The plgrp utility can display or set the home lgroup and lgroup affinities for one or more processes, threads, or lightweight processes (LWPs). The system assigns a home lgroup to each thread on creation. When the system allocates a CPU or memory resource to a thread, it searches the lgroup hierarchy from the thread's home lgroup for the nearest available resources to the thread's home.
The system chooses a home lgroup for each thread. The thread's affinity for its home lgroup is initially set to none, or no affinity. When a thread sets an affinity for an lgroup in its processor set that is higher than the thread's affinity for its home lgroup, the system moves the thread to that lgroup. The system does not move threads that are bound to a CPU. The system rehomes a thread to the lgroup in its processor set that has the highest affinity when the thread's affinity for its home lgroup is removed (set to none).
For a full description of the different levels of lgroup affinity and their semantics, see the lgrp_affinity_set(3LGRP) manual page.
The plgrp tool supports the following options:
This option displays the affinities of the processes or threads that you specify for the lgroups in the list.
This option sets the affinity of the processes or threads that you specify for the lgroups in the list. You can use a comma separated list of lgroup/affinity assignments to set several affinities at once.
This option takes control of the target process. This option overrides the control of any other process. See the proc(1) manual page.
This option returns the home lgroup of the processes or threads that you specify. This is the default behavior of the plgrp tool when you do not specify any options.
This option sets the home lgroup of the processes or threads that you specify. This option sets a strong affinity for the listed lgroup. If you specify more than one lgroup, the plgrp utility will attempt to home the threads to the lgroups in a round robin fashion.