Huge Pages and shmmni

Onload User Guide (UG1586)

Document ID
UG1586
Release Date
2023-07-31
Revision
1.2 English

Users should ensure that the number of system wide shared memory segments (shmmni) exceeds the number of huge pages required.

  • To identify current shmmni setting:
    # cat /proc/sys/kernel/shmmni
  • To set (no reboot required - but not permanent):
    # echo 8000 > /proc/sys/kernel/shmmni
  • To set (permanent - reboot required):
    # echo "kernel.shmmni=8000" >> /etc/sysctl.conf

For example, if 4000 huge pages are required, increase the current shmmni value by 4000.