[PATCH v11 48/69] sched: use maple tree iterator to walk VMAs

[Liam Howlett]

From: "Matthew Wilcox (Oracle)" <willy at infradead.org>

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.

Link: https://lkml.kernel.org/r/20220504011345.662299-33-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220621204632.3370049-49-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy at infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
Acked-by: Vlastimil Babka <vbabka at suse.cz>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: David Howells <dhowells at redhat.com>
Cc: SeongJae Park <sj at kernel.org>
Cc: Will Deacon <will at kernel.org>
Cc: Davidlohr Bueso <dave at stgolabs.net>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
---
 kernel/sched/fair.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 77b2048a9326..e8202b5cd3d5 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2734,6 +2734,7 @@ 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;
@@ -2790,13 +2791,16 @@ 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;
-- 
2.35.1