# vmm - [Command Function](#section445335110416) - [Syntax](#section1795712553416) - [Parameters](#section92544592410) - [Usage](#section104151141252) - [Example](#section11545171957) - [Output](#section075617368542) ## Command Function This command is used to query the virtual memory usage of a process. ## Syntax vmm \[_-a / -h / --help_\] vmm \[_pid_\] ## Parameters **Table 1** Parameter description

Parameter	Description	Value Range
-a	Displays the virtual memory usage of all processes.	N/A
-h \| --help	Displays help information.	N/A
pid	Specifies the ID of the process to query.	[0,63]

## Usage By default, the virtual memory usage of all processes is displayed. ## Example Run **vmm 3**. ## Output **Figure 1** Virtual memory usage of the process with PID 3 ![](figure/virtual-memory-usage-of-the-process-with-pid-3.png "virtual-memory-usage-of-the-process-with-pid-3") **Table 2** Basic process information

Parameter	Description
PID	Process ID
aspace	Address of the virtual memory control block
name	Process name
base	Start address of the virtual memory
size	Size of virtual memory
pages	Number of used physical pages

**Table 3** Virtual memory region information

Output	Description
region	Address of the control block in the virtual memory region
name	Name of the virtual memory region
base	Start address of the virtual memory region
size	Size of the virtual memory region
mmu_flags	MMU mapping attribute of the virtual memory region
pages	Number of used physical pages, including that of the shared memory
pg/ref	Number of used physical pages