diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9176f7c588a8..1bfad9f39a2f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2157,7 +2157,7 @@ void task_numa_work(struct callback_head *work) struct vm_area_struct *vma; unsigned long start, end; unsigned long nr_pte_updates = 0; - long pages; + long pages, virtpages; WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work)); @@ -2203,9 +2203,11 @@ void task_numa_work(struct callback_head *work) start = mm->numa_scan_offset; pages = sysctl_numa_balancing_scan_size; pages <<= 20 - PAGE_SHIFT; /* MB in pages */ + virtpages = pages * 8; /* Scan up to this much virtual space */ if (!pages) return; + down_read(&mm->mmap_sem); vma = find_vma(mm, start); if (!vma) { @@ -2240,18 +2242,22 @@ void task_numa_work(struct callback_head *work) start = max(start, vma->vm_start); end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE); end = min(end, vma->vm_end); - nr_pte_updates += change_prot_numa(vma, start, end); + nr_pte_updates = change_prot_numa(vma, start, end); /* - * Scan sysctl_numa_balancing_scan_size but ensure that - * at least one PTE is updated so that unused virtual - * address space is quickly skipped. + * Try to scan sysctl_numa_balancing_size worth of + * hpages that have at least one present PTE that + * is not already pte-numa. If the VMA contains + * areas that are unused or already full of prot_numa + * PTEs, scan up to virtpages, to skip through those + * areas faster. */ if (nr_pte_updates) pages -= (end - start) >> PAGE_SHIFT; + virtpages -= (end - start) >> PAGE_SHIFT; start = end; - if (pages <= 0) + if (pages <= 0 || virtpages <= 0) goto out; cond_resched();