diff -u: What's New in Kernel Development

It sure would speed up building kernels at home.

?? Really? Code is code. The only difference between a kernel module and a built-in driver is in the linking. If you want a true speed-up on the build, try distcc/distccd.

You can configure all as modules, using "make allmodconfig", but that will definitely prolong the build process, by building un-needed modules.

Oh, so there is such a switch? Neat, I didn't know that. Thanks, Gus.

One question, would "make allmodconfig" reverse previous selections for built-in things? I'll have to try it and see. What fun!

I have to look up "distcc/distccd", that is something new as well. Not that I care about build time, that's not my purpose.

My ideal would be to have the only things built-in be what is present on my base hardware, and then modules for everything else so that if I plug in a webcam it is recognized, if I plug in a USB headset, keyboard, whatever, it's recognized.

As it is, I get boot messages about missing firmware for both Gig-E and video, even though I have every firmware package I can think of already added. Say la damned vee.

Oh, I just figured out where I said something confusing.

Gus, I didn't mean "speed up builds" as in reduce compile time, I meant "speed up builds" by not having to go through all the new hardware in "make oldconfig" typing "m m m m n y m m m n n y m m ...."

Ok, you want "make localmodconfig" and hope for the best.

"make help | less" for more info. ;-)

Gee, I hope the kernel folks don't mind me downloading the kernel tar file again. This makes three times.

Maybe I'll remember not to delete it this time after I think I'm done with it. :^)

Duplicate

Well, that sure ran faster. I did the "make localmodconfig" (and then set the CPU type) and 3.16.4 built in 20 minutes, instead of more than an hour. Cool! I'll try it later and see what happens.

In the mean time, I'm building with the "make allmodconfig" (and setting CPU type, which defaults to Generic x86-64) and it's thrumming along right now.

Whoever said "Don't try this at home" didn't have Linux.

Ok, just because, the "make allmodconfig" option took 102 minutes to compile and assemble the .deb install packages.

Oh, and file size comparison:

1139586 Oct 7 15:17 linux-firmware-image-3.16.4_1.allmoduletest_amd64.deb 35760 Oct 7 14:20 linux-firmware-image-3.16.4_1.moduletest_amd64.deb 9287850 Oct 7 15:17 linux-headers-3.16.4_1.allmoduletest_amd64.deb 8842182 Oct 7 14:20 linux-headers-3.16.4_1.moduletest_amd64.deb 106293642 Oct 7 15:20 linux-image-3.16.4_1.allmoduletest_amd64.deb 26165860 Oct 7 14:20 linux-image-3.16.4_1.moduletest_amd64.deb

So 106MB install file vs 26MB install file. Interesting test.Thanks, Gus.

Just a note to anyone who might care.

Always keep a working kernel as a backup.

Both "all as modules" and "localmodconfig" created kernels that failed immediately. Crash and burn at start-up.

Since it's an encrypted disk, I expected the "localmodconfig" to work, since it says that all the loaded modules at the present time would be compiled in, but clearly that did not work since it never got to decrypting the crypto-disk (where all the modules are).

Fascinating process.