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>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d642e9ff28292072157b7f9d99a9b6168389806e..c0c0e691d42656e939985957a1a86b020ac70918 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2929,6 +2929,7 @@ 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;
@@ -2985,13 +2986,16 @@ 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;