BFS 420: nuke the sticky bits

From: Hillf Danton
Date: Tue May 15 2012 - 09:25:08 EST


Right task could be selected without maitaining the sticky stuff but based on
CPU cache locality.

--- a/kernel/sched/bfs.c Mon May 14 20:50:38 2012
+++ b/kernel/sched/bfs.c Tue May 15 21:12:54 2012
@@ -1095,6 +1095,7 @@ resched_closest_idle(struct rq *rq, int
static inline void
swap_sticky(struct rq *rq, int cpu, struct task_struct *p)
{
+ return;
if (rq->sticky_task) {
if (rq->sticky_task == p) {
p->sticky = true;
@@ -3065,18 +3066,11 @@ task_struct *earliest_deadline_task(stru
continue;

/*
- * Soft affinity happens here by not scheduling a task
- * with its sticky flag set that ran on a different CPU
- * last when the CPU is scaling, or by greatly biasing
- * against its deadline when not, based on cpu cache
- * locality.
+ * Soft affinity happens here by biasing against
+ * deadline when the CPU is scaling, based on CPU
+ * cache locality.
*/
- if (task_sticky(p) && task_rq(p) != rq) {
- if (scaling_rq(rq))
- continue;
- dl = p->deadline << locality_diff(p, rq);
- } else
- dl = p->deadline;
+ dl = p->deadline << (locality_diff(p, rq) + !!scaling_rq(rq));

if (deadline_before(dl, earliest_deadline)) {
earliest_deadline = dl;
--
--
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