1 files changed, 54 insertions, 0 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index c1b8b3031eb2..8fc0d5aa43b1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3670,10 +3670,64 @@ redo:
         }
 
         if (!ld_moved) {
+                int active_balance;
+
                 schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]);
                 if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
                     !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
                         return -1;
+
+                if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP)
+                        return -1;
+
+                if (sd->nr_balance_failed++ < 2)
+                        return -1;
+
+                /*
+                 * The only task running in a non-idle cpu can be moved to this
+                 * cpu in an attempt to completely freeup the other CPU
+                 * package. The same method used to move task in load_balance()
+                 * have been extended for load_balance_newidle() to speedup
+                 * consolidation at sched_mc=POWERSAVINGS_BALANCE_WAKEUP (2)
+                 *
+                 * The package power saving logic comes from
+                 * find_busiest_group().  If there are no imbalance, then
+                 * f_b_g() will return NULL.  However when sched_mc={1,2} then
+                 * f_b_g() will select a group from which a running task may be
+                 * pulled to this cpu in order to make the other package idle.
+                 * If there is no opportunity to make a package idle and if
+                 * there are no imbalance, then f_b_g() will return NULL and no
+                 * action will be taken in load_balance_newidle().
+                 *
+                 * Under normal task pull operation due to imbalance, there
+                 * will be more than one task in the source run queue and
+                 * move_tasks() will succeed.  ld_moved will be true and this
+                 * active balance code will not be triggered.
+                 */
+
+                /* Lock busiest in correct order while this_rq is held */
+                double_lock_balance(this_rq, busiest);
+
+                /*
+                 * don't kick the migration_thread, if the curr
+                 * task on busiest cpu can't be moved to this_cpu
+                 */
+                if (!cpu_isset(this_cpu, busiest->curr->cpus_allowed)) {
+                        double_unlock_balance(this_rq, busiest);
+                        all_pinned = 1;
+                        return ld_moved;
+                }
+
+                if (!busiest->active_balance) {
+                        busiest->active_balance = 1;
+                        busiest->push_cpu = this_cpu;
+                        active_balance = 1;
+                }
+
+                double_unlock_balance(this_rq, busiest);
+                if (active_balance)
+                        wake_up_process(busiest->migration_thread);
+
         } else
                 sd->nr_balance_failed = 0;