Re: [RFC PATCH v3 00/16] Core scheduling v3

[Tim Chen]

On 8/7/19 11:47 PM, Aaron Lu wrote:
> On Tue, Aug 06, 2019 at 02:19:57PM -0700, Tim Chen wrote:
>> +void account_core_idletime(struct task_struct *p, u64 exec)
>> +{
>> +	const struct cpumask *smt_mask;
>> +	struct rq *rq;
>> +	bool force_idle, refill;
>> +	int i, cpu;
>> +
>> +	rq = task_rq(p);
>> +	if (!sched_core_enabled(rq) || !p->core_cookie)
>> +		return;
> 
> I don't see why return here for untagged task. Untagged task can also
> preempt tagged task and force a CPU thread enter idle state.
> Untagged is just another tag to me, unless we want to allow untagged
> task to coschedule with a tagged task.

You are right.  This needs to be fixed.

And the cookie check will also need to be changed in prio_less_fair.

@@ -611,6 +611,17 @@ bool prio_less_fair(struct task_struct *a, struct task_struct *b)
 	 * Normalize the vruntime if tasks are in different cpus.
 	 */
 	if (task_cpu(a) != task_cpu(b)) {
+
+		if (a->core_cookie && b->core_cookie &&
+		    a->core_cookie != b->core_cookie) {

		if (!cookie_match(a, b))

+			/*
+			 * Will be force idling one thread,
+			 * pick the thread that has more allowance.
+			 */
+			return (task_rq(a)->core_idle_allowance <=
+				task_rq(b)->core_idle_allowance) ? true : false;
+		}
+

I'll respin my patches.

Tim