[PATCH v5 5/5] cpusets: Remove/update outdated comments

["Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>]

cpuset_track_online_cpus() is no longer present. So remove the
outdated comment and replace it with reference to cpuset_update_active_cpus()
which is its equivalent.

Also, we don't lack memory hot-unplug anymore. And David Rientjes pointed
out how it is dealt with. So update that comment as well.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
---

 kernel/cpuset.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e44db78..89ff649 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2046,9 +2046,8 @@ static struct cpuset *cpuset_next(struct list_head *queue)
  * before dropping down to the next.  It always processes a node before
  * any of its children.
  *
- * For now, since we lack memory hot unplug, we'll never see a cpuset
- * that has tasks along with an empty 'mems'.  But if we did see such
- * a cpuset, we'd handle it just like we do if its 'cpus' was empty.
+ * In the case of memory hot-unplug, it will remove nodes from N_HIGH_MEMORY
+ * if all present pages from a node are offlined.
  */
 static void
 scan_cpusets_upon_hotplug(struct cpuset *root, enum hotplug_event event)
@@ -2171,7 +2170,7 @@ void cpuset_update_active_cpus(bool cpu_online)
 /*
  * Keep top_cpuset.mems_allowed tracking node_states[N_HIGH_MEMORY].
  * Call this routine anytime after node_states[N_HIGH_MEMORY] changes.
- * See also the previous routine cpuset_track_online_cpus().
+ * See cpuset_update_active_cpus() for CPU hotplug handling.
  */
 static int cpuset_track_online_nodes(struct notifier_block *self,
 				unsigned long action, void *arg)