Ubuntu 5.10 and processor optimizations

[djnes]

I saw a page at one point with some console commands to enable better support and optimizations for specific processors. I'm using a P4 2.4B processor, and was hoping someone had a link to these commands.

 

[Eva_Unit_0]

you're most likely referring to the GCC optimizations (CFLAGS, CXXFLAGS). Those aren't just commands you can pass to magically speed it up...in order to optimize using those you have to recompile the applications. This is the idea behind gentoo (and it's derivatives, rockhopper and etc.) that are source-based distros so that optimizations can be done like that.

 

[Stugots]

I think about all you can do as far as processor optimizations is make sure you're running the correct kernel for you processor. In your case youd need the 686 kernel, you may be running the 386 kernel.

When I had my old laptop with an Athlon XP, I didn't notice much improvement going from the 386 to the K7 kernel.

 

[MorfiusX]

Also, if you read between the Gentoo lines (they no longer support stage 1 or 2 installs), they "optimizations" don't help that much and can easily screw your entire system up.

 

[Deleted member 65081]

Also, if you read between the Gentoo lines (they no longer support stage 1 or 2 installs), they "optimizations" don't help that much and can easily screw your entire system up.

This is entirely inaccurate. Firstly, prcoessor optomization is done by every distro, and unless you enter something wrong or incompatable, is entirely stable. As stable as any other distro, that is. Secondly, optomization is done on many levels, not just a base installation. Meaning, maybe your gnuutils wont be optomized, but perhaps your desktop environment will. Finally, stage 1 and 2 installs are still available, they are simply no lnoger included in the Gentoo Handbook.

I wouldn't be one to say that Gentoo 'optomization' is the key to anything anyhow, I would say it is about configuration.

 

[deuce868]

Ubuntu is debian based so I'm going to assume you can load up a custom kernel-image just like you can in debian. Do this to see available images:

sudo apt-cache search kernel-image | more

That should get you a list of available images and you can look for specific ones. For instance, to get smp working after you install debian you have to then go and install the smp kernel image before it will support the second processor.

 

[MorfiusX]

I wouldn't be one to say that Gentoo 'optomization' is the key to anything anyhow, I would say it is about configuration.

I just remember reading a Gentoo developer blog or something that I read that was talking about how tweaking the CFLAGS and what not usually cause more harm than good, especially when you consider that it only nets a small gain. That was the reason they stopped support the stage 1/2 installs. Maybe I took his opinion for granted, maybe not.

I don't see where it would affect a non-source based distro though seeing that you have to compile the everything from source to get anything out it. I think this would be a pain for a distro that wasn't designed for this.

I guess I am just used to building servers where I'd rather have stability from a distro like Debian with pre-built and tested packages than have a distro like Gentoo with its bleeding-edge/tweaked out/less stabil packages.

 

[eeyrjmr]

I just remember reading a Gentoo developer blog or something that I read that was talking about how tweaking the CFLAGS and what not usually cause more harm than good, especially when you consider that it only nets a small gain. That was the reason they stopped support the stage 1/2 installs. Maybe I took his opinion for granted, maybe not.

I don't see where it would affect a non-source based distro though seeing that you have to compile the everything from source to get anything out it. I think this would be a pain for a distro that wasn't designed for this.

I guess I am just used to building servers where I'd rather have stability from a distro like Debian with pre-built and tested packages than have a distro like Gentoo with its bleeding-edge/tweaked out/less stabil packages.

Well not quite true. The CFLAGS and stuff do make a slight difference
Last time I installed Mandrake and FC they had their binaries optimiesed to i586.

On my Gentoo box my make.conf is (stripped)

jrb@Fluid ~ $ cat /etc/make.conf
# These settings were set by the catalyst build script that automatically built this stage
# Please consult /etc/make.conf.example for a more detailed example


CFLAGS="-O3 -march=pentium4 -fforce-addr -pipe -fomit-frame-pointer"
CHOST="i686-pc-linux-gnu"
CXXFLAGS="${CFLAGS} -fvisibility-inlines-hidden"
ACCEPT_KEYWORDS="x86"
MAKEOPTS="-j2"


USE="..."


INPUT_DEVICES="keyboard mouse"
VIDEO_CARDS="nv nvidia vesa"

...

