Question

Using one of the referenced website articles or an article of your choice, discuss the latest advances in memory management to include the use of tables and memory swapping from memory to disk.

Answer 1

The memory manager handles the allocation and management of physical and virtual memory for the operating system. The following are the most important services that it provides:+

• Managing key system resources, such as the paged and nonpaged memory pools and system cache.
• Mapping the VA space into physical memory.
• Paging.
• Protecting the address space of processes from each other and from the operating system itself

According to Microsoft, latest advanced memory management uses,

Cache-Aligned Pool Allocation

Windows implements support for cache-aligned pool allocation. Drivers can specify the following flags in the ExAllocatePoolXxx functions to request cache-aligned memory:

1. NonPagedPoolCacheAligned
2. PagedPoolCacheAligned

Load Balancing

Windows exports the following new events to help in load balancing:

• LowCommitConditionNotification
• HighCommitConditionNotification
• MaximumCommitConditionNotification

The LowCommitConditionNotification event is set when the operating system's commit charge is low, relative to the current commit limit. In other words, memory usage is low and a lot of space is available for allocations.

The HighCommitConditionNotification event is set when the operating system's commit charge is high, relative to the current commit limit. In other words, memory usage is high and very little space is available. If adequate disk space is available, the system obtains more memory by automatically increasing the page file size up to the limit imposed by the administrator. A short-term option is to reduce the current system load. Long-term solutions are to increase the minimum page file size or add RAM.

The MaximumCommitConditionNotification event is set when the operating system's commit charge. In other words, memory usage is very high, very little space is available, and the system cannot increase the size of its paging files because of the current limits imposed by the administrator. A system administrator can always increase the size or number of paging files, without restarting the computer, if adequate disk space is available. Other alternatives are to increase the minimum or maximum page file sizes, add RAM, or reduce the load.