I know it's a late post but thought it might still be useful ...
Make a bakup of the '.config' file that is generated and remove the 'dot' from the beginning of the name. When/if you do a 'make mrproper' all the files with 'dot' prefixes will be removed. That will allow you to reinvoke the configuration using an existing config file as a base. It will need to be copied to its' original 'dot' format first of course
. Handy, as it is a long configuration at the best of times, but from scratch it's even longer. It's a good idea to go over it a few times too, as there is a lot to consider and by saving that file you can go over the configuration again later or carry it over to further compiles.
will gcc have automatically made use of the extended instruction sets available
I think you must mean cpu features. The default config will be for a Pentium 3 i think, so, depending on what you set the processor type to, flags will be generated by configure for your cpu. You can also manually add things to 'CFLAGS' in the Makefile' . Best not to go to much the rats there, just an '-O2 -march=xxxx -tune=xxx' would do it. But that will basically be automated by the cpu selection anyway.
One thing i think people miss though, if you look at the top of the Makefile, you will see a number of parameters that denote the kernel version. The 4th one ...
is usually left blank, unless the distro has decided to use it, or a maintainer patch has been applied where it will be set with a string to denote the patch. Such as something like ...
EXTRAVERSION = -ck11
You can add to that manually ie;
You end up with a total version string like 2.6.16-ck11-something.
If you append that to the kernel name and the System.map files before copying them over to /boot, you can have multiple compiles of the same kernel available. In case you want to test some option variations,
such as ...
You will need to select 'Y' for 'Local version - append to kernel release' in the 'General setup' config branch at the top of the config tree to get the mapping..
I don't think the auto install covers that though, ( 'make install' )