THIS enabled some extra CPU stuff, that FC and others dont do. Also take the "visibility inline hidden" flag, Firefox actually strips this when it compiles BUT there are patches to re-enable it and it give a loading of page boost.

Playing around with CFLAGS and all that gives you the chance to get that extra couple of percent performance. If you dont want that, then Gentoo isn't for you (1/2 of the fun is fiddling with it, IF I wanted a distro that always worked I would go for Ubuntu/FC, but I like playing with masked packages).


The problem actually comes for software projects. One example I know of is the GAIM project. ABT a year ago there was some serious bad plood between GAIM, Gentoo-DEV's and as a result GEntoo-Users. It got so bad that if you go onto the GAIM IRC channel and even mention you use Gentoo you got kicked.

Why? Well with Gentoo you can enable all these funky GCC flags BUT that does not mean software will compile with it, they might fail due to oversight in code. A particular CFLAG that is common in Gentoo make.conf was I believe the root-cause of the dissagreement. FOr a non-optimised CFLAG most code will compile, start adding the extra optimisation and any slight oversight in the code starts causing the code not to get compiled (quite alot of hte patche in Gentoo are to get around gentoo-ism setup as well as the use of CFLAG that normally break compiling)

long story short, GAIM thought Gentoo-DEV's were calling GAIM-devs shite coders when all they were questioning was why GAIM wouldn't compile with certain CFLAG's when there is no reason for it to fail.


However, the main benefit/optimisation from GEntoo is from its USE flags. Why should I have support for QT compiled into a program when I dont hav eQT installed or dont want it!!! it makes hte binary smaller

 

[unhappy_mage]

http://funroll-loops.org/

 

[Eva_Unit_0]

http://funroll-loops.org/

see, I seriously don't get that site. How is being able to customize your software a bad thing? That site makes fun of the fact that you get to configure USE flags and pick exactly what software you install...and how is that bad? I rather like being able to tell the OS not to install tons of needless software and libraries that I'll never use

The only decent point that site makes is that people who go crazy with like 10 lines of CFLAGS are idiots, but most real gentoo users (like myself and the above posters) don't do that.

True, compiler optimizations don't make a huge difference in the end. But that's not the point of gentoo. The point of gentoo is to customize your packages and only install what you want to, how you want to.

 

[unhappy_mage]

see, I seriously don't get that site. How is being able to customize your software a bad thing? That site makes fun of the fact that you get to configure USE flags and pick exactly what software you install...and how is that bad? I rather like being able to tell the OS not to install tons of needless software and libraries that I'll never use

And if you someday need it... you're screwed, please recompile everything. I rather like installing things once and having all the features available

The only decent point that site makes is that people who go crazy with like 10 lines of CFLAGS are idiots, but most real gentoo users (like myself and the above posters) don't do that.

True, compiler optimizations don't make a huge difference in the end. But that's not the point of gentoo. The point of gentoo is to customize your packages and only install what you want to, how you want to.

So why give people the option? It's like leaving a big red button marked "don't press!" in your operating system. I can completely understand where the funny bug reports come from - Gentoo encourages you to add CFLAGS with only a vague disclaimer that "too much optimization can make programs behave bad (sic)". No mention of what "too much optimization" means - two flags? eight flags? - just "don't use too much".

I used Gentoo for six months as my only desktop OS. By the end of the first month, I had everything just the way I wanted. Well, except for dmix in alsa. And the extra buttons on my mouse. And... well, okay, close to the way I wanted. Then I put in another drive, installed Debian, and got to "close" within ten minutes. A tiny bit of editing config files, some gui things that actually worked, and I was there. No longer did updating my system with security fixes, etc, take hours - apt-get update; apt-get upgrade and I was current in minutes. I didn't even need an install manual.

 

[Deleted member 65081]

see, I seriously don't get that site. How is being able to customize your software a bad thing? That site makes fun of the fact that you get to configure USE flags and pick exactly what software you install...and how is that bad? I rather like being able to tell the OS not to install tons of needless software and libraries that I'll never use

The only decent point that site makes is that people who go crazy with like 10 lines of CFLAGS are idiots, but most real gentoo users (like myself and the above posters) don't do that.

