Linux: Would It Be Worth Moving Toward Gcc 4.0?

[Giniu 0]

Hi to all...wasn't posting some time, becouse of exams... any way - keep introduction short, so...I was wondering about moving toward GCC 4.0 - final release was set to be in two weeks, perhaps also new 2.6.12 kernel would be ready to this time... would it be worth to move toward them now, or still wait and let them became more stable? Does anyone know how would look compatibility for GCC 4.0 with earlier versions of GCC? I know that 3.4.x are slightly uncompatible with 3.3.x... how it looks with 4.0?In month or so I would be moving my box toward something similar to LFS, but I'm working on some modifications so I would be better suited to my needs, so packages and anything aren't borders... I had plan to change system in month, so I would do it anyway - but maybe it is worth to wait for new kernel and gcc? What do you think?

[qwijibow 0]

3.3 and 3.4 sonetimes have *issues*4.0 is anouther world.programs compiled with 3.4 will not work with libraries compiled with 4.0 and vice versa.so if you are planning on re-compileing the whole OS.. (Gentoo or linux from scratch style) then knock yourself out... 4.0 has some prety cool speed anhancing features... (wooo for optimisation)but anything you compile in 4.0 will not work with the current glibc libraries on your distro.

[Giniu 0]

So... you mean that thing compiled with other gcc 3.x won't work with libraries compiled with 4.0 and things compiled with 4.0 won't work with libraries compiled with 3.x... but yes - I'm going to compile whole os... if you say everything would be working if I compile it myself, so decision is made I'm still compiling every single package - never used rpm eventualy sometimes tgz for things that would compile more than few hours... but this is only few hours more... thanks for info qwijibow

[qwijibow 0]

Cool... maybe you should have done some before and after benchmarks, i hear the gcc 4 has some groovy new optimisations.read the GCC 4 man page, maybe you will have to set som new compile flags to take advantages of the new features.

[Giniu 0]

So now just wait for official release - I don't want to let one of key application be taken from CVS just max 16 days before release But how do you think - would kernel 2.6.12 also be released in april, or we would have to wait little more?

[qwijibow 0]

im using kernel 2.6.11 with the gentoo patches, and it working fine for me.i dont think there will be any major differences between 2.6.11 and 2.6.12.gcc 3.x and 4.x are a major version increace, but the new kernel version is just a minor version increace. No securety holes ive heard of, maybe just a few driver updates and stuff.

[Giniu 0]

Probably you are right, but I still don't used to new numbering in kernels... Now I don't know jest what release makes big changes... I know only that when y differs in 2.6.x.y, there are only few small fixes, but I thougth that x would carry something biger... I must look ar release candidate change log... probably there are answers... thanks...

[qwijibow 0]

Linux kernel versions explained :rolleyes:2.6.11-gentoo-r3A.B.C.DA=2B=6C=11D=gentoo-r3A: would be a major huge amasing change, were only on version 2 after almost 15 years.B: is a major change, for example, kernel 2.4 used the OSS driver model for sound (Open Sound System) and version 2.6 Uses ALSA (advanced Linux Sound Architechture)kernel 2.4 is depreciated for 64bit cpu'sand many more things, but the C is only securety fixes, and slight improvements, maybe new device drivers added, that sort of thing. Really, you only need to update the number if you are affected by a bug, or securety hole.ALSO, untill recently, if the B number was an odd number, then it was a testing version.Before kernel 2.6 was realeased, you could use the s.6 testing kernel's (which were 2.5.X)but i think they droped that in favor of just calling testing versions "testing"ALSO, at the end of that number you may see somthing line r11, for example, im using gentoo kernel 2.6.11-gentoo-r3.(wth redhat i think they used the addition "RK" instead of gentoo..)the 2.6.11 part is the basic *vanilla* kernel (vanilla meaning straight from kernel.org without any modifications)the r3 means that this is the 3rd release that gentoo have made of that kernel version.. maybe they tweaked the pathes for performance differently, or removed a bug that a previouse patch has.. who knows.

[Giniu 0]

hehe... quijibow... I knew that... I'm on linux since 2.2 but not long ago Linus changed vanilla kernel names, and current vanilla is 2.6.11.7, while current development is 2.6.12-rc2 this is confusing for me now, since I used to old names style

[qwijibow 0]

, okay sorry.but i still dont understand what is confusing.. "rc" stands for "Release Candidate"most Open Source porgrams use that version scheme.remember firefox 1.0-rc3 then the next version was firefox 1.0

[Giniu 0]

Oh... by the way - I just read what Linus and others said about versions on KernelTrap about the new numbering method... so now I would for sure wait for 2.6.12 - he said that now odd numbers are also aplied to third version number... something like:

2.6.12, 2.6.14, ... would be "stabilizing" releases without many new features... but time to stablilize features that shows up in 2.6.11, 2.6.13, ... also small patches now are inluded into vanilla kernel - fourth number (z in 2.x.y.z) is small patch - without need to update, but usesfull if you are updating from earlier y...

I found it in [this] and[this] article on Kernel Trap...

Also personaly I prefer vanilla kernel since I have bad feelings about patched kerel after working on Debian... especialy now it also has patches included, and there is no need to wait month for new release...

Anyway - thanks for info...

[qwijibow 0]

LOL.... 1 think i like about linux is the humor !

- 2.6.<even>: even at all levels, aim for having had minimally intrusivepatches leading up to it (timeframe: a week or two)

with the odd numbers going like:

- 2.6.<odd>: still a stable kernel, but accept bigger changes leading up
to it (timeframe: a month or two).

- 2.<odd>.x: aim for big changes that may destabilize the kernel for
several releases (timeframe: a year or two)

- <odd>.x.x: Linus went crazy, broke absolutely _everything_, and rewrote
the kernel to be a microkernel using a special message-passing version
of Visual Basic. (timeframe: "we expect that he will be released from
the mental institution in a decade or two").

Lol, visual basic !

so basicaly, its similar to the old way...
i will keep using whatever is the latest version of <even>.<even>.X whenever i re-compilke my kernel.

with an odd 3rd number, i dont think there will by any prblems, and if there are, i can submiot a bug report, and know i helped in my own little almost insignificant way.

ANYWAYS.... when you get your GC 4.0 distro working, let me know how it went, and any porblems you came across, it all sounds quite interesting.

[Giniu 0]

Fianly!! It is finaly there!!! GCC 4.0 was released yesterday... at 20th April 2005 (strange, they placed official release, but doesn't give us news... but it is in stable download so probably everything is ready as it can be for this moment) - first major release since 3.0 (June 18, 2001)!!! I'm gonna test it tommorow evening... as soon as I get it working I would post results

 

There is aslo Kernel 2.6.12-rc3, but they didn't make it with stablilizing 2.6.12... but anyway - while tests like this I probably would like to build whole system second time

[Giniu 0]

damn... I wouldn't be able to build it right now... just before few hours shows up that I wouldn't have time for this in next week... If someone would be able to test it this would be nice - since there isn't any successful build report... I would be nice if it would be posted by someone from Xisto

[MajesticTreeFrog 0]

I understand GCC 4 is a big improvement, with significantly better code optimization