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.

Link: https://lkml.kernel.org/r/20220906194824.2110408-49-Liam.Howlett@oracle.com
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>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0e3e08a093d497319bcc8aef941fa1a6bac946d4..ff49f28391ea380f95a3b3fad8362ee45124984b 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2930,6 +2930,7 @@ 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;
@@ -2986,13 +2987,16 @@ 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;