True, compiler optimizations don't make a huge difference in the end. But that's not the point of gentoo. The point of gentoo is to customize your packages and only install what you want to, how you want to.

It's a joke for gods sake Still funny every time I see it.

 

[eeyrjmr]

And if you someday need it... you're screwed, please recompile everything. I rather like installing things once and having all the features available

So why give people the option? It's like leaving a big red button marked "don't press!" in your operating system. I can completely understand where the funny bug reports come from - Gentoo encourages you to add CFLAGS with only a vague disclaimer that "too much optimization can make programs behave bad (sic)". No mention of what "too much optimization" means - two flags? eight flags? - just "don't use too much".

I used Gentoo for six months as my only desktop OS. By the end of the first month, I had everything just the way I wanted. Well, except for dmix in alsa. And the extra buttons on my mouse. And... well, okay, close to the way I wanted. Then I put in another drive, installed Debian, and got to "close" within ten minutes. A tiny bit of editing config files, some gui things that actually worked, and I was there. No longer did updating my system with security fixes, etc, take hours - apt-get update; apt-get upgrade and I was current in minutes. I didn't even need an install manual.

All you have shown is Gentoo is not for you, which if fine, at least you have the CHOICE to choose another Distro.

Quite a few of us actually like Gentoo and stick with it, yes what you say is true abt IF you do not include something at one point BUT then require it, you MUST install it, but you have the choice to do that.
For a very long time there were no CD-burning software for GNOME and when I needed a burner (had got along quite happy with just Nautilus burner for data) I was put in a situation of using command-line (fine for me, not for my wifE) or Install QT+K4B, I compiled and added QT to my system

Later a decent burner came available and QT was quickly removed!


Equally w.r.t. that ASSHAT in that bugreport he had a fucked up system. With increase crazyness of CFLAGS there is an increase in the chance that the compiler will break and not just the code!

Like my example with GAIM, that is a coding issue,but these day's it is pretty good with advanced CFLAGS, but if I went crazy the chances or a CFLAG clash with my specific hardware increases.

remember the DEV's have hardware, but their hardware will not be the same as yrs. They can go crazy on CFLAG's and get the code working for that set of CFLAG's but what if they have a AMD processor and you try someting similar on an INTEL, there is no guentee that what worked for them will work for you

HEnce the need in bugreports to have "sane" CFLAGS toat least give the DEV's a chance to track down a potential bug in GCC or the source of the package you are trying


Usual method is to post on forum with your emerge --info and someone will say turn down yr CFLAGS, if the error still occurs, submit a bug since the chances or it being a bug to effect everyone increases as opose to being a one-off, un-reproducable (bugs can only be fixed if they can be reporduced)

 

[unhappy_mage]

Quite a few of us actually like Gentoo and stick with it, yes what you say is true abt IF you do not include something at one point BUT then require it, you MUST install it, but you have the choice to do that.
For a very long time there were no CD-burning software for GNOME and when I needed a burner (had got along quite happy with just Nautilus burner for data) I was put in a situation of using command-line (fine for me, not for my wifE) or Install QT+K4B, I compiled and added QT to my system

That's not what I'm talking about - suppose you had no printer and therefore built everything with "-cups". Later you get a printer and realize your favorite piece of software has cups support, but you turned it off, so you have to rebuild it. The "I can leave pieces out" argument doesn't work for me - I want all the pieces in the first place! Disk space is cheap.

Usual method is to post on forum with your emerge --info and someone will say turn down yr CFLAGS, if the error still occurs, submit a bug since the chances or it being a bug to effect everyone increases as opose to being a one-off, un-reproducable (bugs can only be fixed if they can be reporduced)

With a binary distro, that's one less thing to worry about. You've got the same binary as everyone else, so bug reports are all that much simpler. And if the only way to debug is to "turn down your CFLAGS", why not leave them down all the time? It's not like they help all that much...

 

[unhappy_mage]

heh, rebuilding is cake, "emerge --newuse world" would rebuild everything affected by your new use variables, nothing left to chance in missing a program / dependancy just requires time.

But that's just the point. Why would you want to paint yourself into a corner like that? You say it's "just time", but why would you use CFLAGS unless you're trying to save time in the long run? Why would you turn off options except to speed up loading?