|
|
Subscribe / Log in / New account

Gentoo Optimizations Benchmarked (Linux Magazine)

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 30, 2009 19:51 UTC (Fri) by ledow (guest, #11753)
In reply to: Gentoo Optimizations Benchmarked (Linux Magazine) by flewellyn
Parent article: Gentoo Optimizations Benchmarked (Linux Magazine)

I don't think people ever really consider the customisability of Gentoo as the main factor in using it. I certainly wouldn't go looking at Gentoo if I needed to heavily customise a PC with certain features (or absence thereof).

The basic rule is roll your own, for most things, if you need that level of customisation (and very, very, very few people do). Why would you *want* to compile without a feature, for instance, (as opposed to just disabling it in the configuration) unless you're talking embedded applications? - and there are thousands of embedded distros and patches for those purposes that do a much better job than Gentoo ever could.

I don't see customisability as a valid reason that crosses the entire Gentoo userbase, and all the Gentoo users I know claim the speed gains are the main reason they use it (and some for the coolness factor of "it compiles itself!").

And then I point out the mathematics to the speed-freaks. Say that it saves you 1% of CPU *constantly*. The time and effort to configure and compile and then use that system (and I rarely hear of Gentoo systems running for years at a a time) is vastly outweighed by that initial compile. And the support issues. And the rare corner cases that knock the averages back down.

Most PC's *aren't* running at 100% CPU, and swapping to disk because of shortage of RAM all the time (if you are, you need a better fix than recompiling with -03!). You've actually sacrificed large chunks of CPU time in order to save tiny amounts in use when the processor rarely hits 100% anyway, or is bottlenecked by I/O rather than CPU or RAM.

In fact, most of the machines I manage (desktops, servers, personal PC's, etc.) hover around 5%-10% usage, averaged over a full year, unless I'm playing a game on them. The compile might be "dead" time that you weren't using the computer in anyway, but you are wasting so much time and effort in order to get 1% improvement (possibly, maybe, assuming everything is configured correctly and it compiles first time). Use that 1% of time to take a normal distro and pare it back a little, or optimise the SINGLE application that takes the most power (e.g. on a web server instance, maybe the Apache process, etc.). You'll save similar amounts of effort in much less time and with much, much less trouble.

Now these optimisations *might* get you that 1% on your frame rate in heavy games but now we've turned Gentoo into "go faster stripes", somewhere in the realm of "oxygen-free gold cables" but instead of audiophiles we're talking gamers (Linux is hardly renowned for being friendly to that community anyway!). Go buy another stick of RAM or overclock by a few percent and you could blow all those optimisations out of the water in seconds.

The trade-off isn't there, and Gentoo seems to only ever have been an interesting experiment with no actual, practical purpose. Otherwise people like Google would be using it to claw 1% off their power usage or get 1% faster queries. It's a toy, in my eyes. Interesting. Fun to mess with. Something to point at. But it is just a toy.

All the machines I manage run bog-standard kernels, with bog-standard compiled software for i586... we don't get performance issues, we don't have compatibility issues (Motherboard dead? Slap the drive into any Pentium or above machine and carry on) and everything just works fine. It also takes a little over ten minutes to port a complete image from one machine to one on an entirely different setup.

Seriously, where is the *application* for Gentoo?


to post comments

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 30, 2009 20:20 UTC (Fri) by nix (subscriber, #2304) [Link] (3 responses)

What I find it valuable for is that you can arrange to have all the source
for your whole system, exactly as it's running, all *there* and greppable.
No need to pull down source packages, you can do audits for uses of things
across the whole installed set of packages at disk speed. That's worth a
*lot*.

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 30, 2009 21:46 UTC (Fri) by mjg59 (subscriber, #23239) [Link]

You can do the same with the Fedora CVS tree without any real trouble. It's not significantly harder
with Debian-derived systems.

