Issue with transparent_hugepage/enabled file

I am running RHEL 9.4 with the RT package.

I can't find /sys/kernel/mm/transparent_hugepage/enabled or even /sys/kernel/mm/transparent_hugepage on my system.

When I try and use hugepages by using /sys/devices/system/node/node2/hugepages/hugepages-2048kB/nr_hugepages numastat and /proc/meminfo show the relevant number of pages and pagesize, but I still have a problem allocating the pages from my code.

I'm doing the following

posix_memalign(&buff, 2048x1024, 2048x2048);
madvise(buff, 2048*2048, MADV_HUGEPAGE);

numastat shows the Hugepages_free unchanged.

Any ideas?