26.8. Buildroot rebuild is slow when the root filesystem is large
Buildroot is not designed for large root filesystem images, and the rebuild becomes very slow when we add a large package to it.
This is due mainly to the pkg-generic GLOBAL_INSTRUMENTATION_HOOKS sanitation which go over the entire tree doing complex operations… I no like, in particular check_bin_arch and check_host_rpath
We have applied 983fe7910a73923a4331e7d576a1e93841d53812 to out Buildroot fork which removes part of the pain by not running:
>>> Sanitizing RPATH in target tree
which contributed to a large part of the slowness.
Test how Buildroot deals with many files with:
./build-buildroot \ --config 'BR2_PACKAGE_LKMC_MANY_FILES=y' \ -- \ lkmc_many_files-reconfigure \ |& \ ts -i '%.s' \ ; ./build-buildroot |& ts -i '%.s'
and notice how the second build, which does not rebuilt the package at all, still gets stuck in the RPATH check forever without our Buildroot patch.