DTrace 使用 ustack() 丢失 Java 帧。在 Joyent SmartOS 基础架构容器上运行
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DTrace missing Java frames with ustack(). Running on Joyent SmartOS infrastructure container
提问by Gamlor
I cannot get any Java stack with dtrace in a Joyent SmartOS instance.
我无法在 Joyent SmartOS 实例中使用 dtrace 获取任何 Java 堆栈。
I tried the java:15.1.1image and a plain SmartOS 'base64' image, where I installed openjdk 8.
我尝试了java:15.1.1图像和普通的 SmartOS 'base64' 图像，我在其中安装了 openjdk 8。
I most basic example: cat Loop.java
我最基础的例子：cat Loop.java
[root@7e8c2a25-c852-4967-b60c-7b4fbd9a1de5 /demo]# cat Loop.java
class Loop {
public static void main(String[] args) throws InterruptedException {
while (true) {
System.out.println("Sleepy");
Thread.sleep(2000);
}
}
}
[root@7e8c2a25-c852-4967-b60c-7b4fbd9a1de5 /demo]# javac Loop.java
[root@7e8c2a25-c852-4967-b60c-7b4fbd9a1de5 /demo]# java Loop
I added the libdtrace_forceload.soas recommended.
我添加了libdtrace_forceload.so作为推荐。
export LD_AUDIT_64=/usr/lib/dtrace/64/libdtrace_forceload.so
It is a 64 bit JVM:
它是一个 64 位 JVM：
[root@7e8c2a25-c852-4967-b60c-7b4fbd9a1de5 /demo]# java -version
openjdk version "1.7.0-internal"
OpenJDK Runtime Environment (build 1.7.0-internal-pkgsrc_2015_05_29_19_05-b00)
OpenJDK 64-Bit Server VM (build 24.76-b04, mixed mode)
When I run dtrace, and use jstack, I get the C-stacks. However, the JAVA frames are the raw addresses, quite useless:
当我运行 dtrace 并使用 jstack 时，我得到了 C 堆栈。但是，JAVA 帧是原始地址，非常无用：
[root@7e8c2a25-c852-4967-b60c-7b4fbd9a1de5 ~]# pgrep -fn "java Loop"
32597
[root@7e8c2a25-c852-4967-b60c-7b4fbd9a1de5 ~]# dtrace -n 'syscall:::entry/pid == 32597/ { @num[ustack(20)] = count(); }'
dtrace: description 'syscall:::entry' matched 237 probes
^C
libc.so.1`__write+0xa
libjvm.so`_ZN2os5writeEiPKvj+0x128
libjvm.so`JVM_Write+0x34
libjava.so`writeBytes+0x1b5
libjava.so`Java_java_io_FileOutputStream_writeBytes+0x1f
0xffffbf7ffa612d98
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa606058
0xffffbf7ffa6004e7
libjvm.so`_ZN9JavaCalls11call_helperEP9JavaValueP12methodHandleP17JavaCallArgumentsP6Thread+0x31d
*snip*
I do see hotspot probes are available:
我确实看到有可用的热点探针：
[root@7e8c2a25-c852-4967-b60c-7b4fbd9a1de5 ~]# dtrace -l | grep hotspot | more
6103 hotspot32597 libjvm.so _ZN17VM_GenCollectFull4doitEv gc-begin
6104 hotspot32597 libjvm.so _ZN15VM_GC_Operation13notify_gc_endEv gc-end
6105 hotspot32597 libjvm.so _ZN26VM_GenCollectForAllocation4doitEv gc-end
6106 hotspot32597 libjvm.so _ZN35VM_GenCollectForPermanentAllocation4doitEv gc-end
6107 hotspot32597 libjvm.so _ZN17VM_GenCollectFull4doitEv gc-end
6132 hotspot32597 libjvm.so _ZN13instanceKlass15initialize_implE19instanceKlassHandleP6Thread class-initialization-end
6133 hotspot32597 libjvm.so _ZN13instanceKlass15initialize_implE19instanceKlassHandleP6Thread class-initialization-erroneous
6441 hotspot_jni32597 libjvm.so jni_DeleteLocalRef DeleteLocalRef-entry
6442 hotspot_jni32597 libjvm.so jni_DeleteLocalRef DeleteLocalRef-return
6443 hotspot_jni32597 libjvm.so jni_DeleteWeakGlobalRef DeleteWeakGlobalRef-entry
6444 hotspot_jni32597 libjvm.so jni_DeleteWeakGlobalRef DeleteWeakGlobalRef-return
6445 hotspot_jni32597 libjvm.so jni_DestroyJavaVM DestroyJavaVM-entry
6446 hotspot_jni32597 libjvm.so jni_DestroyJavaVM DestroyJavaVM-return
Question: Is there a way to list ustack helpers and if they are loaded? Any way to get the Java stack?
问题：有没有办法列出 ustack helper 以及它们是否已加载？有没有办法获得Java堆栈？
采纳答案by Joshua M. Clulow
In your example with untranslated Java stack frames, you appear to be using the ustack()action. In order to get translatedframes, I believe you ought to be using the jstack()action instead.
在您使用未翻译的 Java 堆栈帧的示例中，您似乎正在使用该ustack()操作。为了获得翻译的帧，我相信您应该改用jstack()动作。
