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Baraa-HasheeshBaraa-Hasheesh
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An option to select TLAB based AllocTracer engine with JDK 11+ (async-profiler#1671)
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‎docs/ProfilerOptions.md‎

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@@ -32,6 +32,7 @@ The below options are `action`s for async-profiler and common for both `asprof`
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| `-e --event EVENT` | `event=EVENT` | The profiling event: `cpu`, `alloc`, `nativemem`, `lock`, `cache-misses` etc. Use `list` to see the complete list of available events.<br>Please refer to [Profiling Modes](ProfilingModes.md) for additional information. |
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| `-i --interval N` | `interval=N` | Interval has different meaning depending on the event. For CPU profiling, it's CPU time in nanoseconds. In wall clock mode, it's wall clock time. For Java method profiling or native function profiling, it's number of calls. For PMU profiling, it's number of events. Time intervals may be followed by `s` for seconds, `ms` for milliseconds, `us` for microseconds or `ns` for nanoseconds.<br>Example: `asprof -e cpu -i 5ms 8983` |
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| `--alloc N` | `alloc=N` | Allocation profiling interval in bytes or in other units, if N is followed by `k` (kilobytes), `m` (megabytes), or `g` (gigabytes). |
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| `--tlab` | `tlab` | Use TLAB events for allocation profiling |
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| `--live` | `live` | Retain allocation samples with live objects only (object that have not been collected by the end of profiling session). Useful for finding Java heap memory leaks. |
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| `--nativemem N` | `nativemem=N` | Native memory allocation profiling. N, if specified is the interval in bytes or in other units, if N is followed by `k` (kilobytes), `m` (megabytes), or `g` (gigabytes). Default N is 0. |
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| `--nofree` | `nofree` | Will not record free calls in native memory allocation profiling. This is relevant when tracking memory leaks is not important and there are lots of free calls. |

‎src/arguments.cpp‎

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@@ -50,6 +50,7 @@ const size_t EXTRA_BUF_SIZE = 512;
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// version - display the agent version
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// event=EVENT - which event to trace (cpu, wall, cache-misses, etc.)
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// alloc[=BYTES] - profile allocations with BYTES interval
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// tlab - use TLAB events for allocation profiling
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// live - build allocation profile from live objects only
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// nativemem[=BYTES] - profile native allocations with BYTES interval
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// nofree - do not collect free calls in native allocation profiling
@@ -246,6 +247,9 @@ Error Arguments::parse(const char* args) {
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CASE("alloc")
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_alloc = value == NULL ? 0 : parseUnits(value, BYTES);
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CASE("tlab")
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_tlab = true;
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CASE("nativemem")
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_nativemem = value == NULL ? 0 : parseUnits(value, BYTES);
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‎src/arguments.h‎

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@@ -200,6 +200,7 @@ class Arguments {
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bool _threads;
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bool _sched;
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bool _record_cpu;
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bool _tlab;
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bool _live;
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bool _nofree;
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bool _nobatch;
@@ -261,6 +262,7 @@ class Arguments {
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_threads(false),
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_sched(false),
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_record_cpu(false),
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_tlab(false),
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_live(false),
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_nofree(false),
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_nobatch(false),

‎src/main/main.cpp‎

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@@ -69,6 +69,7 @@ static const char USAGE_STRING[] =
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"\n"
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" --loop time run profiler in a loop\n"
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" --alloc bytes allocation profiling interval in bytes\n"
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" --tlab use TLAB events for allocation profiling\n"
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" --live build allocation profile from live objects only\n"
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" --nativemem bytes native allocation profiling interval in bytes\n"
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" --nofree do not collect free calls in native allocation profiling\n"
@@ -501,7 +502,8 @@ int main(int argc, const char** argv) {
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format << "," << (arg.str() + 2) << "=" << args.next();
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} else if (arg == "--reverse" || arg == "--inverted" || arg == "--samples" || arg == "--total" ||
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arg == "--sched" || arg == "--live" || arg == "--nofree" || arg == "--record-cpu") {
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arg == "--sched" || arg == "--live" || arg == "--nofree" || arg == "--record-cpu" ||
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arg == "--tlab") {
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format << "," << (arg.str() + 2);
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} else if (arg == "--alloc" || arg == "--nativemem" || arg == "--nativelock" || arg == "--lock" ||

‎src/profiler.cpp‎

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@@ -991,8 +991,8 @@ Engine* Profiler::selectEngine(Arguments& args) {
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}
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}
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Engine* Profiler::selectAllocEngine(long alloc_interval, bool live) {
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if (VM::addSampleObjectsCapability()) {
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Engine* Profiler::selectAllocEngine(bool tlab) {
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if (!tlab && VM::addSampleObjectsCapability()) {
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return &object_sampler;
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} else if (VM::isOpenJ9()) {
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return &j9_object_sampler;
@@ -1204,7 +1204,7 @@ Error Profiler::start(Arguments& args, bool reset) {
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}
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if (_event_mask & EM_ALLOC) {
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_alloc_engine = selectAllocEngine(args._alloc, args._live);
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_alloc_engine = selectAllocEngine(args._tlab);
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error = _alloc_engine->start(args);
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if (error) {
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goto error2;

‎src/profiler.h‎

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@@ -123,7 +123,7 @@ class Profiler {
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void updateNativeThreadNames();
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void mangle(const char* name, char* buf, size_t size);
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Engine* selectEngine(Arguments& args);
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Engine* selectAllocEngine(long alloc_interval, bool live);
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Engine* selectAllocEngine(bool tlab);
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Engine* activeEngine();
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Error checkJvmCapabilities();
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‎test/test/alloc/AllocTests.java‎

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@@ -5,6 +5,8 @@
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package test.alloc;
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import jdk.jfr.consumer.RecordedEvent;
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import jdk.jfr.consumer.RecordingFile;
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import one.jfr.JfrReader;
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import one.jfr.StackTrace;
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import one.jfr.event.AllocationSample;
@@ -61,6 +63,25 @@ public void humongous(TestProcess p) throws Exception {
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assert out.contains("G1CollectedHeap::humongous_obj_allocate");
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}
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@Test(mainClass = MapReaderOpt.class)
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public void tlabAllocSampler(TestProcess p) throws Exception {
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p.profile("-e alloc --tlab -d 3 -f %profile.jfr");
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boolean tlabEvent = false;
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try (RecordingFile recordingFile = new RecordingFile(p.getFile("%profile").toPath())) {
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while (recordingFile.hasMoreEvents()) {
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RecordedEvent event = recordingFile.readEvent();
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String eventName = event.getEventType().getName();
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if (eventName != null && eventName.equals("jdk.ObjectAllocationOutsideTLAB")) {
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tlabEvent = true;
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break;
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}
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}
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}
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assert tlabEvent : "No jdk.ObjectAllocationOutsideTLAB event was found";
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}
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@Test(mainClass = MapReaderOpt.class, jvmVer = {11, Integer.MAX_VALUE})
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public void objectSamplerWtihDifferentAsprofs(TestProcess p) throws Exception {
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Output out = p.profile("-e alloc -d 3 -o collapsed");

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