Updating the kernel

ecuas · 01-10-2007, 08:06 AM

I am running openSUSE 10.2. I have got the 2.6.18.3 kernel. While checking out xconfig, I came across a section called Processor Type or something along those lines. In the list of options in this section, there is an option for AMD64.
My problem is when I had got this suse distro on the CDs, I had downloaded the 32bit version. Can I select the AMD64 option while compiling the new kernel? I will be replacing the current kernel with this one. Will the older programs run correctly if I do this?
MY config is:

AMD Athlon64 2800+
512 MB ram

Thanks

titopoquito · 01-10-2007, 10:28 AM

Yes, you can change the processor type. I have for example Slackware (32bit) running with an AMD64 processor. Software will be compiled as 32 bit, although I changed it to AMD64, as long as you don't change the flags during configuration/compilation.

ecuas · 01-11-2007, 04:14 AM

Will selectintg AMD64 make any real difference in the performance?

Quote:

Software will be compiled as 32 bit, although I changed it to AMD64, as long as you don't change the flags during configuration/compilation

Which flags do I need to change? IM sorry but im just starting off with this. Also, after I change the flags and everything, will the new kernel will be the same as it is in the 64bit version of openSUSE? Or will I have to replace the current 32bit packages with 64bit ones?

titopoquito · 01-11-2007, 04:43 AM

It should make a difference, but the question is if you can notice it. To be honest I would have to measure times for several tasks -- with my usual tasks I cannot notice much speed gain if any.

Not sure about the flags. On Slackware it seems to be SLKCFLAGS="-O2" for AMD64 and something like SLKCFLAGS="-O2 -march=i486 -mtune=i686" for an i486 compatible but i686 optimized package. But I think this is not the core -- if you take a simple piece of software (for example take the source of a simple library) and do "./configure --help" it tells you about --host --target and --build options of the compiler. See http://www.linuxquestions.org/questi...d.php?t=509739 for this. I guess what you are looking for is cross-compiling. And I think this is not so easy because you will need 64bit libraries as well AFAIK, like building a 64 bit system from scratch

ecuas · 01-11-2007, 08:24 AM

thnks. i think i'll have to leave it alone for a while. just updating the kernel for now.