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 31, 2009 13:07 UTC (Sat) by tzafrir (subscriber, #11501) [Link] (1 responses)

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 31, 2009 13:54 UTC (Sat) by nix (subscriber, #2304) [Link]

oo, that'll come in very useful. Thank you!

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 30, 2009 21:00 UTC (Fri) by flewellyn (subscriber, #5047) [Link]

I have been a Gentoo user for five years, and most of the Gentoo users I know do view customizability as the reason for using it. I wrote the comment I did based on that experience.

Why you then turned around and talked about speed gains, when I had just said they're not a factor, is beyond me.

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 30, 2009 22:20 UTC (Fri) by rahvin (guest, #16953) [Link]

I disagree completely. I can't comment on why other users use Gentoo but when I used it (and I've had a machine that uses Gentoo for 7 years now that up until a few months ago was my primary router/firewall/dsl modem/general server for my home) was because I could configure anything and the package selection dwarfed any other distribution. I use some rather low user base software on my Gentoo machine because there were ebuilds in the emerge system for them.

Every single software package you can imagine is in their "ports" system. In my experience for small user base software Gentoo is the only distribution that has automatic install packages. When I stopped using it as my primary system (because they were making to many changes for me to keep up with in the unstable branch) they had introduced flags on thousands of packages that would trigger different options. Only want mysql support configured into every package instead of mysql and postgres? There is a flag for that. Don't want QT support in any package? There is a flag for that. The customization ability of Gentoo is unsurpassed. You can ensure packages have support for options and no support for others so users can't use unapproved software because the features won't be compiled in and libraries won't be installed.

Maybe it's not a big deal to have hundreds of different libraries and package options turned on in a generic binary package but the ability to limit that results in smaller binaries and a better system (and hopefully more stable) IMO. God forbid the system ever gets cracked, but I don't want said cracker to have an easy time of it with pre-built support for libraries and packages I don't use. That and the system was very easy to manage as long as you didn't ignore it for 2 years (the reason I dropped it as my primary firewall, that and power considerations). All it takes is to administer is a once a month cron job with "emerge --update world" then logging in the next day and doing "etc-update" to check for configuration changes in the new packages and restarting processes that have updated configurations or altered binaries.

As I said, Gentoo is a system that requires administration time monthly. My new firewall/home server was put in to reduce power costs (it's a mini-itx low power system, actually doesn't have a PSU, just a max 100watt power brick and 12v plug) and I decided to use Debian because it requires a LOT less administration time because they go to extreme effort to reduce or eliminate configuration changes in the stable branch and the stable branch is supported a very long time which is ideal for someone like me that no longer has time to maintain an active system monthly.

Gentoo is the system you want if you want a tightly controlled system. In fact if you run hundreds of systems Gentoo would be easier to manage than most distributions as you can build your own binary "ports" library and ensure each system has only the software it needs with no extra fluff such as unused support for features or other software and no libraries that aren't used. IMO it's all those extra features in binary packages that isn't used that causes system instability (rare) or program's to crash (not so rare). Most distributions compile their packages to support every single feature and cross support for other packages under the sun that 90% of people don't need. Ebuilds are also trivial to make (the reason Gentoo's ebuild library is so large) and explained in a few pages. RPM has 200 page books to explain it and I tried once to understand how it works and failed (put about the same time into it as I did to understand how ebuilds work)

Gentoo has it's uses, people that deride it IMO don't fully understand it's advantages.

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Oct 30, 2009 22:22 UTC (Fri) by marduk (subscriber, #3831) [Link] (3 responses)

You are both right and wrong in some of your comments.

First of all, I pretty much use Gentoo because it's easily customizable. It's easy with Gentoo. Before that I was a Slackware user. I would just install the minimal Slackware and for everything else I'd compile it myself into /usr/local because what Slackware had was either missing, too old or was missing a feature or another or just didn't do what *I* wanted it to. Gentoo gives you more options out-of-the-box but also makes it easy to go beyond what they provide (and not have to wait for someone else to do it for you). But not everyone wants/benefits from this and so obviously Gentoo is not for everyone. But to say there is no benefit or that the benefit isn't used is erroneous.

