On 02/09/2018 07:46 AM, Dietmar Eggemann wrote:
On 02/09/2018 01:53 PM, Peter Zijlstra wrote:
On Mon, Jan 29, 2018 at 03:27:09PM -0800, Rohit Jain wrote:
[...]
@@ -6173,8 +6183,15 @@ static int select_idle_cpu(struct task_struct
*p, struct sched_domain *sd, int t
return -1;
if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
continue;
+ if (idle_cpu(cpu)) {
+ if (full_capacity(cpu)) {
+ best_cpu = cpu;
+ break;
+ } else if (capacity_of(cpu) > best_cap) {
+ best_cap = capacity_of(cpu);
+ best_cpu = cpu;
+ }
+ }
No need for the else. And you'll note you're once again inconsistent
with your previous self.
But here I worry about big.little a wee bit. I think we're allowed big
and little cores on the same L3 these days, and you can't directly
compare capacity between them.
Morten / Dietmar, any comments?
Yes, for DynamIQ (big.little successor) systems, those cpus can have
different capacity_orig_of() values already.
OK, given that there are asymmetric capacities in L3 cores, we would
probably have something like the below(?) in select_idle_cpu:
if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
continue;
+ if (idle_cpu(cpu) && !reduced_capacity(cpu))
+ break;
