BOOLEAN GetRtVirtualMemoryInfo(
    RTHANDLE hProcOrVseg , 
    LPVIRTUAL_MEMORY_INFO pMemoryInfo
);

typedef struct tagVirtMemInfo {
    RTHANDLE  hProcess;           // handle for process which owns the vseg
    RTHANDLE  hVseg;              // vseg being inspected
    DWORD     cbVsegSize;         // vseg size, in bytes. 0 == 4 GiB
    DWORD     cbAllocated;        // space allocated from vseg, in bytes
    DWORD     cbAvailable;        // space available, in bytes
    DWORD     cbLargestAvailable; // largest available piece, in bytes
} VIRTUAL_MEMORY_INFO, *LPVIRTUAL_MEMORY_INFO;

hProcOrVseg

A handle for a process or a VSEG. If a process handle is given then the call returns information for that' process VSEG.

pMemoryInfo

A pointer to a VIRTUAL_MEMORY_INFO structure where the information is to be returned.