HugePage.md

Linux系统采用hugetlbfs的特殊文件系统来加入对2MB和1GB的大页内存的支持

查看CPU是否支持

cat  /proc/cpuinfo |grep --color pse
cat  /proc/cpuinfo |grep --color pdpe1gb

查看内核是否支持

grep  -i hugetlb /boot/config-4.18.0-193.el8.x86_64 
CONFIG_ARCH_WANT_GENERAL_HUGETLB=y
CONFIG_CGROUP_HUGETLB=y
CONFIG_HUGETLBFS=y 
CONFIG_HUGETLB_PAGE=y

大页内存使用情况

# grep Huge /proc/meminfo

AnonHugePages:  12544000 kB
ShmemHugePages:        0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
Hugetlb:               0 kB

NUMA架构的大页内存查看

# cat /sys/devices/system/node/node*/meminfo|fgrep Huge

Node 0 AnonHugePages:    153600 kB
Node 0 HugePages_Total:     0
Node 0 HugePages_Free:      0
Node 0 HugePages_Surp:      0
Node 1 AnonHugePages:     30720 kB
Node 1 HugePages_Total:     0
Node 1 HugePages_Free:      0
Node 1 HugePages_Surp:      0

分配大页内存

//分配2GB大页内存
echo 1024> /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages

//如果是NUMA架构
echo 1024> /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages
echo 1024> /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages

分配超过2GB的大页内存

• 1.安装

yum install libhugetlbfs

• 2.更改启动文件

//修改/etc/grub2.cfg文件
transparent_hugepage=never default_hugepagesz=1G hugepagesz=1G hugepages=4

• 3.挂载

mkdir    /mnt/myhuge
mount -t hugetlbfs nodev /mnt/myhuge