Usage

3.1. To Display Basic System Information

To display basic system information, select the System tab.

In the System tab, information is organized into three groups:

  • System Information
  • Hardware
  • System Status

3.2. To Display the Process List

To display the process list, select the Processes tab.

In the Processes tab, the processes are organized as a table. The rows of the table display information about the processes. The columns represent information fields for the processes, such as the name of the user who owns the process, the amount of memory currently being used by the process, and so on. From left to right, the Processes tab displays the following columns by default:

  • Process Name
  • Status
  • %CPU
  • Nice
  • ID
  • Memory

For information about how to change the columns displayed in the process list, see Section 4.1 ― Processes.

3.2.1. Parent Processes and Child Processes

A parent process is a process that spawns another process. The spawned process is a child process of the original parent process. By default, System Monitor does not show process dependencies. For information about how to change the default display behavior, see Section 3.4.4 ― To Show Dependencies.

3.2.2. Process Priority and Nice Values

Processes run in order of priority: high-priority processes run before low-priority processes. Child processes generally inherit their priority from their parent process.

The priority of a process is set by the nice value of the process, as follows:

  • A nice value of 0 means that the process has normal priority.
  • The higher the nice value, the lower the priority.
  • The lower the nice value, the higher the priority.

For information about how to change the priority of a process, see Section 3.6 ― To Change the Priority of a Process.

3.3. To Sort the Process List

To sort the process list, perform the following steps:

  1. Select the Processes tab to display the process list.
  2. By default, the processes are listed by name, in alphabetical order. To list the processes in reverse alphabetical order, click on the Process Name column header.
  3. Click on any column header to sort the processes by the information in that column, in alphabetical or numerical order.
  4. Click again on the column header to sort the data in reverse alphabetical or reverse numerical order.

3.4. To Modify the Contents of the Process List

You can modify the contents of the process list in several ways.

3.4.1. To Show All Processes

To show all processes in the process list, perform the following steps:

  1. Select the Processes tab to display the process list.
  2. Choose View ▸ All Processes.

3.4.2. To Show Only Processes Owned by the Current User

To show only the processes that are owned by the current user, perform the following steps:

  1. Select the Processes tab to display the process list.
  2. Choose View ▸ My Processes.

3.4.3. To Show Only Active Processes

To show only the active processes in the process list, perform the following steps:

  1. Select the Processes tab to display the process list.
  2. Choose View ▸ Active Processes.

3.4.4. To Show Dependencies

To show process dependencies in the process list, perform the following steps:

  1. Select the Processes tab to display the process list.
  2. Choose View ▸ Dependencies.

If the Dependencies menu item is selected, the processes are listed as follows:

  • Parent processes are indicated by a triangle symbol to the left of the process name. Click on the triangle symbol to show or hide the associated child processes.
  • Child processes are indented, and listed with their parent process.

If the Dependencies menu item is not selected:

  • Parent processes and child processes are not distinguishable.
  • All processes are listed in alphabetical order.

3.5. To Display Memory Maps for a Process

To display memory maps for a process, perform the following steps:

  1. Select the Processes tab to display the process list.
  2. Select the process in the process list.
  3. Choose View ▸ Memory Maps.

The Memory Maps dialog displays the information in tabular format. The name of the process is displayed above the memory-map table. From left to right, the Memory Maps dialog displays the following columns:

Filename

The location of a shared library that is currently used by the process. If this field is blank, the memory information in this row describes memory that is owned by the process whose name is displayed above the memory-map table.

VM Start

The address at which the memory segment begins.

VM End

The address at which the memory segment ends.

VM Size

The size of the memory segment.

Flags

The following flags describe the different types of memory-segment access that the process can have:

p

The memory segment is private to the process, and is not accessible to other processes.

r

The process has permission to read from the memory segment.

s

The memory segment is shared with other processes.

w

The process has permission to write into the memory segment.

x

The process has permission to execute instructions that are contained within the memory segment.

VM Offset

The virtual memory offset of the memory segment.

Device

The major and minor device numbers of the device on which the shared library filename is located.

Inode

The inode on the device from which the shared library location is loaded into memory.

Click on any column header to sort the data by the information in that column, in alphabetical or numerical order. Click again on the column header to sort the data in reverse alphabetical or reverse numerical order.

Click Close to close the Memory Maps dialog.

3.6. To Change the Priority of a Process

To change the priority of a process, perform the following steps:

  1. Select the Processes tab to display the process list.

  2. Select the process for which you want to change the priority.

  3. Choose Edit ▸ Change Priority. The Change Priority dialog is displayed.

  4. Use the slider to set the nice value of the process.

    The nice value sets the priority of the process: the lower the nice value, the higher the priority.

    To specify a nice value lower than zero, non-root users must enter the root password.

  5. Click on the Change Priority button.

3.7. To End a Process

To end a process, perform the following steps:

  1. Select the Processes tab to display the process list.

  2. Select the process that you want to end.

  3. Choose Edit ▸ End Process, or click on the End Process button.

    By default, a confirmation alert is displayed. For information about how to display or hide the confirmation alert, see Section 4.1 ― Processes.

  4. Click on the End Process button to confirm that you want to end the process. System Monitor forces the process to finish normally.

This is the preferred way to stop a process.

3.8. To Terminate a Process

To terminate a process, perform the following steps:

  1. Select the Processes tab to display the process list.

  2. Select the process that you want to terminate.

  3. Choose Edit ▸ Kill Process.

    By default, a confirmation alert is displayed. For information about how to display or hide the confirmation alert, see Section 4.1 ― Processes.

  4. Click on the Kill Process button to confirm that you want to terminate the process. System Monitor forces the process to finish immediately.

You usually terminate a process only if you cannot end the process normally as described in Section 3.7 ― To End a Process.

3.9. To Monitor CPU Usage

To monitor CPU usage, select the Resources tab.

System Monitor displays the CPU usage history in graphical format. Underneath the graph, System Monitor also displays the current CPU usage, as a percentage.

3.10. To Monitor Memory and Swap Usage

To monitor memory and swap usage, select the Resources tab.

System Monitor displays the memory usage history and the swap usage history in graphical format. Underneath the graph, System Monitor also displays the following numerical values:

  • Used memory out of total memory
  • Used swap out of total swap

3.11. To Monitor Network Activity

To monitor network activity, select the Resources tab.

System Monitor displays the network history in graphical format. Underneath the graph, System Monitor also displays the following numerical values:

  • Received data per second and total
  • Sent data per second and total

3.12. To Monitor File Systems

To monitor file systems, select the File Systems tab.

System Monitor displays mounted file systems in tabular format. From left to right, the table displays the following columns:

Device

Location of block file

Directory

Mount point (directory to access) of device

Type

File system type

Total

Total capacity

Free

Amount of space not in use

Available

Amount of space which can be used

Used

Amount of space which is used (and percentage of Total)