linux-kernel - [PATCH v4 47/66] sched: Use maple tree iterator to walk VMAs

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Message-ID: <20211201142918.921493-48-Liam.Howlett@oracle.com>
Date:   Wed, 1 Dec 2021 14:30:11 +0000
From:   Liam Howlett <liam.howlett@...cle.com>
To:     "maple-tree@...ts.infradead.org" <maple-tree@...ts.infradead.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Andrew Morton <akpm@...ux-foundation.org>
CC:     Song Liu <songliubraving@...com>,
        Davidlohr Bueso <dave@...olabs.net>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Laurent Dufour <ldufour@...ux.ibm.com>,
        David Rientjes <rientjes@...gle.com>,
        Axel Rasmussen <axelrasmussen@...gle.com>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Rik van Riel <riel@...riel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Michel Lespinasse <walken.cr@...il.com>,
        Jerome Glisse <jglisse@...hat.com>,
        Minchan Kim <minchan@...gle.com>,
        Joel Fernandes <joelaf@...gle.com>,
        Rom Lemarchand <romlem@...gle.com>,
        Liam Howlett <liam.howlett@...cle.com>
Subject: [PATCH v4 47/66] sched: Use maple tree iterator to walk VMAs

From: "Liam R. Howlett" <Liam.Howlett@...cle.com>

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@...radead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@...cle.com>
---
 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 6e476f6d9435..39bb4a6c8507 100644
--- 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;
-- 
2.30.2