PPC-AIX Port to FreeBSD PowerPC Support

Fri Feb 12 07:08:22 UTC 2016

Hi Curtis,

I think it makes sense to post this on the bsd list too.

See my comments inline.

On Fri, Feb 12, 2016 at 7:26 AM, Curtis Hamilton <hamiltcl at verizon.net>
wrote:

> Thomas/Volker,
>
>
>
> Just wanted to give you an update on my bsd/ppc64 porting effort.  I’m
> using the standard bsd openjdk8 port, as the bsd mercurial needs freebsd
> specific patches.
>
>
>
> I’ve made progress modding the linux/ppc files to work under bsd and can
> successfully build a native (ppc64) JVM.  Here’s the output I get executing
> ‘java –version’
>
>
>
> root at lenoil8:/usr/ports/java/openjdk8/work/openjdk/build/bsd-ppc64-normal-server-slowdebug/jdk/bin
> # ./java -version
> openjdk version "1.8.0_72-debug"
> OpenJDK Runtime Environment (build 1.8.0_72-debug-b15)
> OpenJDK 64-Bit Server VM (build 25.72-b15-debug, mixed mode)
> root at lenoil8:/usr/ports/java/openjdk8/work/openjdk/build/bsd-ppc64-normal-server-slowdebug/jdk/bin
> #
>

Great Job!

> I can compile and execute the basic “hello world”.  However, compiling
> more complicated java code results in a core dump.  See the following:
>
>
>
> root at lenoil8:/usr/ports/java/openjdk8/work/openjdk/build/bsd-ppc64-normal-server-slowdebug/jdk/bin
> # ./javac HelloWorld.java
> root at lenoil8:/usr/ports/java/openjdk8/work/openjdk/build/bsd-ppc64-normal-server-slowdebug/jdk/bin
> # ./java HelloWorld
> Hello, World
> root at lenoil8:/usr/ports/java/openjdk8/work/openjdk/build/bsd-ppc64-normal-server-slowdebug/jdk/bin
> # ./javac zip.java
> Trace/BPT trap (core dumped)
> root at lenoil8:/usr/ports/java/openjdk8/work/openjdk/build/bsd-ppc64-normal-server-slowdebug/jdk/bin
> # ./javac LargeZip.java
> Trace/BPT trap (core dumped)
> root at lenoil8:/usr/ports/java/openjdk8/work/openjdk/build/bsd-ppc64-normal-server-slowdebug/jdk/bin
> #
>
> As you can see this is a debug build and I’ve been able to tell from the
> core dump, using gdb, that it’s getting a signal 5 at abort.
>
>
>

I think SIGTRAP is used by the ppc JIT for some things (implicit
nullchecks? Volker would know better). So, SIGTRAP must be handled for this
to work.

The JVM has a central signal handler, entry point is "signalHandler" in
os_<os>.cpp, and then it goes on to, in your case, JVM_handler_bsd_signal()
in os_bsd_ppc.cpp.

So, make sure that

1) SIGTRAP is handled by this signal handler - I think, by default bsd does
not install a signal handler for SIGTRAP. See
os::Bsd::install_signal_handlers(), and compare it with the Linux version.

2) Then, SIGTRAP must be handled in JVM_handler_bsd_signal(). Compare with
the SIGTRAP handling for Linux (os_linux_ppc.cpp). But if you copied that
code, maybe SIGTRAP handling is already in place and (1) was all that was
missing.

Also note: The jvm normally writes a error log on crashes which is very
useful ("hs_err_<pid>") but in your case it was not written at all, because
no signal handler was installed for SIGTRAP. So, if you took care of (1)
but (2) is still missing, you may still crash but with a real error report
log this time.

Side note: Magnus Ihse Bursie is cleaning up and repairing the BSD port,
see:
http://mail.openjdk.java.net/pipermail/bsd-port-dev/2016-January/002739.html

His changes are not yet committed, but he posted a webrev with his changes (
http://cr.openjdk.java.net/~ihse/JDK-8147795_addendum-bsd-source-patches/webrev.01/).
It may make sense to integrate this in your build, he did some worthwhile
fixes.

