Older blog entries for Zaitcev (starting at number 146)

Seems like I found a yet another deadlock in the 2.4.x quota code, which is not unexpected. Generally speaking, filesystem operations may poke quota as a side effect, but quota itself has to call filesystem to update the quota file. The result is an invitation for deadlocks. The one I am talking about involved 3 (THREE) processes, forming a circle. Who could have thought that such things occur in real life outside of CS classes with their dining phylosophers :)

Quota was pretty buggy in all UNIX-es which I encountered, and Linux is strangely reliable in this area. Perhaps this lures users into thinking that quota is something that can actually be used.

BTW, quota in Linux bears the dubious distinction of the only piece of core code lifted wholesale from BSD by some Russian guy. I am wondering how BSD people manage their deadlock city.

hacker sez...
    Which brings me to my second rant.. car manufacturers. For the same reasons.. in the US, there is no state that allows you to exceed 65mph that I'm aware of, and yet domestic cars are sold with the ability to go 120mph plus. Sure, you can jam your foot on the pedal and go as fast as you want.. but you're breaking the law. I wonder how many unnecessary injuries and deaths could be prevented if cars simply could not exceed the maximum speed limit, unless modified third-party? [...]
... and puts his very big foot into his mouth. The guy is quite ignorant.

For one thing, Montana allows any speed (during daytime), providing it is "reasonable and prudent", and Arizona has 75mph speed limit.

Second, special tracks exist, where people pay money for several laps of driving fast (such as Thunderhill in Illinois and Laguna Seca in California).

Third, cars are speed limited. For instance, Dodge Neon is limited to 118mph, which is the rating of its stock Goodyear Eagle tires, coincidently.

Bite me, stinking Nazi.

About five years ago, a guy was driving a back street at 25mph (according to police investigation), when a 3 year old boy sat on a skateboard and rolled from inclined driveway across the street in Newark, CA. Plop, plop. So, let's install PCM limiting cars to 10mph. That sure will cut on unnecessary death, right?

Goverment can do a lot of paternalistic shit to reduce "unnecessary" injury and death. In the process, the life becomes a living hell.

My assesement of Rob Levin's work differs from Martin Pool's. In an entry, mbp said that lilo did not show the code. I think lilo did, actually. He produced the OPN network, which is his "code", or something which you can examine and decide if it's worth anything.

I figure some people like it, so if they want to donate money to lilo for it, that's fine. If lilo wants to ask money, that's fine too. Personally, I see no value in OPN whatever, and I have no trouble tuning off discussions about it. I do not see how this can irritate anyone. We saw worse diaries at advogato than lilo's.

Now, the idea to swap handles for no reason is irritating. If someone are irritated by that, they should refrain from certifying rlevin. The raph's code takes care of the rest, like magic.


Regarding microkernels, I opine that idea extremely important. Consider UML, for instance. It's a Linux microkernel, basically. BTW, existance of UML is an experimental fact, not opinion.

Researchers of golden age of classic microkernels, who attended USENIX Symposium on Micro-Kernels and Other Kernel Architectures (no joke, that was the title, I've got the proceedings) failed to realize two little facts about microkernels (ok, two little opinions of mine):

  • Performance differential cannot be erased. Ergo, classic and other microkernels are to be used where their well known advantages overwhelm performance disadvantage (e.g. QNX is the best example of it). C is "slower" than assembly too. Not to mention Python.
  • Applications do need decent (rich) execution environment, not bare hypervisor.

In respect to Billy shelf, I am having extremely hard time to believe that a hole may be drilled wrong in them. They all are made by a pattern drilling, for crying out loud. I respect Raph so much that I went around the house to examine our own Billy's. It may be remotely possible to offset the pattern vertically, depending what tooling was actually used. Hmmm... I guess we should never underestimate the corruptive ingenuity of a sweatshop worker. I did get a defective item once from Ikea, it was the closet organizer with poor welding. But I never saw a hole of component mismatch.

