Transparent Huge Pages (THP) are enabled by default in RHEL 6 for all applications. The kernel attempts to allocate hugepages whenever possible and any Linux process will receive 2MB pages if the mmap region is 2MB naturally aligned. The main kernel address space itself is mapped with hugepages, reducing TLB pressure from kernel code…
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on my demand, i do not need to enable this feature on ES nodes, because it affects to very bad performance and make ES servers hanged. (at that time, CPU consumed 100% and could not reduce the load)
This issue was found by my colleague.

How to disable it?
To disable THP at run time:

# echo never > /sys/kernel/mm/redhat_transparent_hugepage/enabled
# echo never > /sys/kernel/mm/redhat_transparent_hugepage/defrag

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