Huge Pages and shmmni

Onload User Guide (UG1586)

Document ID
Release Date
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.