benchmark: add benchmark groups

Add the `byGroup` option to have parameter grouping.
The environment variable `NODE_RUN_BENCHMARK_GROUPS` allows to benchmark
only certain groups: `NODE_RUN_BENCHMARK_GROUPS=groupA,groupB`.

Fixes: nodejs#26425

benchmark/common.js

@@ -24,16 +24,34 @@ class Benchmark {
 
     // Parse job-specific configuration from the command line arguments
     const argv = process.argv.slice(2);
-    const parsed_args = this._parseArgs(argv, configs, options);
-    this.options = parsed_args.cli;
-    this.extra_options = parsed_args.extra;
+
+    // The configuration list as a queue of jobs
+    this.queue = [];
+
+    if (options.byGroup) {
+      const groups = process.env.hasOwnProperty('NODE_RUN_BENCHMARK_GROUPS') ?
+        process.env.NODE_RUN_BENCHMARK_GROUPS.split(',') :
+        Object.keys(configs);
+
+      for (const key of groups) {
+        const config = configs[key];
+        config.group = key;
+        const parsed_args = this._parseArgs(argv, config, options);
+        this.options = parsed_args.cli;
+        this.extra_options = parsed_args.extra;
+        this.queue = this.queue.concat(this._queue(this.options));
+      }
+    } else {
+      const parsed_args = this._parseArgs(argv, configs, options);
+      this.options = parsed_args.cli;
+      this.extra_options = parsed_args.extra;
+      this.queue = this._queue(this.options);
+    }
+
     if (options.flags) {
       this.flags = this.flags.concat(options.flags);
     }
 
-    // The configuration list as a queue of jobs
-    this.queue = this._queue(this.options);
-
     // The configuration of the current job, head of the queue
     this.config = this.queue[0];
 

doc/guides/writing-and-running-benchmarks.md

@@ -444,8 +444,24 @@ The arguments of `createBenchmark` are:
   possible combinations of these parameters, unless specified otherwise.
   Each configuration is a property with an array of possible values.
   The configuration values can only be strings or numbers.
-* `options` {Object} The benchmark options. At the moment only the `flags`
-  option for specifying command line flags is supported.
+* `options` {Object} The benchmark options:
+  * `flags` option for specifying command line flags is supported
+  * `byGroup` option for processing `configs` by groups:
+
+```js
+const bench = common.createBenchmark(main, {
+  groupA: {
+    source: ['array'],
+    len: [10, 2048],
+    n: [50],
+  },
+  groupB: {
+    source: ['buffer', 'string'],
+    len: [2048],
+    n: [50, 2048],
+  }
+}, { byGroup: true });
+```
 
 `createBenchmark` returns a `bench` object, which is used for timing
 the runtime of the benchmark. Run `bench.start()` after the initialization