Use default Parallel GC again

Build times on Travis CI went up by up to 12min

Author: fniephaus

mx.graalsqueak/mx_graalsqueak.py

@@ -16,7 +16,6 @@
     '-Xss64M',  # Increase stack size (`-XX:ThreadStackSize=64M` not working)
 
     # GARBAGE COLLECTOR (optimized for GraalSqueak image)
-    '-XX:+UseG1GC',
     '-XX:OldSize=256M',         # Initial tenured generation size
     '-XX:NewSize=1G',           # Initial new generation size
     '-XX:MetaspaceSize=32M',    # Initial size of Metaspaces
@@ -26,7 +25,6 @@
     '-Xss64M',  # Increase stack size (`-XX:ThreadStackSize=64M` not working)
 
     # GARBAGE COLLECTOR (optimized for Travis CI)
-    '-XX:+UseG1GC',
     '-Xms4G',                   # Initial heap size
     '-XX:MetaspaceSize=32M',    # Initial size of Metaspaces
 ]

scripts/template.graalsqueak.sh

@@ -28,7 +28,7 @@ fi
 # Parse arguments, prepare Java command, and execute.                 #
 #######################################################################
 PROGRAM_ARGS="--polyglot"
-JAVA_ARGS="-Xss64M -XX:+UseG1GC -XX:OldSize=256M -XX:NewSize=1G -XX:MetaspaceSize=32M"
+JAVA_ARGS="-Xss64M -XX:OldSize=256M -XX:NewSize=1G -XX:MetaspaceSize=32M"
 
 for opt in "$@"; do
   case $opt in