Difference between revisions of "Plugin:Hugepages"

Latest revision as of 14:58, 12 March 2020

The purpose of hugepages plugin is to report the number of free and used huge pages on a system for intelligent workload placement. Huge pages can be used by applications to improve performance such as the memory backing for virtual machines. They are allocated per socket across a platform through configuration files or systemctl. Huge pages help improve the performance of applications by reducing the TLB lookups as the page size is increased from 4KB to 2MB or 1GB. Please note, 1GB huge pages must be configured through grub so they are allocated at boot up time. To collect hugepages information, the following directories are read:

• /sys/devices/system/node/*/hugepages
• /sys/kernel/mm/hugepages

The plugin reads the free_hugepages, surplus and nr_hugepages files under the directories listed above, determines the used pages (nr_hugepages + surplus pages - free_hugepages) and reports the free and used huge pages on a per node level or what’s available across the system (per hugepage size), results are available in terms of:

• The number
• The size in bytes
• The percentage

For a full description of available options please refer to the collectd.conf(5) manual page.

Synopsis

 <Plugin hugepages>
   ReportPerNodeHP  true
   ReportRootHP     true
   ValuesPages      true
   ValuesBytes      false
   ValuesPercentage false
 </Plugin>

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Dependencies

See also

• Plugin:Hugepages/tests
• Hugepages plugin high level design document