Question

In Linux Kernel Development, 3rd ed, this code was given for traversing the children of the current process.

list_for_each(list, &current->children) {
    task = list_entry(list, struct task_struct, sibling);
    /* task now points to one of current’s children */
}

The “sibling” in this idiom looks out of place. What is its purpose?

Answer 1

sibling is the name of the list_head structure in struct task_struct that corresponds to the parent’s children list.

That is, in this loop list always points to a sibling member of a struct task_struct, or the children member of the parent.