gpgsmsk

Description

The gpgsmsk parameter specifies the mask used to determine if a given page may be swapped. Whenever the pager (vhand) is run, it decrements software reference bits for every active page. When a process subsequently references a page, the counter is reset to the limit (NDREF, as defined in /usr/include/sys/immu.h). When the pager is looking for pages to steal back (if memory is in short supply), it takes only pages whose reference counter has fallen to gpgsmsk or below.

This parameter is specified in /var/sysgen/mtune.

Also see /usr/include/sys/immu.h and /usr/include/sys/tuneable.h and the gpgshi and gpgslo kernel parameters for more information.

Value

Default: 2

Range: 0-7

When to Change

This value is adequate for most systems.

Notes

If the value is greater than 4, pages are written to the swap area earlier than they would be with the default value of gpgsmsk. Thus swapping/paging may occur before it should, unnecessarily using system resources.