Oracle Audio Technologies B31679-01 User Manual

Page 36

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Oracle TimesTen In-Memory Database Installation Guide

The C development tools are required if native development will be
done on the machine.

Large pages

Large pages can be enabled only if the running Linux kernel supports
large pages (also called “huge pages” in Linux community).

If large pages are supported by the kernel, there should be special files
in the


directory that indicate the number and size of the large


On Linux 2.4.x systems,

the /proc/sys/vm/hugetlb_pool


the total size of the large pages.

On 2.6.x systems, the


file indicates the

total number of large pages.

You can change the total number and size of the large pages by changing
the contents of those files. For example, you can use:

echo "32" > /proc/sys/vm/nr_hugepages

To see the number and size of the allocated large pages use:

cat /proc/meminfo

The following output from this command would indicate that you have
16 large pages, each of the size 256MB for a total of 4GB:

HugePages_Total: 16

HugePages_Free: 16

Hugepagesize: 262144 kB

Note: Since large pages must be allocated on a contiguous memory
space, the actual large page size allocated may be smaller than
requested. Also, the large page size itself is not configurable. The value




indicates the system’s fixed large

page size.

You may need to change the


file if PAM

(Pluggable Authentication Modules) is enabled.

The OS now is ready for the large page support. To enable this feature
on TimesTen, simply set

-linuxLargePageAlignment Size_in_MB

in the daemon options file (



You should specify the large page alignment size in MB, which is the


value in



Once you set up large pages, TimesTen uses as many large pages as
possible. If there are not enough pages, TimesTen uses the normal pages
after consuming all available large pages.