Transparent HugePages

RHEL6, OL6 SUSE 11 and UEK2 kernel 부터 해당

 

Disabling Transparent HugePages

Transparent HugePages 설정으로 인해 메모리가 동적 할당되어 메모리할당에 되려 delay 를 주어 성능에 영향을 미칠수 있으므로 오라클에서는 disable 권고함.

 

확인방법 :

 

RHEL kernel

cat /sys/kernel/mm/redhat_transparent_hugepage/enabled

 

다른 kernel

cat /sys/kernel/mm/transparent_hugepage/enabled

결과 :  3가지 값중 always 에 괄호가 쳐져 있으면 enable 되어있는 것임.

 

[always] madvise never

 

조치방법 : 붉은색 라인 추가

 

vi /etc/grub.conf (RHEL7.2인 경우 /boot/grub2/grub.cfg)

 

[root:/root]#vi /etc/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/cciss/c0d0p5
#          initrd /initrd-[generic-]version.img
#boot=/dev/cciss/c0d0
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.32-573.26.1.el6.x86_64)
        root (hd0,0)
        kernel /vmlinuz-2.6.32-573.26.1.el6.x86_64 ro root=UUID=aa061763-d563-4ba1-b0bf-af05357dd7aa rd_NO_LUKS rd_NO_LVM  LANG=en_US.UTF-        8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb  

        quiet  transparent_hugepage=never
        initrd /initramfs-2.6.32-573.26.1.el6.x86_64.img

 

추가후 리부팅..

부팅후에

 

cat /sys/kernel/mm/transparent_hugepage/enabled

always madvise [never]

 

 

cat /proc/meminfo

 

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