Do not forget huge pages configuration in kernel - Postgres will use them and it will save a lot of RAM for large databases, esp with many connections.

One of the ways to configure is to continue adding nr_hugepages to kernel, restarting PG and running your workload until you see HugePages_Free growing.

E.g.:

sysctl.d/10-hugepages.conf:vm.nr_hugepages=20000

See how these are used:

[root@potato ~]# cat /proc/meminfo | grep -i huge

AnonHugePages: 4411392 kB

ShmemHugePages: 0 kB

FileHugePages: 0 kB

HugePages_Total: 20000

HugePages_Free: 3103

HugePages_Rsvd: 143

HugePages_Surp: 0

Hugepagesize: 2048 kB Hugetlb: 40960000 kB