The Solaris environment uses a two-handed clock algorithm to look for pages that are candidates for reclaiming when memory is low. The first hand of the clock walks through memory marking pages as unused. The second hand walks through memory some distance after the first hand, checking to see if the page is still marked as unused. If so, the page is subject to reclaim. The distance between the front hand and the back hand is handspreadpages.
1 to maximum number of physical memory pages on the system
Yes. This parameter requires that the kernel variable reset_hands also be set to a non-zero value. Once the new value of handspreadpages has been recognized, reset_hands is set to zero.
Set to lesser of the amount of physical memory and the handspreadpages value
When you want the amount of time that pages are potentially resident before reclaim is increased. Increasing this value increases the separation between the hands, and therefore, the amount of time before a page can be reclaimed.