RHEL7 hugeadm:WARNING: failed to set pool minimum to 120000 became 87044

Tried to size up hugepage by sysctl but look into meminfo no change:

# sysctl -w vm.nr_hugepages=120000
# grep HugePage /proc/meminfo                 
AnonHugePages:         0 kB
HugePages_Total:   88700
HugePages_Free:     6674
HugePages_Rsvd:     5018
HugePages_Surp:        0

Try with hugeadm, error “failed to set pool”:

# hugeadm --list-all-mounts
# hugeadm --pool-list
# hugeadm --pool-pages-min 2MB:120000
hugeadm:WARNING: failed to set pool minimum to 120000 became 87044

Solution:

Many articles ask for reboot to fix, finally find a way to modify online:

use drop_caches, then modify by hugeadm again, monitor from another session can see HugePage increasing.

# sync; echo 3 > /proc/sys/vm/drop_caches
# hugeadm --pool-pages-min 2MB:120000

$ watch hugeadm --pool-list

Reference:

• https://datahunter.org/hugepages
• https://medium.com/hungys-blog/clear-linux-memory-cache-manually-90bec95ea003