On 11/28/23 11:43, Tejun Heo wrote:
On Mon, Nov 27, 2023 at 11:01:22PM -0500, Waiman Long wrote: ...+ * Recursively traverse down the cgroup_rstat_cpu updated tree and push + * parent first before its children into a singly linked list built from + * the tail backward like "pushing" cgroups into a stack. The parent is + * pushed by the caller. The recursion depth is the depth of the current + * updated subtree. + */ +static struct cgroup *cgroup_rstat_push_children(struct cgroup *head, + struct cgroup_rstat_cpu *prstatc, int cpu) +{ + struct cgroup *child, *parent; + struct cgroup_rstat_cpu *crstatc; + + parent = head; + child = prstatc->updated_children; + prstatc->updated_children = parent; + + /* updated_next is parent cgroup terminated */ + while (child != parent) { + child->rstat_flush_next = head; + head = child; + crstatc = cgroup_rstat_cpu(child, cpu); + if (crstatc->updated_children != child) + head = cgroup_rstat_push_children(head, crstatc, cpu); + child = crstatc->updated_next; + crstatc->updated_next = NULL; + } + return head;The recursion bothers me. We don't really have a hard limit on nesting depth. We might need to add another pointer field but can make this iterative, right?
I see. Yes, I think it is possible to make it iterative. Using recursion is just an easier way to do it. Will look into that.
Thanks, Longman
Thanks.
