diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5cbfb3068bc6..3529bf61826b 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2617,11 +2617,32 @@ static void update_scan_period(struct task_struct *p, int new_cpu) int src_nid = cpu_to_node(task_cpu(p)); int dst_nid = cpu_to_node(new_cpu); + if (!static_branch_likely(&sched_numa_balancing)) + return; + if (!p->mm || !p->numa_faults || (p->flags & PF_EXITING)) return; - if (src_nid != dst_nid) - p->numa_scan_period = task_scan_start(p); + if (src_nid == dst_nid) + return; + + /* + * Allow resets if faults have been trapped before one scan + * has completed. This is most likely due to a new task that + * is pulled cross-node due to wakeups or load balancing. + */ + if (p->numa_scan_seq) { + /* + * Avoid scan adjustments if moving to the preferred + * node or if the task was not previously running on + * the preferred node. + */ + if (dst_nid == p->numa_preferred_nid || + (p->numa_preferred_nid != -1 && src_nid != p->numa_preferred_nid)) + return; + } + + p->numa_scan_period = task_scan_start(p); } #else