diff options
| -rw-r--r-- | kernel/sched/fair.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 4c400d79f1e5..db45b3554682 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5700,9 +5700,15 @@ wake_affine_idle(int this_cpu, int prev_cpu, int sync) * context. Only allow the move if cache is shared. Otherwise an * interrupt intensive workload could force all tasks onto one * node depending on the IO topology or IRQ affinity settings. + * + * If the prev_cpu is idle and cache affine then avoid a migration. + * There is no guarantee that the cache hot data from an interrupt + * is more important than cache hot data on the prev_cpu and from + * a cpufreq perspective, it's better to have higher utilisation + * on one CPU. */ if (idle_cpu(this_cpu) && cpus_share_cache(this_cpu, prev_cpu)) - return this_cpu; + return idle_cpu(prev_cpu) ? prev_cpu : this_cpu; if (sync && cpu_rq(this_cpu)->nr_running == 1) return this_cpu; |