You should read the compatibility of your application with THP.(transparent huge pages)
How do you find its status
cat /sys/kernel/mm/redhat_transparent_hugepage/enabled grep -i --color huge /proc/meminfo
sudo sysctl -a | grep hugepage
at present you will see cat /sys/kernel/mm/transparent_hugepage/enabled telling it is enabled [always]. Other commands are other ways to see the usage.
How do you modify it?
1. Edit /etc/rc.local or better yet /etc/sysctl.conf . WRT rc.local add
if test -f /sys/kernel/mm/transparent_hugepage/enabled; then
echo never > /sys/kernel/mm/transparent_hugepage/enabled
if test -f /sys/kernel/mm/transparent_hugepage/defrag; then
echo never > /sys/kernel/mm/transparent_hugepage/defrag
2. Add “transparent_hugepage=never” to the kernel boot line in the “/etc/grub.conf” file.
Oracle – does not like THP.
Mongo – does not like THP and prefers 4k pages.
Cassandra – There was a thread on twitter and the google group wrt THP. Looks like suggestion is to disable it.
Hadoop does not like THP.
Splunk does not like THP.
MySql does not like THP.
Postgres does not like THP.
What does it do – here are the details.