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Difference between revisions of "Large Memory Pages"
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Large Page Support | Also known as '''Large Page Support'''. | ||
Normally memory pages are allocated in 4KB chunks, with large pages (or HugeTLB pages in Unix), memory is allocated in 2MB chunks. This allows for more efficient (greater performance) | |||
Normally memory pages are allocated in 4KB chunks, with large pages (or HugeTLB pages in Unix), memory is allocated in 2MB chunks. This allows for more efficient working (and so greater performance) of applications that use large amounts of memory. This is commonly seen in memory intensive applications such as databases and Java. Which can generate a large number of [[Acronyms#T|TLB]] misses due to the large range of memory addresses that they may need to access. Support for large pages generally needs to be enabled on both the OS and application. | |||
General memory background info http://en.wikipedia.org/wiki/Page_(computer_memory) | General memory background info http://en.wikipedia.org/wiki/Page_(computer_memory) | ||
== VMware ESX == | == VMware ESX == | ||
VM's with large pages are supported by default since ESX 3.5. However large pages can't be shared between VM's which means that VM's utilising large pages may need to be backed by more physical RAM than if | VM's with large pages are supported by default since ESX 3.5. However large pages can't be shared between VM's using transparent page sharing, which means that VM's utilising large pages may need to be backed by more physical RAM than if they weren't using large pages. | ||
See http://www.vmware.com/files/pdf/large_pg_performance.pdf for further info. | See http://www.vmware.com/files/pdf/large_pg_performance.pdf for further info. | ||