Common Sense 4 Common People

The Law of Late Projects

Very recently a good friend of mine, Prof.Vasilis Vassalos, made a comment on Facebook about Parkinson's law by referring to this article.

Parkinson's law says that all work expands to fill all time available for its completion.

This has be proven statistically to be very true, so nobody can doubt it. However some of the consequences of this law often go unnoticed as the law's wording and meaning gets twisted and turned over to suit one's needs.

FireWire 1.6 Gbps and 3.2 Gbps announced by DAP Technology!

Last week I told you about the forthcoming news on 1.6 Gbps and 3.2 Gbps FireWire.

Now, here is the official press release from DAP Technology!!!

Have fun!
Dimitris Staikos

FireWire moving forward

Two weeks ago I visited the Vision Show 2009 exhibition in Stuttgart, Germany.

Two very important things happened there with regards to FireWire (IEEE 1394) technology.

1. DAP Technology made a demo of their S1600/S3200 solution. That's 1.6Gbps and 3.2Gbps respectively. It worked fine over 10m standard FireWire cables.
   The demo was semi-public and DAP will make a relevant press release within the next days.
2. Two companies demonstrated their S800-over-Coax cable solutions, using the S800 coax transceivers of Eqcologic.

They are both great news for FireWire, because they show that FireWire is still moving forward.

Have Fun!
Dimitris

Rules of program optimization

I recently watched a recorded presentation of Prof.Diomidis Spinellis, author of a couple of world famous books on programming, like "Code Quality". At some point Mr.Spinellis discussed the issue of program optimization and mentioned some famous quotes related to this issue, quotes that were also listed in his "Code Quality" book:

• The First Rule of Program Optimization: Don't do it.
• The Second Rule of Program Optimization (for experts only): Don't do it yet.

These come from M.A.Jackson. It is hard to exaggerate how much I agree.

I would like to add my own rules to the list :-) Maybe others have said similar words, but now I copy from my own brain:

• The 3rd Rule of Program Optimization: Make sense of it in the real world first.
• The 4th Rule of Program Optimization: Measure it and justify it before you commit to it.

Programmers often set sail to optimize a piece of code, just because it is plain for all to see that this piece of code CAN be optimized. However, you should do some serious thinking first to see whether it makes sense to optimize this piece of code. How often is it run, under which paths, how long does it take to execute, etc. For example don't optimize code to turn a 0.1 msec into a 0.01 msec if that runs once every minute.

Does it make sense to optimize a process that is executed once a day, if that process takes 10min, 20min, 120min, 360min? Would it make sense to optimize the 10min to 1min (10/1 improvement), the 120min to 30min (4/1 improvement) or the 360min to 120min (3/1)?

You definitely can't tell the answer by looking at the numbers. Maybe the 360min procedure runs at the end of the day, after all employees are gone, so no one benefits from the improved performance, but then the backups can be scheduled earlier. Or the 120min process runs over lunch break, so having it finished before people return from lunch does not make that much of a difference.

That's the meaning of the 3rd rule, don't look at the code searching for optimizations, look at the real world for optimizations.

The 4th rule is a bit drastic. After you decided to optimize the code, do some measurements. Careful measurements of the old implementation, careful measurements of the new implementation. If the improvement is NOT worth the while, then you might as well scrap the optimization. Throw it away. You thought you had good reason, you made extensive changes but didn't get the improvement you expected; no hurt feelings, just dump it.

Code complexity and maintainability are far more critically important than a minor performance optimization. KISS should be the topmost priority, not writing code that makes programmers feel good about themselves ;-)

Have Fun!

Dimitrios Staikos

The Internet says...

Today I was walking the streets of downtown Stuttgart in Germany and of all things possible, I was looking for a post office. I was given some directions by some friendly local, but I still couldn't find it. So I asked another passerby for assistance.

He didn't know, but he immediately popped out his cell phone and told me "Let me check on the Internet". I don't know why, but I felt that this event transitioned me into a whole new era. Most likely because it was the first time in my life that a completely random passerby would access the Internet in order to offer me the assistance I was looking for.

What amazed me even more was the way he formulated his reply soon after:

"The Internet says it's on Marienstrasse 19".

Have Fun!
Dimitris Staikos

PS: Beware of what the Internet says... The post office wasn't there ;-)

Microsoft update KB967723 installation error

For days now Vista has been bugging me about an update that just would not install (KB967723).
Even if I would shutdown the machine, it would just try and fail.
And not simply fail... but give me an amazing error code (80070490) which to cut a long story short meant that some internal database of updates was corrupt and I had to repair installation from the Vista CD. What???? Over my dead body!

