ci: remove "max-workers" and test with our gradle defaults (#15307)

If our defaults need improvement, let's improve them to make tests run
faster. We want to take advantage of the hardware.

Tests use all runner cores with defaults and some macos stability hacks 
were added to speed up the worst-case builds.

Author: rmuir

.github/workflows/run-checks-all.yml

@@ -58,7 +58,7 @@ jobs:
           echo "lucene.tool.ast-grep=ast-grep" >> build-options.local.properties
 
       - name: Run gradle check (without tests)
-        run: ./gradlew check -x test "-Ptask.times=true" --max-workers 2
+        run: ./gradlew check -x test "-Ptask.times=true"
 
 
   # This runs all tests without any other validation checks.
@@ -87,8 +87,20 @@ jobs:
       - name: Configure tools
         uses: ./.github/actions/prepare-for-build
 
+      - name: Speedup MacOS runner
+        if: ${{ runner.os == 'macOS' }}
+        run: |
+          mkdir /tmp/tmpfs
+          sudo mount_tmpfs -o noowners -s 1g /tmp/tmpfs
+          sudo sysctl debug.lowpri_throttle_enabled=0
+          echo "tests.workDir=/tmp/tmpfs/lucene" >> build-options.local.properties
+
       - name: Run gradle tests
-        run: ./gradlew test "-Ptask.times=true" "-Pvalidation.errorprone=false" --max-workers 2
+        run: ./gradlew test "-Ptask.times=true" "-Pvalidation.errorprone=false"
+        env:
+          # Set to the defaults to override the "CI"-based logic that would enable C2
+          # we can't afford C2 on github runners.
+          TEST_JVM_ARGS: "-XX:TieredStopAtLevel=1 -XX:+UseParallelGC -XX:ActiveProcessorCount=1"
 
       - name: List automatically-initialized gradle.properties
         run: cat gradle.properties

build-tools/build-infra/src/main/java/org/apache/lucene/gradle/GradlePropertiesGenerator.java

@@ -54,10 +54,10 @@ public void run(Path source, Path destination) throws IOException {
     }
 
     // Approximate a common-sense default for running gradle/tests with parallel
-    // workers: half the count of available cpus but not more than 12.
+    // workers: the count of available cpus but not more than 12.
     var cpus = Runtime.getRuntime().availableProcessors();
-    var maxWorkers = (int) Math.max(1d, Math.min(cpus * 0.5d, 12));
-    var testsJvms = (int) Math.max(1d, Math.min(cpus * 0.5d, 12));
+    var maxWorkers = Math.min(cpus, 12);
+    var testsJvms = Math.min(cpus, 12);
 
     var replacements = Map.of("@MAX_WORKERS@", maxWorkers, "@TEST_JVMS@", testsJvms);
 

build-tools/build-infra/src/main/java/org/apache/lucene/gradle/plugins/java/TestsAndRandomizationPlugin.java

@@ -186,9 +186,7 @@ public void apply(Project project) {
                 .getProviders()
                 .provider(
                     () -> {
-                      return ((int)
-                          Math.max(
-                              1, Math.min(Runtime.getRuntime().availableProcessors() / 2.0, 4.0)));
+                      return Math.min(12, Runtime.getRuntime().availableProcessors());
                     }));
 
     // GITHUB#13986: Allow easier configuration of the Panama Vectorization provider with newer Java

gradle/template.gradle.properties

@@ -16,15 +16,15 @@
 ###############
 #
 # Gradle build can run tasks in parallel but by default it consumes all CPU cores which
-# is too optimistic a default for Lucene tests. You can disable the parallelism
+# may be too optimistic a default for Lucene tests. You can disable the parallelism
 # entirely or assign it a 'low' priority with these properties:
 #
 # org.gradle.parallel=[true, false]
 # org.gradle.priority=[normal, low]
 #
 # The default level of parallelism is computed based on the number of cores on
 # your machine (on the first run of gradle build). By default these are fairly conservative
-# settings (half the number of cores for workers, for example):
+# settings (the number of cores for workers up to a limit of 12, for example):
 #
 # org.gradle.workers.max=[X]
 # tests.jvms=[N <= X]