java - rhel 7.4 上的 ibm java 太慢了

Question

我正在尝试在新安装的 Rhel 7.4 上安装 IBM Installation Manager(agent.installer.linux.gtk.x86_64_1.9.0.20190715_0328.zip)。我测试了 java，因为 GUI 太慢了，结果如下；正如你所看到的，oracle java 比 IBM java 快得多!为什么会发生这种情况？

[root@adige bin]# uname -a
Linux adige 3.10.0-693.el7.x86_64 #1 SMP Thu Jul 6 19:56:57 EDT 2017 x86_64 x86_64 x86_64 GNU/Linux

[root@adige bin]# time /installations/unpacked/installationManagerX86_64_1.9/jre_8.0.5035.20190626_1229/jre/bin -version
java version "1.8.0_211"
Java(TM) SE Runtime Environment (build 8.0.5.35 - pxa6480sr5fp35-20190418_01(SR5 FP35))
IBM J9 VM (build 2.9, JRE 1.8.0 Linux amd64-64-Bit Compressed References 20190417_414854 (JIT enabled, AOT enabled)
OpenJ9   - 777635f
OMR      - 16b77d7
IBM      - 72459d3)
JCL - 20190409_01 based on Oracle jdk8u211-b25

real    0m20.185s    <<<<<< Lasting 20 seconds.
user    0m0.169s
sys 0m0.034s


[root@adige bin]# time /tmp/java-8-oracle/jre/bin/java -version
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)

real    0m0.098s
user    0m0.079s
sys 0m0.031s

Answer 1

这很奇怪。在轻负载的系统上，实际时间和用户时间通常非常相似。例如

$ time bin/java -version
java version "1.8.0_211"
Java(TM) SE Runtime Environment (build 8.0.5.36 - pxa6480sr5fp36-20190510_01(SR5 FP36))
IBM J9 VM (build 2.9, JRE 1.8.0 Linux amd64-64-Bit Compressed References 20190502_415899 (JIT enabled, AOT enabled)
OpenJ9   - 46e57f9
OMR      - 06a046a
IBM      - 0b909bf)
JCL - 20190409_01 based on Oracle jdk8u211-b25

real    0m0.090s
user    0m0.093s
sys 0m0.012s

我还没有听说过 RHEL 上的 IBM Java 存在任何类似问题。挂载/installations/unpacked/installationManagerX86_64_1.9 的文件系统是否有可能出现问题？