From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 16 Mar 2021 19:59:15 +0000 (-0400)
Subject: sched/fair rcu fix
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=fec821b5e1939d3dc9730b873f0858c9699f93bc;p=users%2Fjedix%2Flinux-maple.git

sched/fair rcu fix

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 73c175206b19..d8674c26e299 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2788,6 +2788,7 @@ static void task_numa_work(struct callback_head *work)
 	if (!mmap_read_trylock(mm))
 		return;
 
+	rcu_read_lock();
 	mas_set(&mas, start);
 	vma = mas_find(&mas, ULONG_MAX);
 	if (!vma) {
@@ -2841,7 +2842,9 @@ static void task_numa_work(struct callback_head *work)
 			if (pages <= 0 || virtpages <= 0)
 				goto out;
 
+			rcu_read_unlock();
 			cond_resched();
+			rcu_read_lock();
 		} while (end != vma->vm_end);
 	}
 
@@ -2856,6 +2859,7 @@ out:
 		mm->numa_scan_offset = start;
 	else
 		reset_ptenuma_scan(p);
+	rcu_read_unlock();
 	mmap_read_unlock(mm);
 
 	/*