Using lgrp_init()

The lgrp_init() function initializes the lgroup interface and takes a snapshot of the lgroup hierarchy.

#include <sys/lgrp_user.h>
lgrp_cookie_t lgrp_init(lgrp_view_t view);

When the lgrp_init() function is called with LGRP_VIEW_CALLER as the view, the function returns a snapshot with the resources available only to the calling thread. When the lgrp_init() function is called with LGRP_VIEW_OS as the view, the function returns a snapshot with the resources available to the operating system. When a thread successfully calls the lgrp_init() function, the function returns a cookie that is used by any function interacting with the lgroup hierarchy. When a thread no longer needs the lgroup hierarchy, call the lgrp_fini() function with the cookie as the argument.

The lgroup hierarchy consists of a root lgroup that contains all of the system's CPU and memory resources. The root lgroup might contain other locality groups bounded by smaller latencies.

The lgrp_init() function can return two errors. When a view is invalid, the function returns EINVAL. When there is insufficient memory to allocate the snapshot of the lgroup hierarchy, the function returns ENOMEM.