Problem with transparent huge pages is that it is pushed on applications that were developed with expectation that memory management is based on pages of fixed

Problem with transparent huge pages is that it is pushed on applications that were developed with expectation that memory management is based on pages of fixed size, and now they run on system that reports it uses 4k pages, but sometimes substitutes 2M pages instead of 4k pages, in not-really-transparent manner, causing unexpected memory consumption issues. If default for THP were madvise-only, so THP-aware applications can use it, it would not cause such problems.