[GitHub] [kafka] chia7712 commented on a change in pull request #9129: MINOR: Update jmh to 1.27 for async profiler support

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chia7712 commented on a change in pull request #9129:
URL: https://github.com/apache/kafka/pull/9129#discussion_r539901142



##########
File path: jmh-benchmarks/README.md
##########
@@ -1,10 +1,69 @@
-### JMH-Benchmark module
+### JMH-Benchmarks module
 
 This module contains benchmarks written using [JMH](https://openjdk.java.net/projects/code-tools/jmh/) from OpenJDK.
 Writing correct micro-benchmarks in Java (or another JVM language) is difficult and there are many non-obvious pitfalls (many
 due to compiler optimizations). JMH is a framework for running and analyzing benchmarks (micro or macro) written in Java (or
 another JVM language).
 
+### Running benchmarks
+
+If you want to set specific JMH flags or only run certain benchmarks, passing arguments via
+gradle tasks is cumbersome. These are simplified by the provided `jmh.sh` script.
+
+The default behavior is to run all benchmarks:
+
+    ./jmh-benchmarks/jmh.sh
+    
+Pass a pattern or name after the command to select the benchmarks:
+
+    ./jmh-benchmarks/jmh.sh LRUCacheBenchmark
+
+Check which benchmarks that match the provided pattern:
+
+    ./jmh-benchmarks/jmh.sh -l LRUCacheBenchmark
+
+Run a specific test and override the number of forks, iterations and warm-up iteration to `2`:
+
+    ./jmh-benchmarks/jmh.sh -f 2 -i 2 -wi 2 LRUCacheBenchmark
+
+Run a specific test with async and GC profilers on Linux and flame graph output:
+
+    ./jmh-benchmarks/jmh.sh -prof gc -prof 'async:libPath=/path/to/async-profiler.so;output=flamegraph' LRUCacheBenchmark
+
+The following sections cover async profiler and GC profilers in more detail.
+
+### Using JMH with async profiler
+
+It's good practice to check profiler output for microbenchmarks in order to verify that they are valid.
+JMH includes [async-profiler](https://github.com/jvm-profiling-tools/async-profiler) integration that makes this easy:
+
+    ./jmh-benchmarks/jmh.sh -prof async:libPath=/path/to/async-profiler.so

Review comment:
       The file name of async-profiler is ```libasyncProfiler.so```. Should we follow the naming in this example?




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