[linux sysctl] Disable Transparent Hugepages? #22

New issue

Open

opened 2019-03-21 15:26:09 +01:00 by benpro · 1 comment

benpro commented

2019-03-21 15:26:09 +01:00

Contributor

Issue imported from forge.evolix.org on 2019-03-21 14:26:09

Project: ansible-roles

Issue: 2367

Tracker: Evolution

Status: Nouveau

Author: Benoît S.

Category:

Started at: 2017-12-04 00:00:00

Done ratio: 0

Created at: 2017-12-04 13:58:38

Updated at: 2017-12-04 13:58:50

https://blog.nelhage.com/post/transparent-hugepages/

tl;dr

“Transparent Hugepages” is a Linux kernel feature intended to improve performance by making more efficient use of your processor’s memory-mapping hardware. It is enabled (”enabled=always”) by default in most Linux distributions.

Transparent Hugepages gives some applications a small performance improvement (~ 10% at best, 0-3% more typically), but can cause significant performance problems, or even apparent memory leaks at worst.

To avoid these problems, you should set enabled=madvise on your servers by running

echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/enabled

and setting transparent_hugepage=madvise on your kernel command line (e.g. in /etc/default/grub).

This change will allow applications that are optimized for transparent hugepages to obtain the performance benefits, and prevent the associated problems otherwise.

Read on for more details.e>

> **Issue imported from forge.evolix.org on 2019-03-21 14:26:09** > * Project: ansible-roles > * Issue: 2367 > * Tracker: Evolution > * Status: Nouveau > * Author: Benoît S. > * Category: > * Started at: 2017-12-04 00:00:00 > * Done ratio: 0 > * Created at: 2017-12-04 13:58:38 > * Updated at: 2017-12-04 13:58:50 https://blog.nelhage.com/post/transparent-hugepages/ tl;dr “Transparent Hugepages” is a Linux kernel feature intended to improve performance by making more efficient use of your processor’s memory-mapping hardware. It is enabled (”enabled=always”) by default in most Linux distributions. Transparent Hugepages gives some applications a small performance improvement (~ 10% at best, 0-3% more typically), but can cause significant performance problems, or even apparent memory leaks at worst. To avoid these problems, you should set enabled=madvise on your servers by running echo madvise | sudo tee /sys/kernel/mm/transparent_hugepage/enabled and setting transparent_hugepage=madvise on your kernel command line (e.g. in /etc/default/grub). This change will allow applications that are optimized for transparent hugepages to obtain the performance benefits, and prevent the associated problems otherwise. Read on for more details.e>

benpro commented

2019-03-21 15:26:09 +01:00

Author

Contributor