Did an interview for FOSDEM about SystemTap. It discusses a wide range of topics. About when I got involved with Free Software, working for Red Hat, how FOSDEM helped the libre Java community, getting Fedora more observable by adding static markers into programs, the history of observation tools (tracers, profilers, debuggers) on GNU/Linux, comparisons to [...]
Really looking forward to Fosdem next month. This year I will be giving a talk What is my system doing – Full System Observability with SystemTap during one of the main tracks. There will be some demos of the new systemtap java and python tracing support that I blogged about earlier.
Michael Meeks published a though provoking essay called Some thoughts on Copyright Assignment. It is a must read when working with Free Software projects that request legal assignment of contributions to a corporation.
It contains sane recommendations both for individual contributors, project leaders and corporations seeking assignments.
Just checked in support for getting java backtraces from hotspot through systemtap. This is the next step in making not just the kernel and native programs observable, but also runtime based languages with SystemTap. And it is pretty powerful. It allows you to answer the question “How did I get here?” in combination with any [...]
At FudCon, David Malcolm, Jon VanAlten, Will Cohen and I sat down, had some fun and made tracing python methods through systemtap possible:
0 python(20122): => search_function in Lib/encodings/__init__.py:71
15 python(20122): => normalize_encoding in Lib/encodings/__init__.py:49
37 python(20122): <= normalize_encoding
170 python(20122): => <module> in Lib/encodings/utf_8.py:8
193 python(20122): => IncrementalEncoder in Lib/encodings/utf_8.py:18
206 python(20122): <= IncrementalEncoder
251 python(20122): => IncrementalDecoder in Lib/encodings/utf_8.py:22
264 python(20122): [...]
Currently stuck at heathrow airport… But I will make it to Canada somehow for FudCon. Hopefully with some nice systemtap jstack java hotspot backtrace examples.
They finally actually started to work. Weeee!
After my somewhat cranky post about the JDK 7 M5 binaries being distributed under not very free and social terms. I was really happy to see Mark Reinhold’s announcement of the JDK 7 M5 + Jigsaw binary packages:
These binaries are licensed under the GPL (v2) with the Classpath Exception, plus the Assembly Exception.
Thank you Mark! [...]
Mark Reinhold announced JDK 7 Milestone 5 which is derived from OpenJDK7. Lots of people contributed to that. But sadly Sun decided they weren’t going to release this as Free Software. I wanted to research this JDK7 M5 and compare it to the work we did on OpenJDK and IcedTea, but apparently I am not [...]
Since the various OpenJDK servers are seeing major ongoing outages the last couple of days it might be good to point out that at least the source code from the master jdk6 and jdk7 mercurial forests do have backups: http://classpath.wildebeest.org/hg/. These are read-only of course. You will also find backups of the various IcedTea mercurial [...]
Wow, just wow! Look at all those new features in the just released GNU Debugger 7.0:
Python scripting support
Reverse debugging, Process record and replay
Non-stop debugging
Multi-architecture debugging
Multi-inferior, multi-process debugging
GDB now has an interface for JIT compilation
Tracepoints may now be conditional
Multi-byte and wide character set support
New /r and /m [...]
Josh announced SystemTap 1.0
Experimental support for unprivileged users, cross-compiling for foreign architectures, matching C++ class and namespace scopes, reduced runtime memory consumption, reduced dormant overhead in userspace markers, bug fixes, and more…
I am happy this is finally out the door. Designating something with 1.0 is always special. And it is always hard to decide when [...]
With the recent releases of Systemtap 0.9.9 and IcedTea7 1.11 some pieces of the systemtap whole system observability picture come together. On top of the “meta-probes” in hotspot (for garbage collection, monitors, object allocation, threads, etc.) we now also see the java language level tracing coming to life.
Always wondered what really was going on when [...]
Just did an aptitude dist-upgrade to get planet.classpath.org and the main IcedTea backup server from Debian Etch to Debian Lenny. Pretty smooth.
Needed to adjust some apache2 NameVirtualHost settings as outlined in the release notes. And sadly, had to pin mercurial to 0.9.5, since newer versions don’t work nicely with the forest extension and serving hg [...]
Another nice feature for Systemtap 0.9 was added by Josh Stone. Systemtap can collect data from any variable in scope at a probe point using the DWARF debug info. You can even dereference pointers, access struct members, array elements, etc. This is very powerful when collecting data during a trace and the systemtap runtime makes [...]
We recently released Systemtap 0.9 and one of the nice new features included is the user space markers that Stan Cox has been working on. They were designed so that they should be compatible with dtrace static user space markers, so you can immediately take advantage of them if your program already has those included. [...]
Sarah has been publishing sets of pictures from the Fosdem Free Java Meeting.
IcedTea 1.4 got released this week. And while it is full of new exciting stuff, you really should check out the XRender support by Clemens Eisserer. Especially if you often use java through remote X. It just flies! Trying it out is easy as soon as the new IcedTea hits a distro near you:
java -Dsun.java2d.xrender=True [...]
Sometimes people ask me what Red Hat actually pays me for. Aren’t you working on something java related? Although my manager has been very generous and allows me to spend some (but not too much!) time on helping out the free java efforts, my main job is in the engineering tools group (gcc, gdb/Archer [formerly [...]
Looking for a handy reference of all the talks in the Free Java developer room at Fosdem 2009 in Brussels, Saturday 7 and Sunday 8 February? Look no further! PDF Poster and ODG Poster.
Our libre-java meeting at Fosdem is approaching quickly. February 7 and 8 in Brussels, Belgium. If you want to give a talk, do a demo or have some general presentation/hack-session in our room, please act quickly so we can still schedule it (the deadline is end of this week!).
This is what will be at [...]
planet.classpath.org moved servers and if done correctly nobody will notice (except for the new server having a totally sweet favicon ). But if you do happen to notice anything odd with the planet after the move, then please do yell and scream.
Without much fanfare systemtap 0.8 was released a little while ago. There is one little tidbit in the release notes that does warrent some excitement though:
User space probing is supported at a prototype level, for kernels built with the utrace patches.
So what does that mean? Take for example the para-callgraph.stp script:
$ stap para-callgraph.stp ‘process(“/bin/ls”).function(“*”)’ -c [...]
Paul wrote about “Fedora 10 around the corner!” and said something really nice:
Last, but certainly not least, I want to thank you, the reader, if I haven’t already. You’re part of our community too, and without you we would be diminished. Free software isn’t just about bits and bytes, it’s about people, about [...]
This post by Kirill Grouchnikov from Pushing Pixels made me sad:
Trust is hard to build and easy to destroy
Are we really doing that badly? Ever since the full GPL release by Sun of the reference implementation of Java as OpenJDK and the positive wave that IcedTea brought to unite the existing libre java communities pushing [...]
There is always a lot going on in the low levels of the GNU Toolchain (gcc, binutils, gdb, etc) but since it is so low level and sometimes a bit specialised it is hard to keep up. Luckily Nick Clifton started a blog writing a monthly GNU Toolchain Update. This month saw lots of [...]