Category: Technology

While I was studying, I noticed that I wasn’t exactly happy with the cooling/cpu frequency scaling on my laptop. I use a nice program called powernowd which scales my CPU speed up and down depending on various factors related to system load. But I didn’t like how my setup was kind of “all or nothing.” When I am plugged into AC, I switch to “performance” mode which just runs me at 100% CPU frequency all the time (making my laptop hot, my fan noisy, but my machine fast), whereas when I’m unplugged I switch to “userspace” mode, which lets powernowd kick in, and he jumps about from 400mhz to the full 1.6Ghz based on load, keeping the machine cool but also making it feel a bit sluggish since if I’m overloading my CPU at 400mhz it’s already “too late” to pump it up, it will have already felt slow for at least an instant.

So I have this conflict: hot and responsive, or cool and sluggish. I thought, well, I must be able to come to a compromise.

I decided to take a look at powernowd’s code, and it turns out it’s written quite straightforwardly. Within 30 minutes of tinkering, I had a patch that did what I wanted. With another 30 minutes, I polished it and made it quite commitable.

Basically, I added a new mode called “COOLING” to powernowd, which runs your CPU a few notches below your full frequency (which I call your “cool_spot”), based on the following approach:

• if you have two frequencies available, you normally run with the lowest.
• if you have three frequencies available, you normally run with the second from highest.
• if you have four frequencies available, you normally run with the third from highest.
• if you have five or more frequencies available, you normally run with the fourth from highest.
• if your load goes above your specified trigger (“highwater” in the code), you jump to highest frequency. When it lowers (“lowwater”), you go down to your cool_spot, but not below it.

On my machine, I have 5 frequencies (1.6Ghz, 1.5Ghz, 1.4Ghz, 1.2Ghz, and 400Mhz), and so I normally am running at 1.2Ghz. This new COOLING mode runs while I’m plugged in, and keeps my machine nice and cool but still lets it immediately respond when I want to do something, like a workspace switch.

I then hacked the init.d script to have a BATTERY and AC mode, and switch between AGGRESSIVE and COOLING modes accordingly. Now, when I’m unplugged, I get the best battery life and pretty good performance, and when I’m plugged in I get a cool notebook with good performance.

I’ll probably post the patch after my midterms…

It’s really weird. Lately, I’ve been doing so much development in a *nix environment, that doing the development in Windows is really painful for me. I don’t have any of my good old UNIX tools, I don’t have hotkey-optimized user interfaces, I don’t have speed and control. But more than anything else, I don’t feel like I know what’s going on under the hood.

Today, to take a break from reading Philosophy, I decided to work a bit on this little Java Servlet project I’ve been hacking on. (Will be “released” later.) At some point this past summer, I decided to remove Linux from my main desktop machine and just consolidate all my Linux data onto one machine–this made my life easier so I didn’t have three total (one Windows, two Linuxes) places where my shit could be. But the sacrifice is that my laptop screen is small, so sometimes I want to develop with a big screen and thus want to use my desktop.

Web development, especially, makes sense for me under Windows, since I’m comfortable with the major graphic and web design tools (Photoshop, Dreamweaver, Illustrator) and don’t think the Linux “equivalents” (GIMP, Bluefish, Inkscape) are good enough.

But I decided–may as well have the code open on Windows too, since it’s not C hacking I’m doing, but Java. So I installed Eclipse, and the J2EE, and got cracking.

But under Windows, there are all sorts of gotchas. When my UNIX tool craving gets really bad, I need to drop into cygwin, which isn’t so bad. But without good workspace switching (I have VirtuaWin, but it kinda sucks), and without a customizable window manager, I am really much slower. But here’s the other weird thing I ran into. After awhile of coding, I realized that Eclipse wasn’t reading my JavaDoc information for the JDK (no cool descriptions in my autocomplete tooltips). So I go snooping around the preferences file and can’t find anything, I enable a billion options but no luck. But then, eventually, I realize that it’s very possible Eclipse is using a different JDK. In fact, I look in the dialog, and Eclipse is using some J2SE environment that some other application installed, not the J2EE I installed right before Eclipse. And that J2SE is missing the Java API source code and JavaDoc comments.

The reason this seemed so non-obvious to me is because I’m not used to systems which are completely fucking disorganized. Say what you will about Linux not being user friendly, but, by God, you won’t find it likely to find two different JDKs installed on my machine, and even if you do, only one will be getting used (thanks to Debian’s “alternatives” system). Every application on Windows statically compiles, includes its own libraries, and spews its shit all over the file system and registry. No database tracks it, so your system is a fucking nightmare.

I couldn’t even do a reasonable search to find the JDK I needed, either. It turns out it was in C:\Program Files\Sun\j2sdk1.4_02, which may not sound so bad, but considering on Linux I just think, “Where are libraries stored? /usr/lib” and then in there I think, “What is what I’m looking for called? j2sdk” I quickly find any Java environments in /usr/lib/j2sdk1.x-sun.

On my Linux system, which has not that much installed, I just ran a du -hs /usr/lib/ and got 1.7GB. That means on my relatively lightly-loaded Linux system, 1.7GB of raw 0s and 1s are sitting there waiting to be used as SHARED libraries. Meanwhile, on Windows, there could be any amount of duplication of the equivalent libraries, floating around in various Program Files directories.

I can’t believe there are acutally some Linux critics that believe we should be going in this direction, eliminating things like emerge, apt, and rpm and instead just have statically-compiled binaries that come with their own binary libraries and have users duplicating this stuff across their system. Not only is it insane from the point of view of giving control to the user, but it’s also just plain wasteful.

