Re: [gentoo-user] To x86_64 or not to x86_64

[Alex Schuster]

Anthony E. Caudel wrote:

> I have an AMD 64x2 that I have been using only in x86 mode since I got
> it.  I have been thinking of going to x86_64 mode but I'm wondering if
> it's worth the trouble with multilib, chroot'ing, firefox-bin and other
> compromises (admittedly some minor).  I realize I should see some speed
> increase but probably only in certain areas such as compiling.
>
> So, for those users who have used both, is it worth it overall?

Here are my experiences with amd64, I just helped a friend installing it. 
After reading here we thought it might not be worth the potential trouble, 
but this many registers not being used just feels a little bad. And she 
does mpeg encodings frequently, which is one thing that should work faster.

First peoblem was the minimal Gentoo boot CD. It hang, I think when mounting 
the root FS from the squashfs image on CD. I thought I had a faulty CD-RW 
medium, but a second ttempt with a new CD-ROM gave the same result. But 
there was a kubunto install CD with 64 bit support.

We had trouble with grub. Tab completion did not work, in and outside the 
chroot. I did not dare to install, because there were other disks I did not 
want to endanger. I found and emerged grub-static then, which automatically 
installed into /boot, but something went wrong and grub only showed a GRUB 
message. I installed gurb manually (root (hd0,0), setup (hd0)), and all was 
fine then.
BTW, the manual says that grub-static is only needed when you are on the 
multilib profile. I think I am (/etc/make.profile is 
$PORTDIR/profiles/default-linux/amd64/2007.0(desktop), but emerge --info 
does not show the multilib use flag, which I have defined in make.conf. 
Huh? But it seems that if I were not on multilib, grub would have been 
masked and refused to build.

Next thing I would never have thought of: the root file system was too 
small. I made it 500 MB bis, as /usr, /var, /opt, /tmp and /home are on 
LVM. A little small because of /root/.ccache, but I usually symlink that to 
somewhere else. But why is /lib/modules larger than 300 MB? I would expect 
this to be around 30 MB, which is double the size of these directories on 
my other system, but even ten times more than that? Is something wrong 
here? The installation handbook does not mention this, and also suggest a 
small root partition. The examplee shows 132 MB used there, this looks okay 
to me.

Flash does not work (yet). I emerged netscape-flash and and nspluginwrapper, 
but firefox and konqueror do not have flash working. Did not investigate 
this further yet.

OpenGL works with software rendering only. The card is a Radeon X1550 / 
RV505 and should be supported by the ati-drivers. Module fglrx loads, but 
when starting X, I get this error:

(EE) AIGLX error: dlsym for __driCreateNewScreen_20050727 failed 
(/usr/lib64/dri/fglrx_dri.so: undefined symbol: 
__driCreateNewScreen_20050727)
(EE) AIGLX: reverting to software rendering

I did not find much helpfun information on this yet. One hint is to disable 
Option AIGLX in ServerFlags section of xorg.conf. This gets rid of the 
mesage, and I have "dirent rendering enabled" in the X log file, but 
glrxinfo shows this:
  libGL error: failed to open DRM: Operation not permitted
  libGL error: reverting to (slow) indirect rendering
  display: :0.0  screen: 0
  OpenGL vendor string: Mesa project: www.mesa3d.org
  OpenGL renderer string: Mesa GLX Indirect
  OpenGL version string: 1.4 (1.5 Mesa 6.5.2)

Any ideas on that? We do not want the radeon driver because things like 
multiple displays and tv-out are not working well, I read. I tried anyway, 
I could modprobe radeon, but cannnot start X because a missing device 
section for the 2nd BusID. Maybe I should specify this in xorg.conf (I 
tried a little but to no avail), or get a fresh config instead of one from 
another boot CD. But X -configure does not work. 

X Window System Version 1.3.0
Release Date: 19 April 2007
X Protocol Version 11, Revision 0, Release 1.3
Build Operating System: UNKNOWN
Current Operating System: Linux tanja 2.6.23-gentoo-r9 #9 SMP PREEMPT Mon 
Mar 17 15:14:45 CET 2008 x86_64
Build Date: 16 March 2008
        Before reporting problems, check http://wiki.x.org
        to make sure that you have the latest version.
Module Loader present
Markers: (--) probed, (**) from config file, (==) default setting,
        (++) from command line, (!!) notice, (II) informational,
        (WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Tue Mar 18 22:02:27 2008
List of video drivers:
        radeonhd
        ati
        r128
        atimisc
        fglrx
        radeon
        vesa

Backtrace:
0: X(xf86SigHandler+0x6d) [0x47cd4d]
1: /lib/libc.so.6 [0x2b7db9a29430]
2: /lib/libc.so.6(memcpy+0x46) [0x2b7db9a6e916]
3: /usr/lib64/xorg/modules/drivers//fglrx_drv.so(atiddxProbeMain+0xf1) 
[0x2b7dba934731]
4: X(DoConfigure+0x1f5) [0x47a955]
5: X(InitOutput+0x6a5) [0x468025]
6: X(main+0x275) [0x439d85]
7: /lib/libc.so.6(__libc_start_main+0xf4) [0x2b7db9a16b74]
8: X(FontFileCompleteXLFD+0x229) [0x439259]

Fatal server error:
Caught signal 11.  Server aborting

Aborted


That's it so far. Now compiling {k,open}office. Oh, the /var partition got 
full _again_. Does the install guide mention how HUGE things get on amd64?
	
	Wonko
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