Benchmarking Build Performance of OpenJDK

Documentation: Updating OpenJDK for Android Platform Builds

1. Build openjdk17 locally

PATH/TO/openjdk/repo/toolchain/jdk/build/build-openjdk17-linux.sh -d destdir builddir

The build writes jdk.zip and jdk-debuginfo.zip to destdir.

2. Updating the platform prebuilts from a local build

rm -rf PATH/TO/internal/repo/main/prebuilts/jdk/jdk17/linux-x86
mkdir PATH/TO/internal/repo/main/prebuilts/jdk/jdk17/linux-x86
unzip $DIST_DIR/jdk.zip -d PATH/TO/internal/repo/main/prebuilts/jdk/jdk17/linux-x86

Use jdk.zip to populate PATH/TO/internal/repo/main/prebuilts/jdk/jdk17/linux-x86.

3. Disable hyperthreading on gLinux server

Public Documents: How to disable or enable hyper threading on my Linux server

  1. Check whether hyperthreading is enabled and show all of the logical CPUs and their HT pair relationships.
grep -H . /sys/devices/system/cpu/cpu*/topology/thread_siblings_list | sort -n -t ',' -k 2 -u

  1. If hyperthreading is enabled, disable it. (assume there are n CPUs)

    Create a script to disable hyperthreading.

$ cat > /tmp/disable_ht.sh <<EOF
#!/bin/bash
for i in {0..n/2}; do
  echo "Disabling logical HT core $i."
  echo 0 > /sys/devices/system/cpu/cpu${i}/online;
done
EOF
sh /tmp/disable_ht.sh

4. Do the clean build of internal android

rm -rf `PATH/TO/internal/repo/main/out`
USE_RBE=false m -j32

5. Analyze PATH/TO/internal/repo/main/out/build.trace.gz

gunzip PATH/TO/internal/repo/main/out/build.trace.gz

Then you will get a json file called build.trace. Collect all file whose rule_name is javac and then the sum of their user_time is the total time. Two methods are provided below. Both work.

5.1 You can write a python script to analyze data

5.2 command line version

grep rule_name.*javac PATH/TO/build.trace | cut -d '"' -f 13 | cut -c2- | sed 's/.$//' | awk '{sum += $1} END {print sum}'