“Anyone who slaps a ‘this page is best viewed with Browser X’ label on a Web page appears to be yearning for the bad old days, before the Web, when you had very little chance of reading a document written on another computer, another word processor, or another network.” — in Technology Review, July 1996

If for nothing else, for Mac OS 9-style file browsing in Nautilus, a la this screenshot:

clicky clicky

I think the most evil thing about modern desktop computers is drive letters. Why didn’t Microsoft rid itself of this horrible concept earlier?

I’m working at a client’s house, trying to upgrade laptops from Windows 2000 to Windows XP. So, the last time I was here, I allocated 10GB of space at the front of the drive for the new system drive for XP. Now when I use the Windows installer to format it as NTFS, it marks it as “F:” Partition3. Which means, when I install XP, the system drive will be F:, and then when I eventually rid myself of the existing two drives, the system will break (probably with the infamous INACCESSIBLE_BOOT_DEVICE stop error).

So, the trick I’m going to use to get around this is prior to installing Windows, I’ll boot off a boot CD, hide both existing NTFS partitions, reboot, install Windows on the now-drive-C:, and then unhide those partitions later so that they show up as D: and E: (I hope).

Argh. The least the installer could have done is allowed me to hide the drives from within here. It takes for-ever to load up the Windows installer again.

For the last couple of weeks, my bedside reading has been this half-biography, half-autobiography on Linus Torvalds. I have to say, however, that the book is like two books mixed into one. Chapters alternate between Linus talking about his life and about big moments in Linux’s history to David Diamond describing modern-day Linus with a kind of forced wonder. Truthfully, Diamond comes off as a sycophant who could care less about Linus’s flaws and positive characteristics, and cares more about molding some kind of “image” of Linus as containing a humility and genius simultaneously. Near the end, I started only skimming the chapters not written by Linus. Diamond’s really not a good writer, either. (Sorry Dave.)

Truthfully, the book kind of pops the lid off Linux and makes you understand it as much less glamorous than say Wired Magazine described it to the public. Linus really just talks about not having a social life, sitting in his room with curtains covering his window, coding all day. Not exactly the ideal role model, I think. Don’t get me wrong, I love the Linux kernel (as much as one can love imperfect software), and Linus made a great contribution toward keeping the UNIX world and UNIX principles alive, but it’s just that I like to think of open source developers as something other than the stereotypical, introverted geek. In fact, much of Linus’s chapters is devoted to his apprehension about giving a public talk about Linux. When I think about the fact that I’ve given three or four of them to date, and enjoy it more every time, I see how different I am from this kind of stereotypical geek.

It also kind of made me dislike Linus. When I saw Revolution OS (a DVD on the rise of open source), the movie kind of endeared me to Linus’s practical nature as opposed to Richard Stallman’s religious idealism. I like idealism, but Stallman is really religious about it. And he’s bitter. Linus, on the other hand, has that great Northern European, “I’m just gonna go with the flow” attitude.

But this book made me realize that Linus is religious is his own sort of way. Included in the book is Linus’s flame war with Andy Tanenbaum on monolithic versus microkernel designs. Truthfully, I’ve studied operating systems and I’m not even sure which design is best, and Linus makes a decent argument of why microkernels end up being just as complex, or more complex than monolithic ones. But what I didn’t like is that in the flamefest, Tanenbaum said that deficiencies in MINIX were due to it being a hobby, and that he had duties as a professor. Linus responded, “Re 2: your job is being a professor and researcher: That’s one hell of a good excuse for some of the brain-damages of minix. I can only hope (and assume) that Amoeba [Tanenbaum’s future OS project] doesn’t suck like minix does.”

This just shows me that Linus really is an asshole sometimes. He states this outright in his book. So now, truthfully, I may like the open source movement, but I think I “at least dislike” two of its most major players (Torvalds and Stallman).

Finally, I think a clip from Tanenbaum’s website points out a nice principal in OS design:

Also, Linus and I are not “enemies” or anything like that. I met him once and he seemed like a nice friendly, smart guy. My only regret is that he didn’t develop Linux based on the microkernel technology of MINIX. With all the security problems Windows has now, it is increasingly obvious to everyone that tiny microkernels, like that of MINIX, are a better base for operating systems than huge monolithic systems. Linux has been the victim of fewer attacks than Windows because (1) it actually is more secure, but also (2) most attackers think hitting Windows offers a bigger bang for the buck so Windows simply gets attacked more. As I did 20 years ago, I still fervently believe that the only way to make software secure, reliable, and fast is to make it small. Fight Features.

I agree. But does a microkernel design actually reduce the overall size of the operating system, or does it just reduce the size of whatever you consider to be the “microkernel”? That is, just because a file system is implemented as a file system daemon talking to a driver subsystem through message passing doesn’t necessarily mean the file system, or driver subsystem, are secure. Insecurity could exist even at the boundaries, no? Not to mention instability.

I think Linus and Tanenbaum have to agree that this debate isn’t an open and shut case. The best kernel is probably one that mixes modularity, a strong kernel/userspace boundary, and some of the fancier features of a microkernel approach, while not sacrificing elegance of design or performance.

I’m organizing a group of people interested in hacking open source software in a team environment. Right now I’m calling it Free Coders at NYU, and have already set up a wiki and mailing list. This could end up being very cool. Next meeting is hopefully this coming Tuesday.

I set up a mailing list with GNU Mailman (link above), which was decently painless under Debian Sarge. The only annoying thing was utilizing my virtual e-mail address mappings which are stored in MySQL, but I figured out a trick for that.

I’ve already spoken, via e-mail, with an open source developer who works on gstreamer among other projects, Ronald S. Bultje. He has already tentatively agreed to do a talk for us sometime this year.