How to disable THP on Centos 7 for mongodb

Question

I just installed a fresh instance of a Centos 7

Linux version 3.10.0-229.1.2.el7.x86_64 (builder@kbuilder.dev.centos.org) (gcc version 4.8.2 20140120 (Red Hat 4.8.2-16) (GCC) ) #1 SMP Fri Mar 27 03:04:26 UTC 2015

I installed a mongodb 3.0 and when I connect I have this weird message:

2015-04-15T07:48:55.583+0000 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2015-04-15T07:48:55.583+0000 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2015-04-15T07:48:55.583+0000 I CONTROL  [initandlisten]
2015-04-15T07:48:55.583+0000 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2015-04-15T07:48:55.583+0000 I CONTROL  [initandlisten] **        We suggest setting it to 'never'

How do I disable THP for this version?

Things I tried without luck

I can disable it running this command:

echo never > /sys/kernel/mm/transparent_hugepage/enabled
echo never > /sys/kernel/mm/transparent_hugepage/defrag

But when I reboot the problem appears again.

I tried to modify /etc/rc.local adding those lines:

if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
  echo never > /sys/kernel/mm/transparent_hugepage/defrag
fi
if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
  echo never > /sys/kernel/mm/transparent_hugepage/enabled
fi
exit 0

made a reboot and no results

I also tried to modify /etc/default/grub ...

Answer 1

I had the same issue, and solved it by writing this in /etc/rc.local :

echo never > /sys/kernel/mm/transparent_hugepage/enabled;
echo never > /sys/kernel/mm/transparent_hugepage/defrag;

I also gave execution permissions to /etc/rc.d/rc.local

Now thb are disabled every time I boot.