Change to 64bit kernel

[chris...]

How would I change my kernel to 64bit?
How do I emerge multilib gcc?

[skellr]

You'd need to build the new kernel from a runnning 64 bit system or a live cd.

There is a multilib profile that's helpful for this, although, i haven't gone 32=>64 myself.

[gerard27]

I changed to 64 bit + multilib ~1.5 years ago.
The fastest and best way IMHO is re-install.
If your /home directory is on a separate partition all the better.
Otherwise you'll have to make a backup.
I recommend rescuecd (link in my sig).
Gerard.
_________________
To install Gentoo I use sysrescuecd.Based on Gentoo,has firefox to browse Gentoo docs and mc to browse (and edit) files.
The same disk can be used for 32 and 64 bit installs.
You can follow the Handbook verbatim.
http://www.sysresccd.org/Download

[i92guboj]

There's no standard way (no easy way either) to go from x86 to x86_64. So, re-install.

[chris...]

I used crossdev and now have a 64bit kernel running and 32bit userland

How can I use the multilib profile? Is there a guide anywhere?
I have done it in sparc
http://www.gentoo.org/proj/en/base/sparc/multilib.xml

I consider creating a 64bit chroot, compile a multillib toolchain and putting this in my system as easy
also copy the lib directories to lib32
create lib64
link lib to lib64
add lib32 and lib64 to library path
change CHOST and change the portage profile

from what understand all existing 32bit binaries will use there own libs in lib32, and all new binaries and libraries will be in 64bit

I'm probably missing something or im wrong

[Hu]

[chris...]

[covici]

So, I would like to use my existing kernel, but make it a 64-bit, so my 32-bit system can run while I chroot into my 64-bit system and get everything compiled, copying /etc and /var/lib/portage along the way.

My kernel has x86-32bit set, but I cannot find anywhere to change it to 64-bit.

What am I missing?

[wswartzendruber]

emerge --info

[covici]

[chris...]

OP here

I successfully change to 64bit and didnt like it
32bit is much better

changing back to 32bit was easier then going to 64bit

[covici]

What did you not like about the 64-bit arrangement?

[chris...]

considering i could directly compare it to very similar hardware running the exact same software but in 32bit
the difference i could tell was 64bit used significantly more memory and also utilized less memory

[wswartzendruber]

How does 64-bit use less RAM. Pointers are twice as large.

[Aquous]

[chris...]

less as in less cache and buffers
but more as in more memory less chace and buffers

example to get the point across
64bit
total memory used 75%
memory used less cache and buffers 50%

32bit
total memory used 95%
memory used less cache and buffers 25%