summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--kernel/sched.c57
1 files changed, 32 insertions, 25 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index b597b07e7911..5ae3568eed0b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1016,38 +1016,45 @@ static int try_to_wake_up(task_t * p, unsigned int state, int sync)
int idx = this_sd->wake_idx;
unsigned int imbalance;
+ imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
+
load = source_load(cpu, idx);
this_load = target_load(this_cpu, idx);
- /*
- * If sync wakeup then subtract the (maximum possible) effect of
- * the currently running task from the load of the current CPU:
- */
- if (sync)
- this_load -= SCHED_LOAD_SCALE;
-
- /* Don't pull the task off an idle CPU to a busy one */
- if (load < SCHED_LOAD_SCALE/2 && this_load > SCHED_LOAD_SCALE/2)
- goto out_set_cpu;
-
new_cpu = this_cpu; /* Wake to this CPU if we can */
- if ((this_sd->flags & SD_WAKE_AFFINE) &&
- !task_hot(p, rq->timestamp_last_tick, this_sd)) {
- /*
- * This domain has SD_WAKE_AFFINE and p is cache cold
- * in this domain.
- */
- schedstat_inc(this_sd, ttwu_move_affine);
- goto out_set_cpu;
- } else if ((this_sd->flags & SD_WAKE_BALANCE) &&
- imbalance*this_load <= 100*load) {
+ if (this_sd->flags & SD_WAKE_AFFINE) {
+ unsigned long tl = this_load;
/*
- * This domain has SD_WAKE_BALANCE and there is
- * an imbalance.
+ * If sync wakeup then subtract the (maximum possible)
+ * effect of the currently running task from the load
+ * of the current CPU:
*/
- schedstat_inc(this_sd, ttwu_move_balance);
- goto out_set_cpu;
+ if (sync)
+ tl -= SCHED_LOAD_SCALE;
+
+ if ((tl <= load &&
+ tl + target_load(cpu, idx) <= SCHED_LOAD_SCALE) ||
+ 100*(tl + SCHED_LOAD_SCALE) <= imbalance*load) {
+ /*
+ * This domain has SD_WAKE_AFFINE and
+ * p is cache cold in this domain, and
+ * there is no bad imbalance.
+ */
+ schedstat_inc(this_sd, ttwu_move_affine);
+ goto out_set_cpu;
+ }
+ }
+
+ /*
+ * Start passive balancing when half the imbalance_pct
+ * limit is reached.
+ */
+ if (this_sd->flags & SD_WAKE_BALANCE) {
+ if (imbalance*this_load <= 100*load) {
+ schedstat_inc(this_sd, ttwu_move_balance);
+ goto out_set_cpu;
+ }
}
}