On Tue, Feb 18, 2014 at 11:06 AM, Andrew Savchenko <birc...@gmail.com> wrote: > On Mon, 17 Feb 2014 23:30:42 -0600 Canek Peláez Valdés wrote: >> On Mon, Feb 17, 2014 at 8:05 PM, Gevisz <gev...@gmail.com> wrote: >> [ snip ] >> > How can you be sure if something is "large enough" if, as you say below, >> > you do not care about probabilities? >> >> By writing correct code? > > Real world code without mistakes and larger than "Hello, world!" > exercises is not possible. Large systems must have error suppression > and correction techniques, modular and replaceable design is one of > them, KISS is another one. Systemd has none known to me.
It is modular. It is simple under the (larger) scope it tries to cover. It will have bugs (like *any* other non-trival program, as you said), obviously; but in time those bugs will be fixed and everything will be fine. >> >> I don't care about probabilities; >> > >> > If you do not care (= do not now anything) about probabilities >> > (and mathematics, in general), you just unable to understand >> > that debugging a program with 200K lines of code take >> > >> > 200000!/(10000!)^20 >> > >> > more time than debugging of 20 different programs with 10K lines of >> > code. You can try to calculate that number yourself but I quite sure >> > that if the latter can take, say, 20 days, the former can take >> > millions of years. >> > >> > It is all the probability! Or, to be more precise, combinatorics. >> >> My PhD thesis (which I will defend in a few weeks) is in computer >> science, specifically computational geometry and combinatorics. > > You're not the one here on the list with PhD (either defended or > near its end). And argument "Listen to me! I'm PhD here!" looks > miserable. Please stop this. And you please stop twisting my words. I mentioned my background only because someone was trying to teach me about combinatorics (which has nothing to do with this, BTW). It was not to give any weight to any other argument. >> >> I care about facts: FACT, I've been using systemd since 2010, >> >> in several machines, and I haven't had a single segfault. >> > >> > Have you ever tried forex? If yes, you should have been warned >> > that "no past performance guarantee the future one." >> >> I never said that. I trust the quality of the code, measured by my own >> judgment and bug reports, etc. Not past performance. >> >> And even if a bug goes by, then what? The world will end? > > This depends on what bug at what component occurred. Just imagine > pid 1 segfault on medical life support equipment. With systemd going > into embedded this is not just pure speculation, though, of course > medical stuff should have extra safeguards. But any FT or at > least HA setup is a combination of multiple layers. I do not want to > allow badly broken core component on mine setups even if its faults > may be compensated by other means. There are stable releases and testing releases; you put in live-dependent code the most rock solid software you have. The one that has been thoroughly tested and used. Really, "small" and "modular" don't guarantee anything either; anyhow you need to test it and use it before putting in live-dependent systems. > Yet again, I respect ones right to use whatever one wants, but I ask > to respect mine as well. That's why I propose a separate systemd > profile for those willing to use it. Then write. Just be aware that to write a systemd profile, you need to use systemd. >> >> Sorry, but it's you who doesn't know the matter at hand: kdbus was >> >> (and is) written by Greg Kroah-Hartman, Linus' right hand, and who >> >> works for the Linux Foundation. >> > >> > Lol, he seems to start to use the arguments like "You even do not know >> > my elder brother/acquaintance from the street nearby who can easily >> > hit you down!" >> >> If you don't think Greg's words have any weight in a Linux-related >> technical discussion, then I'm afraid we will need to agree to >> disagree on any technical subject. > > You know, common sense should always override person's prestige. > History knows many examples. Sir Isaac Newton enforced corpuscular > point of view on the light's nature. And while he was genius in other > physical aspects, he was mistaken here. Albert Einstein was rejective > to probabilistic nature of quantum mechanics and even proposed an > entangled particles paradox as an example of its "flawed" nature. > Though as we know these days such systems exist and are quite well > used in numerous experiments. My point is simple: do not blindly > adhere to someone's words, even if this person has high authority. > Common sense must prevail. Period. I don't blindly adhere to *anyone* points. There are arguments that Greg, Lennart and Kay had made which I don't agree with. But in the big picture I'm with those guys. And so it seems the majority of the Linux world; you say it's because monetary reasons. I said it is because of the technical advantages of systemd. Regards. -- Canek Peláez Valdés Posgrado en Ciencia e Ingeniería de la Computación Universidad Nacional Autónoma de México
