On 11/17/2014 10:20 AM, Volker Simonis wrote: > Hi Maynard, > > I'm currently looking at your changes. At first glance they look good. > > I could open a simple core file which contained both, interpreted and > compiled frames: > > $ jstack ./images/j2sdk-image/bin/java core.7034 > ... > Thread 7035: (state = IN_VM) > - sun.misc.Unsafe.putAddress(long, long) @bci=0 (Interpreted frame) > - Crash.crashIt(sun.misc.Unsafe, int) @bci=10, line=8 (Interpreted frame) > - Crash.doIt() @bci=45, line=23 (Compiled frame) > - sun.reflect.NativeMethodAccessorImpl.invoke0(java.lang.reflect.Method, > java.lang.Object, java.lang.Object[]) @bci=0 (Interpreted frame) > - sun.reflect.NativeMethodAccessorImpl.invoke(java.lang.Object, > java.lang.Object[]) @bci=100, line=62 (Interpreted frame) > - sun.reflect.DelegatingMethodAccessorImpl.invoke(java.lang.Object, > java.lang.Object[]) @bci=6, line=43 (Interpreted frame) > - java.lang.reflect.Method.invoke(java.lang.Object, > java.lang.Object[]) @bci=56, line=498 (Interpreted frame) > - Crash.main(java.lang.String[]) @bci=32, line=31 (Interpreted frame) > > The one thing that doesn't currently work is "jstack -m" (i.e. "mixed > mode" for java and native frames). Are you aware of this? Hi, Volker, Yeah, I knew about this problem and forgot to mention it in my patch posting. I started looking at it this morning, and so far, I have at least fixed the UnmappedAddressException. But now I'm getting different results on little endian vs big endian ppc64 systems. On BE, I either get no symbol names (i.e., "?????") or wrong symbol names. On LE, I seem to get correct symbol names for the first symbol (either __pthread_cond_wait or __pthread_cond_timedwait) and the last symbol (start_thread) of each stack, but everything in between is "?????".
> > Regarding your "test.java" example - how do you use it? > > If I just attach with jstack to the Java process which runs > "test.java" I get the correct stack trace of all threads. But I think > that's actual no SA-functionality but a VM-feature (the same that can > be triggered by sending kill -SIGQUIT to java process). > > If I attach with "jstack -F" I see the problems you mentioned. First I > didn't saw any frame at all which confused me but then I also saw the > two cases mentioned by you. I'll need to have a closer look what > happens. I was just running the 'test' java app and, in another session, killing it with SIGSEGV. To be honest, I wasn't aware of the 'jstack -F' option. -Maynard > > Regards, > Volker > > > > On Fri, Nov 14, 2014 at 7:09 PM, Maynard Johnson <mayna...@us.ibm.com> wrote: >> When Hotspot SA tools jmap, jstack, and jsadebugd are run against a core >> file, they fail with the following runtime exception: >> >> OS/CPU combination linux/ppc64 not yet supported >> >> I will post a patch set that adds this support. The patch set consists of >> the following patches: >> >> PATCH 1/2: Updates to non-Java files to support linux/ppc64 Hotspot SA with >> core files >> >> PATCH 2/2: New PPC64 class files (and updates to generic files) to support >> linux/ppc64 Hotspot SA with core files >> >> These two patches apply cleanly to a November 13 pull of the jdk9-dev >> upstream sources. >> >> ------------ >> Open issues: >> ------------ >> 1) The jstack tool does not print a stack entry for the 'main()' method of >> the Java >> workload (attached) under test. For example: >> >> (Note: Addresses and method signatures elided for brevity.) >> >> Thread 24358: (state = IN_JAVA, current Java SP = null >> ) >> - java.lang.String.getChars(...) @bci=58, line=814, pc=..., >> Method*=... (Compiled frame; ... imprecise) >> - test.run_test() @bci=80, line=33, pc=..., Method*=... (Compiled >> frame) >> ==> (Expect an entry for test.main() here) >> >> 2) The jstack tool sometimes prints what appears to be two complete stacks >> for the Java workload. For example: >> >> Thread 24779: (state = IN_JAVA, current Java SP = null >> ) >> - java.lang.String.getChars(...) @bci=58, line=814, pc=..., >> Method*=... (Compiled frame; ... imprecise) >> - test.run_test() @bci=80, line=33, pc=..., Method*=... (Compiled >> frame) >> - test.get_my_chars(...) @bci=39, line=15, pc=..., Method*=... >> (Compiled frame) >> - test.run_test() @bci=92, line=34, pc=..., Method*=... (Compiled >> frame) >> >> Again, the 'test.main' method is missing, but there's also the >> anomaly of the >> test.run_test' method showing up twice in the stack, implying that it >> is called >> by 'test.get_my_chars' at line 15. But that that is not accurate. In >> fact, run_test >> does call String.getChars at line 33 *and* it calls test.get_my_chars >> at line 34 -- >> but these are totally distinct call graphs. Somehow, we are seeing >> these two distinct >> stacks in the core file, which seems impossible. >> >> --------- >> >> Any help offered on these two open issues would be greatly appreciated. >> >> -Maynard >
