Size difference of Java.base image between OSX and Linux

[Jola I Waldek]

>> From: David Holmes <david.holmes at oracle.com>
>> Date: October 28, 2016 at 17:30:22 EDT
>> To: Waldek Kozaczuk <jwkozaczuk at gmail.com>, jigsaw-dev at openjdk.java.net
>> Subject: Re: Size difference of Java.base image between OSX and Linux
>> 
>>> On 29/10/2016 3:32 AM, Waldek Kozaczuk wrote:
>>> 
>>> I used jlink to create minimal custom JRE image on OSX and Linux and I noticed there is a significant difference in size. The Mac version takes 21M where the Linux one takes 30M which means Linux version is 50% bigger than Mac.
>>> 
>>> Is it as you would have expected? Why is size difference so big?
>>> 
>>> I noticed that lib/modules is similar in size (1M difference) but the biggest difference is between ./lib/server/libjvm.dylib (12 M) and ./lib/amd64/server/libjvm.so (21 M). So the linux version of the shared library object is almost twice as big on linux (both 64 bit).
>> 
>> Nothing jlink related. This is a question for the build-dev and/or hotspot-dev folk. It seems that in 8u libjvm is <1MB larger on Linux than OSX. However in 9 the Linux version has steadily grown to ~21M while the OSX version has shrunk to ~12M. It may be related to the debugging/symbol info still present in the library.
>> 
>> David
>> 
>>> Here is the command I used to create the image:
>>> jdk-9/bin/jlink --module-path jdk-9/jmods --add-modules java.base --output image_target --strip-debug --compress=2
>>> 
>>> Here is a detailed listing of files on Mac:
>>> 68K    ./bin/java 68K    ./bin/keytool 8.0K    ./conf/net.properties 4.0K    ./conf/security/java.policy 40K    ./conf/security/java.security 4.0K    ./conf/security/policy/limited/default_local.policy 4.0K    ./conf/security/policy/limited/default_US_export.policy 4.0K    ./conf/security/policy/limited/exempt_local.policy 4.0K    ./conf/security/policy/README.txt 4.0K    ./conf/security/policy/unlimited/default_local.policy 4.0K    ./conf/security/policy/unlimited/default_US_export.policy 20K    ./include/classfile_constants.h 4.0K    ./include/darwin/jni_md.h 76K    ./include/jni.h 80K    ./include/jvmti.h 4.0K    ./include/jvmticmlr.h 68K    ./lib/jli/libjli.dylib 16K    ./lib/jspawnhelper 4.0K    ./lib/jvm.cfg 204K    ./lib/libjava.dylib 32K    ./lib/libjimage.dylib 12K    ./lib/libjsig.dylib 92K    ./lib/libnet.dylib 68K    ./lib/libnio.dylib 44K    ./lib/libosxsecurity.dylib 48K    ./lib/libverify.dylib 32K    ./lib/libzip.dylib 7.2M    ./lib/modules 4.0K    ./lib/security/blacklist 4.0K    ./lib/security/blacklisted.certs 112K    ./lib/security/cacerts 8.0K    ./lib/security/default.policy 0B    ./lib/security/trusted.libraries 12K    ./lib/server/libjsig.dylib 12M    ./lib/server/libjvm.dylib 4.0K    ./lib/server/Xusage.txt 104K    ./lib/tzdb.dat 4.0K    ./release
>>> 
>>> Here is a detailed listing of files on Linux:
>>> 
>>> 4.0K    ./lib/security/blacklisted.certs
>>> 8.0K    ./lib/security/default.policy
>>> 4.0K    ./lib/security/blacklist
>>> 0    ./lib/security/trusted.libraries
>>> 104K    ./lib/tzdb.dat
>>> 12K    ./lib/jexec
>>> 4.0K    ./lib/amd64/jvm.cfg
>>> 108K    ./lib/amd64/libnet.so
>>> 72K    ./lib/amd64/jli/libjli.so
>>> 132K    ./lib/amd64/libjimage.so
>>> 220K    ./lib/amd64/libjava.so
>>> 36K    ./lib/amd64/libzip.so
>>> 21M    ./lib/amd64/server/libjvm.so
>>> 4.0K    ./lib/amd64/server/Xusage.txt
>>> 12K    ./lib/amd64/server/libjsig.so
>>> 88K    ./lib/amd64/libnio.so
>>> 12K    ./lib/amd64/libjsig.so
>>> 64K    ./lib/amd64/libverify.so
>>> 8.2M    ./lib/modules
>>> 4.0K    ./release
>>> 4.0K    ./include/jvmticmlr.h
>>> 4.0K    ./include/linux/jni_md.h
>>> 20K    ./include/classfile_constants.h
>>> 80K    ./include/jvmti.h
>>> 76K    ./include/jni.h
>>> 4.0K    ./conf/security/policy/limited/default_local.policy
>>> 4.0K    ./conf/security/policy/limited/default_US_export.policy
>>> 4.0K    ./conf/security/policy/limited/exempt_local.policy
>>> 4.0K    ./conf/security/policy/README.txt
>>> 4.0K    ./conf/security/policy/unlimited/default_local.policy
>>> 4.0K    ./conf/security/policy/unlimited/default_US_export.policy
>>> 40K    ./conf/security/java.security
>>> 4.0K    ./conf/security/java.policy
>>> 8.0K    ./conf/net.properties
>>> 12K    ./bin/java
>>> 12K    ./bin/keytool
>>> 
>>> Regards,
>>> Waldek
>>> 
>>> Sent from my iPhone
>>>