vbrummond wrote:I never saw any performance benefit to use make localmodconfig. All it does is detect what modules your system is currently using and disable all (except what you need) of the options (already) marked as a kernel module. So basically it makes your kernel into a monolithic binary. It might save some space or compile time; However if you ever add a new piece of hardware that requires a missing module you will need to recompile a new kernel.
That's all that it does. But the point is to start there, so you won't have to spend 2 hours building the kernel, and have 100+ MB used for the kernel.
Since it only disables modules, you can reconfigure the sources later to re-enable a driver, make modules, and install the modules (I've done this at least a couple times, it's not just speculation).
Then you do the tuning:
check if you need ISA (lspci|grep ISA)--some boards use it for odd purposes;
disable MCA (you almost certainly don't need it);
tune for the lowest CPU you'll use (eg, i586, i686, k{6,7,8}, Core whatever...); select your general options; etc.
If you messed up, you wasted maybe 1-2 hours, not 4-6 hours like you might otherwise.
If you're paranoid about "What if I end up needing to test a DEC network card or find an MGA card for a spare console
on my desktop, or get given some Infiniband card?", it's not for you. But otherwise, you can add back the useful stuff faster than you'd remove anything.