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1GB Hugepage Support On X86_64 HVM Guest With UEK3 Running Over OVM 3.3 Server (Doc ID 1670223.1)

Last updated on AUGUST 04, 2018

Applies to:

Oracle VM - Version 3.2.8 and later
Linux x86-64

Symptoms

Oracle UEK3 kernel support 1GB hugepage size, but HVM guest installed latest UEK3 fail to recognize 1GB hugepage, only 2MB huagepage size is allocated.

Pre-condition: hugepage options already been set into grub.conf

# cat /proc/cmdline
ro root=LABEL=/ default_hugepagesz=1G hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=100 SYSFONT=latarcyrheb-sun16 LANG=en_US.UTF-8 KEYTABLE=us

1) dmesg shows only 2MB page size

# dmesg | grep -i huge
Command line: ro root=LABEL=/ default_hugepagesz=1G hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=100 SYSFONT=latarcyrheb-sun16 LANG=en_US.UTF-8 KEYTABLE=us
Kernel command line: ro root=LABEL=/ default_hugepagesz=1G hugepagesz=1G hugepages=2 hugepagesz=2M hugepages=100 SYSFONT=latarcyrheb-sun16 LANG=en_US.UTF-8 KEYTABLE=us
hugepagesz: Unsupported page size 1024 M
Initializing cgroup subsys hugetlb
HugeTLB registered 2 MB page size, pre-allocated 2 pages

2) meminfo shows only 2MB page size

# cat /proc/meminfo | grep -i huge
HugePages_Total: 2
HugePages_Free: 2
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB

3) cpuinfo shows no pdpe1gb flag

# cat /proc/cpuinfo | grep -i 1GB

 

Cause

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In this Document
Symptoms
Cause
Solution
References

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