What do the various memory states displayed by top mean?
• Active: pages recently statistically used. • Inactive: pages recently statistically unused. • Cache: (most often) pages that have percolated from inactive to a status where they maintain their data, but can often be immediately reused (either with their old association, or reused with a new association.) There can be certain immediate transition from active to ‘cache’ state if the page is known to be clean (unmodified), but that transition is a matter of policy, depending upon the algorithm choice of the VM system maintainer. • Free: pages without data content, and can be immediately used in certain circumstances where cache pages might be ineligible. Free pages can be reused at interrupt or process state. • Wired: pages that are fixed into memory, usually for kernel purposes, but also sometimes for special use in processes. Pages are most often written to disk (sort of a VM sync) when they are in the ‘inactive’ state, but ‘active’ pages can also be synced (but requires the availabil
• Active: pages recently statistically used. • Inactive: pages recently statistically unused. • Cache: (most often) pages that have percolated from inactive to a status where they maintain their data, but can often be immediately reused (either with their old association, or reused with a new association.) There can be certain immediate transitions from active to cache state if the page is known to be clean (unmodified), but that transition is a matter of policy, depending upon the algorithm choice of the VM system maintainer. • Free: pages without data content, and can be immediately used in certain circumstances where cache pages might be ineligible. Free pages can be reused at interrupt or process state. • Wired: pages that are fixed into memory, usually for kernel purposes, but also sometimes for special use in processes. Pages are most often written to disk (sort of a VM sync) when they are in the inactive state, but active pages can also be synced (but requires the availability o
• Active: pages recently statistically used. • Inactive: pages recently statistically unused. • Cache: (most often) pages that have percolated from inactive to a status where they maintain their data, but can often be immediately reused (either with their old association, or reused with a new association.) There can be certain immediate transitions from active to cache state if the page is known to be clean (unmodified), but that transition is a matter of policy, depending upon the algorithm choice of the VM system maintainer. • Free: pages without data content, and can be immediately used in certain circumstances where cache pages might be ineligible. Free pages can be reused at interrupt or process state. • Wired: pages that are fixed into memory, usually for kernel purposes, but also sometimes for special use in processes. Pages are most often written to disk (sort of a VM sync) when they are in the inactive state, but active pages can also be synced. This depends upon the CPU track
• Active: pages recently statistically used. • Inactive: pages recently statistically unused. • Cache: (most often) pages that have percolated from inactive to a status where they maintain their data, but can often be immediately reused (either with their old association, or reused with a new association). There can be certain immediate transitions from active to cache state if the page is known to be clean (unmodified), but that transition is a matter of policy, depending upon the algorithm choice of the VM system maintainer. • Free: pages without data content, and can be immediately used in certain circumstances where cache pages might be ineligible. Free pages can be reused at interrupt or process state. • Wired: pages that are fixed into memory, usually for kernel purposes, but also sometimes for special use in processes. Pages are most often written to disk (sort of a VM sync) when they are in the inactive state, but active pages can also be synced. This depends upon the CPU track
