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proc:memory_info_file [2017/04/06 13:04] – peter | proc:memory_info_file [2020/07/15 09:30] (current) – external edit 127.0.0.1 |
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* **Bounce**: Memory used for block device "bounce buffers". | * **Bounce**: Memory used for block device "bounce buffers". |
* **WritebackTmp**: Memory used by FUSE for temporary writeback buffers. | * **WritebackTmp**: Memory used by FUSE for temporary writeback buffers. |
* **CommitLimit**: Based on the overcommit ratio ('vm.overcommit_ratio'), this is the total amount of memory currently available to be allocated on the system. This limit is only adhered to if strict overcommit accounting is enabled (mode 2 in **'vm.overcommit_memory'**). The CommitLimit is calculated with the following formula:\\ \\ | * **CommitLimit**: Based on the overcommit ratio ('vm.overcommit_ratio'), this is the total amount of memory currently available to be allocated on the system. This limit is only adhered to if strict overcommit accounting is enabled (mode 2 in **'vm.overcommit_memory'**). The CommitLimit is calculated with the following formula:\\ |
* CommitLimit = ('vm.overcommit_ratio' * Physical RAM) + Swap\\ \\ | * CommitLimit = ('vm.overcommit_ratio' * Physical RAM) + Swap\\ |
* For example, on a system with 1G of physical RAM and 7G of swap with a `vm.overcommit_ratio` of 30 it would yield a CommitLimit of 7.3G.\\ \\ | * For example, on a system with 1G of physical RAM and 7G of swap with a `vm.overcommit_ratio` of 30 it would yield a CommitLimit of 7.3G.\\ |
* For more details, see the memory overcommit documentation in vm/overcommit-accounting.\\ | * For more details, see the memory overcommit documentation in vm/overcommit-accounting.\\ |
* **Committed_AS**: The amount of memory presently allocated on the system. The committed memory is a sum of all of the memory which has been allocated by processes, even if it has not been "used" by them as of yet. A process which malloc()'s 1G of memory, but only touches 300M of it will only show up as using 300M of memory even if it has the address space allocated for the entire 1G. This 1G is memory which has been "committed" to by the VM and can be used at any time by the allocating application. With strict overcommit enabled on the system (mode 2 in **'vm.overcommit_memory'**), allocations which would exceed the CommitLimit (detailed above) will not be permitted. This is useful if one needs to guarantee that processes will not fail due to lack of memory once that memory has been successfully allocated. | * **Committed_AS**: The amount of memory presently allocated on the system. The committed memory is a sum of all of the memory which has been allocated by processes, even if it has not been "used" by them as of yet. A process which malloc()'s 1G of memory, but only touches 300M of it will only show up as using 300M of memory even if it has the address space allocated for the entire 1G. This 1G is memory which has been "committed" to by the VM and can be used at any time by the allocating application. With strict overcommit enabled on the system (mode 2 in **'vm.overcommit_memory'**), allocations which would exceed the CommitLimit (detailed above) will not be permitted. This is useful if one needs to guarantee that processes will not fail due to lack of memory once that memory has been successfully allocated. |