On Dec 31 2007 16:19, Bodo Eggert wrote: >Adrian Bunk wrote: >> >> The only advantage I see is that the kernel image you have to flash >> can be made smaller - with the disadvantage that the running kernel >> is bigger by more than 10%. >> >> If you don't believe me, try it yourself: >> Build all drivers statically into your kernel, and then compare the >> vmlinux sizes with CONFIG_MODULES=n and CONFIG_MODULES=y. > >If you'd aim for a small kernel image, you would build anything as a module >that is not requred for booting. > Yes, there is a tradeoff for both.
Example: 16:30 ichi:../net/802 > l fc.o fc.ko -rw-r--r-- 1 jengelh users 7961 Dec 27 15:19 fc.ko -rw-r--r-- 1 jengelh users 2453 Dec 28 23:58 fc.o (from a recent not-so-complete patch turning CONFIG_FC etc. into =m) If fc was modular, it might save the 2453 bytes off the core kernel image, but adds ~5508 bytes to disk. So one has to pick =y or =m depending on whatever suits his/her situation. But the choice should be _available_. >>>> After all, changing it to a bool will allow us to make the >>>> kernel image for nearly everyone smaller by a few hundred >>>> bytes... >>> >>> I can't see why optionally building it as a module would force us >>> to make the kernel bigger. It may be a little more ugly to >>> support =m, but thats it, isn't it? >> >> On architectures like x86 where __exit code is freed at runtime >> af_unix_exit() makes your kernel image (but not the running kernel) >> bigger. >> >> With CONFIG_MODULES=y the 13 EXPORT_SYMBOL's that only exist for >> the theoretical possibility of CONIG_UNIX=m waste a few hundred >> bytes of memory. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
