[PATCH v7 49/70] sched: Use maple tree iterator to walk VMAs

Liam Howlett
2022-04-04T14:43:33Z

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>
---
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 d4bd299d67ab..b8b7962b5832 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2722,6 +2722,7 @@ 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;
@@ -2778,13 +2779,16 @@ 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;
--
2.34.1