Kind Regards, Thomas

> Any recommendations on what to look at or how to further debug?
>
>
>
> Regards,
>
>
>
> Curtis
>
>
>
> *From:* Curtis Hamilton [mailto:hamiltcl at verizon.net]
> *Sent:* Monday, January 11, 2016 3:29 PM
> *To:* 'Thomas Stüfe' <thomas.stuefe at gmail.com>
> *Cc:* 'Volker Simonis' <volker.simonis at gmail.com>; '
> ppc-aix-port-dev at openjdk.java.net' <ppc-aix-port-dev at openjdk.java.net>
> *Subject:* RE: PPC-AIX Port to FreeBSD PowerPC Support
>
>
>
> Thomas,
>
>
>
> Thanks for the vector check!
>
>
>
> I agree that the AIX os is quite different from other unices (I have an
> old PowerStation 220 in my collection).  However, the ppc-aix-port was the
> first that contained code specific to the ppc.  Since there isn’t a ppc-bsd
> port, I needed somewhere to start.  PPC code for both AIX and Linux can be
> found in the same port.   The ports available on FreeBSD currently do
> contain any of the ppc headers or code.  So I decided to use a port that
> already had the ppc code and go from there.
>
>
>
> Now that ppc code is being integrated into a more universal port, I just
> need to check which jdk8 port to work with.
>
>
>
> Any recommendation?
>
>
>
> Regards,
>
> Curtis
>
>
>
> *From:* Thomas Stüfe [mailto:thomas.stuefe at gmail.com
> <thomas.stuefe at gmail.com>]
> *Sent:* Monday, January 11, 2016 11:23 AM
> *To:* Curtis Hamilton <hamiltcl at verizon.net>
> *Cc:* Volker Simonis <volker.simonis at gmail.com>;
> ppc-aix-port-dev at openjdk.java.net
>
> *Subject:* Re: PPC-AIX Port to FreeBSD PowerPC Support
>
>
>
> Hi Curtis,
>
>
>
> I am not sure that AIX ppc would be the best source for an BSD port. AIX
> os port contains a large number of AIX specifics and it is quite a bit
> different (sometimes, needlessly) from the other Unices. It is also a
> moving target, at least on jdk9, as we changed a lot in the AIX os port and
> will change more until the next feature close.
>
>
>
> So, it may be that linux ppc would be a better porting source for a bsd
> ppc port.
>
>
>
> Kind Regards, Thomas
>
>
>
>
>
>
>
>
>
>
>
> On Mon, Jan 11, 2016 at 3:21 PM, Curtis Hamilton <hamiltcl at verizon.net>
> wrote:
>
> Volker,
>
>
>
> Thanks for the response.
>
>
>
> Yes, I’m using the mercurial jdk7u ppc-aix version.  The reason I used
> this port version was because I was more familiar with the build layout of
> jdk7 versus jdk8/jdk9.  And it seemed like an easier target to start with,
> since it already supported ppc64 on AIX and Linux.
>
>
>
> Full disclosure, I’ve been successful in building zero vm for both jdk7
> and jdk8 on ppc64/FreeBSD.   They both work great.  The system performance
> is somewhat sluggish, but usable.  So I decided to see if I could build
> native ppc64 versions leveraging the existing AIX and Linux ppc64 support
> in the ppc-aix-port, since the bsd-port lacks support for PowerPC.
>
>
>
> I’m aware of the integration effort for jdk9.  So on your advice, I will
> start working with ppc-aix jdk8u.  I don’t want anyone to waste time with
> jdk7u. Although my efforts with this older version is not completely wasted.
>
>
>
> I look forward to contributing to the ppc64/bsd port OpenJDK integration
> effort.
>
>
>
> Regards,
>
> Curtis
>
>
>
> *From:* Volker Simonis [mailto:volker.simonis at gmail.com]
> *Sent:* Monday, January 11, 2016 5:22 AM
> *To:* Curtis Hamilton <hamiltcl at verizon.net>
> *Cc:* ppc-aix-port-dev at openjdk.java.net
> *Subject:* Re: PPC-AIX Port to FreeBSD PowerPC Support
>
>
>
> Hi Curtis,
>
> no, I'm not aware of any effort to port the ppc64 port to BSD.
>
> My first question is why are you building jdk7. It is quite old and we
