

kaahos requested a review from jbachorik August 21, 2026 14:03

fix: address some review comments

26ae49b

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch from e0ec41e to 26ae49b Compare August 21, 2026 14:16

jbachorik added test:asan Run CI tests with AddressSanitizer configuration test:tsan Run CI tests with ThreadSanitizer configuration test:fuzz labels Aug 31, 2026

kaahos added 2 commits September 28, 2026 17:33

fix: extract wallclock suppresion stuff from ThreadFilter into wallCl…

772e5aa

…ockBlockTracker new class

Merge branch 'main' into paul.fournillon/wallclock-all-threads

cd2ad5b

kaahos force-pushed the paul.fournillon/wallclock-all-threads branch from b331762 to cd2ad5b Compare September 28, 2026 16:25

kaahos added 4 commits September 28, 2026 22:44

fix: address glibc issue with random

c8701f7

fix: fix fuzz test

30f63dc

fix: fix mutex performance regressions

37af845

Merge branch 'main' into paul.fournillon/wallclock-all-threads

016e3f9

Conversation

kaahos commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

dd-octo-sts Bot commented Jul 16, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

CI Test Results

Status Overview

❌ Failing tests

Failed Jobs

Uh oh!

dd-octo-sts Bot commented Jul 19, 2026

Benchmark Results (commit fb1c44d)

⚠️ Significant outliers

Uh oh!

dd-octo-sts Bot commented Jul 19, 2026

Benchmark Results (commit 1118f62)

⚠️ Significant outliers

Uh oh!

dd-octo-sts Bot commented Jul 20, 2026

Benchmark Results (commit 40dbe8e)

⚠️ Significant outliers

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

dd-octo-sts Bot commented Jul 21, 2026

Benchmark Results (commit d82291f)

✅ Within expected boundaries

Uh oh!

dd-octo-sts Bot commented Jul 21, 2026

Benchmark Results (commit ec76f58)

⚠️ Significant outliers

Uh oh!

chatgpt-codex-connector Bot left a comment

Choose a reason for hiding this comment

💡 Codex Review

Uh oh!

Uh oh!

jbachorik left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

jbachorik Aug 18, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

jbachorik left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

This branch has not been deployed

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

kaahos commented Jul 16, 2026 •

edited

Loading

dd-octo-sts Bot commented Jul 16, 2026 •

edited

Loading

Benchmark Results (commit `fb1c44d`)

Benchmark Results (commit `1118f62`)

Benchmark Results (commit `40dbe8e`)

Benchmark Results (commit `d82291f`)

Benchmark Results (commit `ec76f58`)