sched: Use maple tree iterator to walk VMAs

The linked list is slower than walking the VMAs using the maple tree.
We can't use the VMA iterator here because it doesn't support
moving to an earlier position.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 6e476f6d94351bd346202c8bb19c1342677dda7b..39bb4a6c8507bf8eeff7cefec95d5f5c22426ad4 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2672,6 +2672,7 @@ static void task_numa_work(struct callback_head *work)
        struct task_struct *p = current;
        struct mm_struct *mm = p->mm;
        u64 runtime = p->se.sum_exec_runtime;
+       MA_STATE(mas, &mm->mm_mt, 0, 0);
        struct vm_area_struct *vma;
        unsigned long start, end;
        unsigned long nr_pte_updates = 0;
@@ -2728,13 +2729,16 @@ static void task_numa_work(struct callback_head *work)
 
        if (!mmap_read_trylock(mm))
                return;
-       vma = find_vma(mm, start);
+       mas_set(&mas, start);
+       vma = mas_find(&mas, ULONG_MAX);
        if (!vma) {
                reset_ptenuma_scan(p);
                start = 0;
-               vma = mm->mmap;
+               mas_set(&mas, start);
+               vma = mas_find(&mas, ULONG_MAX);
        }
-       for (; vma; vma = vma->vm_next) {
+
+       for (; vma; vma = mas_find(&mas, ULONG_MAX)) {
                if (!vma_migratable(vma) || !vma_policy_mof(vma) ||
                        is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) {
                        continue;