On a related thought, a great Russian Jewish physist Leo Landau was said to send his wife a telegram from a resort: "TOOTH POWDER WONT OPEN STOP PLEASE ADVISE STOP", followed by another one "TOOTH POWDER OPEN STOP". (If you do not know what a telegram is imagine e-mail sent over a 50.5 (fifty point five) baud serial, printed on a bi-color label tape, and delivered to you by a carrier boy).

I am so happy that I do not have to read the idiotic Forth propaganda, essays of our religious nut and W-phobia by morally bankrupt leftists that I feel an urge to write an entry about it. Truly a red day in the calendar.

I see a little problem with people who fall below the default cut-off, because it will take an enormous effort to get back. It only takes one diary entry about Iraq to get through the "event horizon", and then you are there forever. Suppose that one day sye, mrslicker, and mglazier wisen up. How are they to signal the rest of the readers about it?

BTW, I pretty much gave up reading articles, but we had an influx of intresting articles recently. The SCM one was ok, for instance. That's pretty cool.

We are a little busy here at work, so no content today. Make sure you read the message Red Hat Nullifies Differences between bash, csh".

(Yes I subscribed for LWN too)

The EE Times (website) ran an article about Sun staying on track with their Infiniband plans. Intel does not seem to let up on their software development plan either. Recently Mellanox uploaded their driver to the Intel's Sourceforge project. I guess this is another case of reports about someone's death being exaggerated.

The Infiniband saga does not affect me personally anymore, because Red Hat shifted me to other department (so-called "CE"). On, and in another news, we have GES renamed into CE, so now we have two CEs. That will confuse Microsoft spies, I suppose...

18 Sep 2002 (updated 18 Sep 2002 at 17:46 UTC) »

So, a patched 2.5.33 boots on sparc and appears fully functional, as much as a 2.5 version can. IDE is bust, so I have to use NFS root. The whole thing was anticlimactic in the extreme.

I rigged a dead NVRAM with two AA batteries in my IPC, so sun4c is the next target.

A teacher taped my speech in a Public Speaking class. It was horrendous when I watched it. I did not even remotely realize how bad my pronunciation was.

14 Sep 2002 (updated 14 Sep 2002 at 17:20 UTC) »

Working with a 2.5 kernel means a game of catch-up, but it seems I hold up better this time (compared to 2.3). The latest catch-up session included PCI configuration space access API changes and a new serial drivers (I think those are "RMK" drivers, aren't they). I found that new serial stuff basically requires "console=ttyS0,9600" argument if you run a serial console. To work around it in sunsu.c would be counterproductive, and I want to discard sunsu.c anyway in favor of a multiplatform support for 8250.c. I went on and made PROLL to download kernel command line from TFTP server, so now we have a new release of this undying program (I think "venerable" would be too complimentary).

[update: Funny how the BSD guy broke Advogato without any CSS, just using <b>. Way to go, pal, real friendly.]

jpick: The Rearden Steel (now Digeo) is a good place, they have Andrew Morton there. By all means check it out. I had a chance to work there couple of years ago, but their HR person tried to contact me with an HTML mail and I do not read those... So I went to Red Hat. Funny how it all worked out :-)
30 Aug 2002 (updated 30 Aug 2002 at 01:51 UTC) »
goingware is experienced, so I assume he understands what he is doing. In contrast, I consciously decided to stay away from the embedded programming, unless economic hardships make me.

From a free software actor point of view, embedded programming is a very alien, hostile world.

First, it integrates with hardware much more than our big computer programming does. In hardware, patents reign supreme, and the whole old school of closed source engineering is thriving. This spills over to the embedded programming. The air in embedded companies is stiff.

Second, embedded projects are as diverse as their platforms. This places high barriers in the way of code reuse, at least as far as community bulding is concerned. Embedded programmers spend their lives working on code which is never reviewed by anyone and 95% of it is discarded before it reaches a product.

And third, embedded programming is populated by dorks, historically. Most of those people do not know how to quote an e-mail, and they do not care to learn, just to bring one example.

Actually, it is much worse than I am making it sound, but you have be in it to feel the oppression.

I am sure that Advogaters will point out exceptions, and in fact I saw one myself, in pre-RedHat Cignus. Count yourself fortunate if you end in a company like that, but do not bet on it.

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