This tunable controls Transparent Huge Page (THP) aware alignment of ELF loadable segments.
The default value is 0, which preserves the traditional page-sized
alignment for loadable segments.
If set to 1, glibc will attempt to align sufficiently large
PT_LOAD segments to the PMD huge page size when mapping them
with mmap. This increases the likelihood that the kernel can
back these mappings with Transparent Huge Pages.
This tunable has an effect only on systems that support Transparent Huge Pages (currently Linux). On other systems, or if THP is disabled at the kernel level, enabling this tunable has no effect.