Older blog entries for twisti (starting at number 34)

22 Jan 2010 (updated 7 May 2011 at 06:17 UTC) »

JSR 292 server compiler support in JDK 7 b80

About two weeks ago I pushed the remaining changes (6894206, 6893081, 6829187, 6893268) for C2 invokedynamic support on x86 which were integrated into HotSpot 17 b07.  Meanwhile HS17b07 has been integrated into JDK 7 b80 and the latter has been released.

With two changesets John Rose pushed lately (6891770, 6914665), which have been integrated into JDK 7 b79, you can run now invokedynamic enabled programs with decent performance.  Additionally we tuned inlining heuristics a little (6912063) to be able to use inline-related switches in a product VM and to not count generated MethodHandle adapters.

And here is how it works (gwt is a simple testcase for guardWithTest):

$ java -server -XX:+UnlockExperimentalVMOptions -XX:+EnableMethodHandles -XX:+EnableInvokeDynamic gwt

You can also run JRuby benchmarks, like bench_fractal.rb which prints a nice fractal (we need to tune inlining heuristics a little to get good performance):

$ bin/jruby --server -J-Djruby.compile.invokedynamic=true -J-XX:+UnlockExperimentalVMOptions -J-XX:+EnableMethodHandles -J-XX:+EnableInvokeDynamic -J-XX:InlineSmallCode=2500 -J-XX:MaxInlineSize=50 bench/bench_fractal.rb

(To see the fractal you have to try it yourself :-)

The next thing will be C1 support.  I'm currently working on it and it's almost finished.

Syndicated 2010-01-22 13:33:16 (Updated 2010-01-22 21:33:16) from twisti's weblog

12 Jan 2010 (updated 7 May 2011 at 06:17 UTC) »


It's exactly one year ago that I started to work for Sun.  Nice!  I wasn't sure that I will make the anniversary facing the merger with Oracle.  Anyway, I learned a lot in this first year and I'm really looking forward to the next years at Sun (or whatever the company will be called then).

Syndicated 2010-01-12 09:25:35 (Updated 2010-01-12 17:25:35) from twisti's weblog

2 Oct 2009 (updated 7 May 2011 at 06:17 UTC) »

Compiz and the Meta key in Emacs

When I switched back to OpenSolaris I wanted to use Compiz instead of Metacity to have at least some eye candy.  After switching to Compiz I noticed that the Meta key is not working in Emacs.  Since it worked in the "Normal Visual Effects" mode I was sure it's related to one of the Compiz plugins that was turned on by default in the "Custom" mode.

After some trial and error I found out that the "Group and Tab Windows" in the "Window Management" section is the bugger.  It uses a couple of <Mod4> key bindings and one of them is <Mod4>x.

Disabling that plugin makes M-x work again in Emacs.

Syndicated 2009-10-02 15:33:22 (Updated 2009-10-02 22:33:22) from twisti's weblog

2 Oct 2009 (updated 7 May 2011 at 06:17 UTC) »

Back to OpenSolaris (and DBX)

A few months ago I got a new laptop (unibody MacBook Pro) and I decided to stay with Mac OS X because of two main reasons: Broadcom WiFi and the touchpad.  Everything looked very slick and worked, obviously, out-of-the-box.  A perfect OS for private use.

But developing on that OS is a pain in the...  Apple's GDB drives me nuts!  It was crashing every now and then and was 95% of the time not able to call simple C++ instance methods.  Completely useless!!!

I filed a few bugs in Apple's Radar and tried to get the FSF guys to support Darwin in their GDB.  Some help in both cases, but nothing I could really use.

So, yesterday I decided to bite the bullet, install OpenSolaris again, use NDIS Wrapper for the Broadcom WiFi and to give the xorg-input-synaptics package of SFE a try for the touchpad.  The first one is working flawlessly, but only in 32-bit mode.  That means I can't test 64-bit HotSpot locally.  Well, I can live with that for some time.  I didn't have time to try the second one yet but I hope it works.

Glad to be back.

Syndicated 2009-10-02 15:14:58 (Updated 2009-10-02 22:14:58) from twisti's weblog

9 Sep 2009 (updated 7 May 2011 at 06:17 UTC) »

JSR 292 work update

I'm still working on HotSpot compiler support for JSR 292.  The progress is actually very good and inlining is already working in C2.  Although there are still some problems with scavenging oops in nmethods and you have to stick to UseSerialGC if you want to give it a try.  But John Rose is working on a fix for that.

While not working on inlining I started porting JSR 292 support to x86_64.  I've already commited the interpreter support and compiler support is in the works and almost finished.

In the meantime Charles Nutter introduced another dynamic language, called Surinx, which uses invokedynamic and "the solid performance of Surinx bodes very well for JRuby's future."  That sounds good.

