manual:appendix:items:vm.memory.size_params

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manual:appendix:items:vm.memory.size_params [2017/12/20 12:48]
martins-v more details about 'available' and 'used' parameter calculation
manual:appendix:items:vm.memory.size_params [2019/02/25 08:43]
martins-v 'cached' is also counted into available for linux <3.14
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 ^ Platform ^ **"​available"​** ^ **"​used"​** ^ ^ Platform ^ **"​available"​** ^ **"​used"​** ^
-|//Win32// ​      ​|free |total - free  | +|//AIX//         |free + cached |real memory in use|
-|//​Solaris// ​    ​|free |total - free  | +
-|//OSX//         |inactive + free |active + wired  | +
-|//​OpenBSD// ​    ​|inactive + free + cached |active + wired  | +
-|//​NetBSD// ​     |inactive + execpages + file + free |total - free  ​|+
 |//​FreeBSD// ​    ​|inactive + cached + free |active + wired + cached ​ | |//​FreeBSD// ​    ​|inactive + cached + free |active + wired + cached ​ |
-|//​Linux<​3.14//​ |free + buffers |total - free  | 
-|//Linux 3.14+// |/​proc/​meminfo,​ "​Cached":​+"​MemAvailable:"​ |total - free  | 
 |//HP UX//       ​|free |total - free  | |//HP UX//       ​|free |total - free  |
-|//AIX//         ​|free + cached |real memory in use|+|//Linux<​3.14//  |free + buffers ​+ cached |total - free  | 
 +|//Linux 3.14+// |/​proc/​meminfo,​ "​Cached":​+"​MemAvailable:"​ |total - free  | 
 +|//​NetBSD// ​     |inactive + execpages + file + free |total - free  | 
 +|//​OpenBSD// ​    ​|inactive + free + cached |active + wired  | 
 +|//​OSX// ​        ​|inactive + free |active + wired  | 
 +|//​Solaris// ​    ​|free |total - free  | 
 +|//​Win32// ​      ​|free |total - free  ​|
  
 <note important>​The sum of //​vm.memory.size[used]//​ and //​vm.memory.size[available]//​ does not necessarily equal total. For instance, on FreeBSD:\\ * Active, inactive, wired, cached memories are considered used, because they store some useful information.\\ * At the same time inactive, cached, free memories are considered available, because these kinds of memories can be given instantly to processes that request more memory.\\ \\ So inactive memory is both used and available simultaneously. Because of this, the //​vm.memory.size[used]//​ item is designed for informational purposes only, while //​vm.memory.size[available]//​ is designed to be used in triggers.</​note>​ <note important>​The sum of //​vm.memory.size[used]//​ and //​vm.memory.size[available]//​ does not necessarily equal total. For instance, on FreeBSD:\\ * Active, inactive, wired, cached memories are considered used, because they store some useful information.\\ * At the same time inactive, cached, free memories are considered available, because these kinds of memories can be given instantly to processes that request more memory.\\ \\ So inactive memory is both used and available simultaneously. Because of this, the //​vm.memory.size[used]//​ item is designed for informational purposes only, while //​vm.memory.size[available]//​ is designed to be used in triggers.</​note>​