Can you see the big picture here? I was minding my own business and one more Digital Misfortune came my way uninvited. But don't get me wrong here. If there is ONE technological feat that I admire in this world that is Microsoft Update. I just can believe such a thing is working. One major screw up (or security breach) and millions of computers can become unusable; just the security requirements of this blew my mind away... So I forgive them some glitches.

Anyway, since I had to debug this issue, I thought I might as well write a couple of lines about it, so that other poor souls like me might get a better chance when searching for an answer.

By searching the net and reading other posts I found some people mentioning that in similar situations they downloaded the standalone installer for the update and surprisingly enough it installed without problems.
Now that should ring some bells...
It is a seemingly non-rational action but it often has results.
So I downloaded the standalone installer for KB967723 and bingo! It installed and problem solved :-)
Isn't digital life so sweet?

Have Fun!
Dimitris Staikos

DELAY command implemented as batch file

Hi

I always had a strange fascination about batch files in Windows. I like automation, but for some reason I don't like using an elephant gun (Perl, Powershell) to shoot a mosquito. Plus I like the automation stuff to work on any PC, without having to install anything new. The Windows shell commands look totally crippled, but there is more to it than meets the eye.

Too much power management can kill you

QUIZ
You can tell that something is wrong when:

1. Something that usually takes half an hour is not finished after 5 hours OR
2. Yet another piece of technology is functioning in unintended ways.

A couple of days ago I read a tip about 4 mistakes that can kill VM performance.
#4 was: The default power option of Windows Server 2008 upon installation is set to "Balanced".
Sure as hell it was set to Balanced, so I corrected that one.
But tonight something else happened that was related to power management.
A backup to network folder was taking far too long.
How nice... One more problem to solve...
I check the network utilization and see that it was 100%.
Now that's a bit unusual... Just a bit...
I take a better look and what do I see?
Link Speed 10Mbps!!!!!
Excuse me??? Where did that come from?
To cut a long story short, the Intel network adapters came with a default setting that made them reduce the link speed if the machine is idle. The machine was certainly not idle, but still the link speed was reduced... go figure.
I deactivated the setting and got back my 1Gbps with a healthy 30% utilization and my backup was finished in the next 10 minutes.

That's why I say too much power management will kill you...

Have Fun!
Dimitris Staikos

Updating WDF on Vista checked build

I had some trouble today with the Windows 7 WDK when I tried to install a driver on the checked build of Windows Vista x86. Actually I found the answer after searching around a little bit, but since all the information was scattered around, I thought it might be nice to put it all together under one roof.

Here are the basic facts:

• Vista SP2 comes with WDF version 1.7 while the Win7 WDK has version 1.9.
• When installing the driver on the checked build of an OS you must supply the checked build of the WDF coinstallers.
• The checked build of the coinstaller is named WdfCoInstaller01009_chk.dll but you have to rename it to WdfCoInstaller01009.dll in your installation package.
• The checked WDF coinstallers are not capable of updating Windows Vista.
• This means that they cannot upgrade the installed WDF version.
• This translates to this error message, if you attempt to install the driver:
  Error 776: The client of a component requested an operation which is not valid given the state of the component instance.
• And this means that you have to upgrade Vista WDF manually, reboot and then install your driver (still the installation package must include the checked coinstaller).

Here is how to do it in a nutshell:

1. Open the checked coinstaller DLL in Visual Studio or any other tool capable of exporting resources.
2. Export the WDFCAB_RESOURCE from RCDATA resources and save the file as a .cab file.
3. Open the cab and extract the .EXE with the long name (Microsoft Kernel-Mode Driver Framework Install-v1.9-Win2k-WinXP-Win2k3.exe).
4. Open an elevated command prompt and navigate in that directory. Step 5 will NOT work on a non elevated command prompt, although it requests UAC elevation.
5. Execute: "Microsoft Kernel-Mode Driver Framework Install-v1.9-Win2k-WinXP-Win2k3.exe" /X
6. A bunch of files are exported, among which are wdf01000.sys and wdfldr.sys.
7. Now you must manually override these .sys files on the target system running on the checked build. This means you have to bypass SFP (System File Protection).
8. Copy the existing files as a backup measure.
9. Change the security of these two files so that (a) your account appears as the owner and (b) give your account Full Control (you have to do that explicitly - ownership is not enough).
10. Override the two files with the checked versions of WDF 1.9.
11. Pray and reboot :-)
12. After rebooting install your driver.

Have fun :-)
Dimitris Staikos

Visual Studio Debugging Tip

More than words can say...


ntStatus is declared as DWORD or anything equivalent to unsigned long.
Works both for Visual Studio 2008 and Visual Studio 2005.
Fare well Error Lookup ;-)

Have Fun!
Dimitris Staikos