Syndicated 2009-09-09 12:32:57 (Updated 2009-09-09 19:32:57) from twisti's weblog

3 Jul 2009 (updated 7 May 2011 at 06:17 UTC) »

Turning off format=flowed in Thunderbird

I just noticed that I'm sending emails with format=flowed in Thunderbird, which is not intentional.  A quick search revealed that both sending and displaying emails in flowed format can be turned off. Just change the following preferences to:

mailnews.display.disable_format_flowed_support = true
mailnews.send_plaintext_flowed = false


Syndicated 2009-07-03 09:38:16 (Updated 2009-07-03 16:38:16) from twisti's weblog

7 May 2009 (updated 7 May 2011 at 06:17 UTC) »

More bit-twiddling intrinsics

Today I pushed the changes for 6823354 which adds intrinsics for {Integer,Long}.{numberOfLeadingZeros,numberOfTrailingZeros}() methods.  The speedups are quite good:

Integer Long
numberOfLeadingZeros numberOfTrailingZeros numberOfLeadingZeros numberOfTrailingZeros
Intel Nehalem 32-bit 3.18 3.96 1.36 1.90
64-bit 3.83 3.74 2.02 2.17
AMD Shanghai 32-bit 1.94 3.55 0.98 2.44
32-bit w/ lzcnt 4.90 - 1.46 -
64-bit 2.52 3.09 1.86 3.26
64-bit w/ lzcnt 6.77 - 3.71 -
UltraSparc T2 32/64-bit 2.01 2.22 1.55 1.91

"w/ lzcnt" in the table means the numbers are using AMD's LZCNT (count leading zeros) instruction which is part of SSE4a.

The SPARC intrinsics need a hardware implementation of the POPC instruction.

Yet I haven't found a real-world application that uses these methods extensively (including bitCount), but if anyone knows one, please let me know.

Syndicated 2009-05-07 11:03:50 (Updated 2009-05-07 18:10:47) from twisti's weblog

17 Apr 2009 (updated 7 May 2011 at 06:17 UTC) »

A lot of changes need a lot of testing

I'm still working on adding an AddressLiteral class on SPARC (6822110) to actually finish the load shortening optimizations (6814842) and to remove useless I2L conversions (5057225).  But 6822110 became really huge and it needs a lot of testing.  I hope I can push it next week.

Syndicated 2009-04-17 11:49:27 (Updated 2009-04-17 18:49:27) from twisti's weblog

1 Mar 2009 (updated 7 May 2011 at 06:17 UTC) »

Skype on Solaris

[It almost took me a full day to get it working, so I will write down what I have done to get there.]

Actually I wanted to use Ekiga, but it does not work very well in OpenSolaris and not many "normal" (reads: non-geek) people use such clients.  And I wanted to reach some of my "normal" friends, which almost all are using Windows and most possibly Skype.

Maybe there will be a native OpenSolaris port of Skype someday, but for now we have to go different ways.

You can use the "seamless mode" from VirtualBox to run Skype on Windows.  Feature-wise this is probably the best solution, but you need to install Windows (not an option for me).  And I'm not 100% sure that sound will work in VirtualBox as it always complained about problems opening some PCM devices.

Instead of using Windows  you could use Ubuntu to run Skype and there is the possibility of transferring the install into a BrandZ Linux zone.  And that's what I wanted to do.

First of all I tried the CentOS 3 image from here, but it's too old to run a recent Skype and it is really hard to find older versions on the web (well, I found one but I couldn't get it working).

Then I tried to install Ubuntu 8.04 and CentOS 5 in VirtualBox, but both was so slow that I canceled that and searched for CentOS image tar's instead.  Fortunately I found this site where you can download CentOS 4 and 5 images as tar files.

So I installed CentOS 5 in a zone and that worked perfectly.  But when I wanted to start Skype I got this error.  Seems like it's a known problem and not related to zones.

Then CentOS 4... yeah... GCC C++ ABI problems.  Skype wants 3.4.4, but CentOS only has 3.4.3.

So... what else is left?  Debian.  And I wanted to get it running in a zone...

I downloaded a businesscard install image, because it's the smallest one (32M), and installed the smallest possible system in VirtualBox.  That install was actually very fast.  Then got Skype for Debian, scp'ed it into the VirtualBox, installed all required packages (don't forget xbase-clients for SSH X11 forwarding), tar'ed up the whole root filesystem, scp'ed the image back to the native system and installed it into a zone.  The zone install does not work out-of-the-box, obviously Debian is not RHEL or CentOS, so I hacked it a bit.

Execute the following commands in VirtualBox before you tar up the whole filesystem:

$ mkdir /etc/sysconfig
$ mkdir /etc/rc.d
$ touch /etc/rc.d/rc.sysinit

and the zone install will be successful.

[I have to add here that the Debian zone does not boot properly (try zlogin -C), so it would be better to get it working in CentOS 5, but that doesn't really matter.  Log into the zone with zlogin and start the SSH daemon.]

Then I logged into the zone via SSH (only root works, as can be read here too) and started Skype...


It came up and signed in successfully!  Chat worked, calls didn't.

This is because BrandZ only maps OSS and the Skype Debian version uses ALSA. But hey, that last hurdle must be cleared too, right?

So, simply download the static OSS version of Skype and use that one...

Voila!  Skype calls on OpenSolaris!

Easy, wasn't it?

Syndicated 2009-03-01 18:19:47 (Updated 2009-03-02 02:19:47) from twisti's weblog

3 Feb 2009 (updated 7 May 2011 at 06:17 UTC) »

My first bugfix

Today I pushed my first bugfix.  To be honest, I had a little help from Tom Rodriguez who pointed me to the right function.  I hope someday the time will come when I can help you, Tom :-)

Syndicated 2009-02-03 15:07:35 (Updated 2009-02-03 23:07:35) from twisti's weblog

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