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;