Secondly I do agree with you that Gentoo *is* kinda like a toy. Some people like to tinker. I'm a tinkerer. For some people a computer is just a utility. For others it's a hobby. I prefer Gentoo because for me Gentoo puts the "fun" back in computing (and Linux especially).

As far as optimizations are concerned, I don't optimize for speed, because I have fast computers and I don't do a lot of things that require a lot of CPU. Memory, however is different. I do use another binary distribution that uses a *lot* more RAM and swaps a heck of a lot more than my similarly configured Gentoo box that's running pretty much the same software. Now I don't know exactly why. I haven't looked into it that much truthfully. But my guess is that the apps in the binary distro is just linked to everything under the sun and it consumes memory, which is a needed "optimization" for me. Especially because I work/test things in virtual machines. But even simple desktop-like stuff takes much more memory. E.g. top shows that console-kit-daemon, which is a root-run daemon, takes up nearly 13x more DATA memory on my binary distro. These are single-user desktops that are similarly configured, but for any given process it uses *much* less memory on Gentoo. It all adds up, and before you know it you are in swapland.

And when other people ask me questions about Gentoo, it's usually of the type "how do I get Gentoo to do X" variety, not "How to I make Gentoo run faster so i can post some benchmark". Most of the things these people want to do are things that would be much more difficult to do in a binary-based distribution, which is what I assume brought them to Gentoo. And, to be honest, a few times I've wonder *why* these people want to do these things, but I guess they're people like me in that they like to have things the way *they* want them and not necessarily the way it was given to them.

As far as the "application" of Gentoo, that seems like you are asking for a business need. I don't have one. But Gentoo isn't about business. It's about individuals.

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Nov 5, 2009 12:35 UTC (Thu) by golding (guest, #32795) [Link] (2 responses)

Ditto, with two additions.

1) I came across Gentoo nearly 9 years ago when I needed some documentation no other distro had. I decided to change to Gentoo on that alone. Documentation in Gentoo is supreme!

2) In time I discovered I could take out all packages and libraries I didn't need or want. I know of of no other distro (except LFS, is that a distro?) where you can remove in total either Java or Emacs. Emacs was the bane of my life, I didn't like it and didn't want it on MY machine. Same with Java. My Gentoo has neither package in any form on it.

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Nov 5, 2009 14:16 UTC (Thu) by anselm (subscriber, #2796) [Link] (1 responses)

The standard installation of Debian GNU/Linux contains neither Java nor Emacs, so there's nothing to remove.

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Nov 5, 2009 18:34 UTC (Thu) by nix (subscriber, #2304) [Link]

Also, both Java and Emacs's problem is that they are insufficiently
integrated into the rest of the system: they're in their own little worlds
and barely realise that Unix is out there. So removing them is relatively
trivial. (Emacs in particular. There are elisp packages that depend on it,
but fundamentally it's for users to interact with, so it's not as if
removing it should lead to half your desktop being zapped because some
critical library depended on Emacs...)

Gentoo Optimizations Benchmarked (Linux Magazine)

Posted Nov 8, 2009 21:22 UTC (Sun) by mrdoghead (guest, #61360) [Link]

Actually, I've only ever heard people cite control and customization as reasons for using Gentoo and never have I seen performance benchmarks given consideration outside the odd magazine article. People who focus on the compilation issue and potential speed benefits in consequence tend to be Gentoo detractors, as it seems to play out again here. For my control-freak part, souce-based distributions are all about control, customization, and exclusion of as much horrifying backdoored and inscrutible and braindead software as possible as easily as it can be done. Gentoo counts among the pioneering projects that aim at giving computer owners a real say in what and how their machines run.


Copyright © 2025, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds