> This should all just be a single boolean flag in the database config telling it to use huge pages which it gets from mmap dynamically. Why is any of the files

> This should all just be a single boolean flag in the database config telling it to use huge pages which it gets from mmap dynamically. Why is any of the filesystem, permission, static allocation malarkey necessary? FWIW, those bits shouldn't be necessary with postgres. If huge_pages is try or on, we'll specify MAP_HUGETLB (or (shift & MAP_HUGE_MASK) << MAP_HUGE_SHIFT if huge_page_size is set). If mmap() fails we'll error (=on) out or fall back to non-huge allocation (=try) However, you do need to allocate huge pages on the system level for this to succeed. But it's indeed just a /proc (or /sys if you want more control). /proc/sys/vm/nr_hugepages, or /sys/kernel/mm/hugepages/hugepages-kB/nr_hugepages. One of the more awkward bits about the kernel config is that they are calculated in pages, so you need to do the conversion yourself :( echo $(( (32 * 1024*1024*1024) / (2 * 1024 * 1024) + 1)) | tee /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages && cat /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages