This post looks at two debugger commands that can be use to examine memory use, !vm and !memusage. One shows information about virtual memory usage (!vm) and the other one displays information about physical memory use (!memusage). Let’s take a look at each one, beginning with the parameters for !vm: Each of the parameters define a different subset of information that is displayed in the output. !vm takes a single parameter, which is a number representing the desired option flags. Each flag can be enabled by setting a specific bit. This allows fine granularity of the return data. When you add the desired bits together, you get a bitmask that contains only the specific information that you want returned. The default is 0, which displays system-wide virtual memory info and the memory info for each process.
Full Article: Performance Team