> don't actually support it any more. It was also never integrated into the
> main jdk7u branch. I'd strongly recommend to use at least the jdk8u
> version. If you plan to contribute the ppc64/bsd port for integration into
> the OpenJDK, this has to be done into the head revision (currently jdk9)
> anyway. Once it's there, it may be possible to downport it to jdk8u (but
> not to jdk7u because that on doesn't even contain the ppc64 port).
>
> That said, which version of jdk7u are you using? Is it the one from
> http://hg.openjdk.java.net/ppc-aix-port/jdk7u/ ?
>
> One problem you may encounter with jdk7u is that it was never compiled
> with new versions of gcc. I see you are using gcc4.8 but we used 4.1.2 back
> then when we were doing the port.
>
> Another problem is that we didn't support the serviceability agent in
> jdk7u. Support for the SA agent on Linux/ppc64 (but not for AIX) was added
> in jdk8. The error you see in vmStructs.cpp is most probably from SA
> coding. How does your file vmStructs_bsd_ppc.hpp looks like. As you can
> see, vmStructs_linux_ppc.hpp is empty in jdk7u for the ppc64 port while it
> has some code in jdk8u-dev and jdk9.
>
> Unfortunately the place in vmStructs.cpp where the error happens is deeply
> nested macro coding so it's hard to say what's wrong from the error
> message. You could preprocess the file and post that to the list, maybe we
> can see more. Just issue the following command from a shell from within
> /usr/ports/tmp/jdk7u/build/bsd-ppc/hotspot/outputdir/bsd_ppc64_compiler2/product:
>
>  g++48 -DBSD -DPPC64 -D_ALLBSD_SOURCE -D_GNU_SOURCE -DPRODUCT
> -I/usr/ports/tmp/jdk7u/hotspot/src/share/vm/prims
> -I/usr/ports/tmp/jdk7u/hotspot/src/share/vm
> -I/usr/ports/tmp/jdk7u/hotspot/src/share/vm/precompiled
> -I/usr/ports/tmp/jdk7u/hotspot/src/cpu/ppc/vm
> -I/usr/ports/tmp/jdk7u/hotspot/src/os_cpu/bsd_ppc/vm
> -I/usr/ports/tmp/jdk7u/hotspot/src/os/bsd/vm
> -I/usr/ports/tmp/jdk7u/hotspot/src/os/posix/vm -I../generated
> -DHOTSPOT_RELEASE_VERSION="\"24.80-b11\""
> -DHOTSPOT_BUILD_TARGET="\"product\"" -DHOTSPOT_BUILD_USER="\"root\""
> -DHOTSPOT_LIB_ARCH=\"ppc\" -DHOTSPOT_VM_DISTRO="\"OpenJDK\""
> -DDEFAULT_LIBPATH="\"/lib:/usr/lib:/usr/local/lib\"" -DTARGET_OS_FAMILY_bsd
> -DTARGET_ARCH_ppc -DTARGET_ARCH_MODEL_ppc_64 -DTARGET_OS_ARCH_bsd_ppc
> -DTARGET_OS_ARCH_MODEL_bsd_ppc_64 -DTARGET_COMPILER_gcc -DCOMPILER2 -fPIC
> -fno-rtti -fno-exceptions -pthread -fcheck-new -mpowerpc64 -pipe
> -DDONT_USE_PRECOMPILED_HEADER -O3 -fno-strict-aliasing -D_LP64=1 -m64
> -mminimal-toc -mcpu=powerpc64 -mtune=power5
> -minsert-sched-nops=regroup_exact -mno-multiple -mno-string
> -DSAFEFETCH_STUBS -DINCLUDE_TRACE=1 -Werror -Wpointer-arith -Wconversion
> -Wsign-compare    -E
> /usr/ports/tmp/jdk7u/hotspot/src/share/vm/runtime/vmStructs.cpp
>
> Regards,
>
> Volker
>
>
>
> On Sun, Jan 10, 2016 at 3:04 PM, Curtis Hamilton <hamiltcl at verizon.net>
> wrote:
>
> Hello,
>
> I’d like to know if there’s been any work done to support PPC for *BSD?
>
> I’ve hacked both the AIX and Linux PPC headers but have been unsuccessful
> in building HotSpot.  All modules seem to build with the exception of
> VMStructs.cpp with the below error.
>
> /usr/ports/tmp/jdk7u/hotspot/src/share/vm/runtime/vmStructs.cpp: In static
> member function 'static void VMStructs::init()':
> /usr/ports/tmp/jdk7u/hotspot/src/share/vm/runtime/vmStructs.cpp:3015:
> error: cannot convert 'pthread**' to 'pid_t*' in initialization
>
> Build log is attached.
>
> Thanks in advance!
>
>
>
> Curtis
>
>
>
>
>
>
>
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