trace openjdk from systemtap

here are several different tactics to trace openjdk from systemtap.

The first relies on sys/sdt.h dtrace-style markers compiled into the JVM, but not dbgsym data:

% stap -L 'process("/usr/lib/jvm/java*/jre/lib/*/server/libjvm.so").mark("*")'

If this shows an empty result, (and if I have the ubuntu libjvm.so path right), then this suggests your openjdk was compiled without the sys/sdt.h stuff, so this option is closed to you. If it shows a lovely list, you can use those .mark probes directly, or snarf/adapt a copy of the hotspot*.stp tapset sources from anywhere and transcribe it into your .stp file, or let stap find it via

% stap -I PATH ...

The second method relies on dwarf debuginfo compiled into the JVM, for which the dbgsym* stuff should be handy. If that is installed properly,

% stap -L 'process("/usr/lib/jvm/java*/jre/lib/*/server/libjvm.so").function("*")'

should show a gajillion functions. You may not have the benefit of tapsets, but with clever choice of functions, you should be able to get some decent tracing going.

The third method relies on byteman to do intra-JVM self-instrumentation under systemtap control. This requires no java dbgsym, but does require byteman and a bunch of auxiliary stuff. If this is available and compiled into the ubuntu systemtap, then something like:

% stap -e 'probe java("org.my.MyApp").class("^java.lang.Object").method("foo(int)")
           { println($$parms) }'
posted @ 2016-07-01 13:46  zengkefu  阅读(397)  评论(0编辑  收藏  举报