Insignificant Bits

Renaming your class variables to shorter names reduces your EJB network footprint. Finally, those people who said that removing vowels from variable names improved performance are vindicated! Ok, well they were correct already in Javascript, but that doesn’t count.

Let’s dump the last useful feature in Java. What castles in the sky are people building these days?

The stats from smolt are pretty interesting if, like all stats, entirely useless. Some curiousities:

• i686 still beats x86_64 by a ton
• A (very) few people change their runlevel
• Acer is high in the vendor list, I guess they are still killing the netbook market
• People don’t configure their swap appropriately
• SMP is now the norm, outside of embedded kit anyway
• I want a 4+ GHz cpu
• No one uses omfs :( …I guess I need to submit a profile.

There comes a time in every budding kernel developer’s life that he has to debug a mysterious lockup, and nothing will do but a serial console. Well, for my future recollections, here’s how to set it up:

1. Get out your handy pl2303-based usb to serial adapter, because chances are good your laptop doesn’t have a serial port
2. Build your kernel with CONFIG_USB_SERIAL_CONSOLE=y
3. Add to your kernel command line: console=ttyUSB0,115200 console=tty0
4. Hook your computer up to the other computer via a null-modem cable (man, these are pricey these days, $30 for something no one still uses?)
5. Set up minicom to use your serial port, say ttyS0, at 115200 baud, 8N1, and turn off all the modem init strings
6. Don’t bother futzing with getty, you only need it if you want to also allow logins over serial. For logging, it’s unnecessary

Now, start minicom on computer 2 and reboot your computer under test. If all goes well, you’ll capture a panic on the serial console. If all goes poorly (my case), you’ll have a lockup with no oops. The usual thing to try in this case is adding “nmi_watchdog=1″ to the command line, which will use the non-maskable interrupt to break into any frozen code. Also, if you have CONFIG_DETECT_SOFTLOCKUP set, hopefully after 60 seconds or so you’ll get a soft lockup warning.

In my case, I still have a hard lock with no output. Ho hum.

Capitals warm-up
Originally uploaded by bluesterror

Did you see the game last night? Yeah, we were there! Did you see us on TV? Huh, what half-time show? Ohhh…. you are talking about that other game, what is it called, footsball? Nah, didn’t watch that one. But we did see Ovechkin get his second hat trick of the year in a 7-4 rout of the Senators yesterday. So be sure to get your 14 free toppings on your pizza this week.