1 files changed, 38 insertions, 0 deletions
diff --git a/features/rt/mm-page_alloc-Use-migrate_disable-in-drain_local_pag.patch b/features/rt/mm-page_alloc-Use-migrate_disable-in-drain_local_pag.patch
new file mode 100644
index 00000000..3d068182
--- /dev/null
+++ b/features/rt/mm-page_alloc-Use-migrate_disable-in-drain_local_pag.patch
@@ -0,0 +1,38 @@
+From 6e618c2aeb0d445978c2cbdec84fc15eea6edb82 Mon Sep 17 00:00:00 2001
+From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+Date: Thu, 2 Jul 2020 14:27:23 +0200
+Subject: [PATCH 110/191] mm: page_alloc: Use migrate_disable() in
+ drain_local_pages_wq()
+
+drain_local_pages_wq() disables preemption to avoid CPU migration during
+CPU hotplug and can't use cpus_read_lock().
+
+Using migrate_disable() works here, too. The scheduler won't take the
+CPU offline until the task left the migrate-disable section.
+
+Use migrate_disable() in drain_local_pages_wq().
+
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ mm/page_alloc.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/mm/page_alloc.c b/mm/page_alloc.c
+index cfc72873961d..db713dd3e08e 100644
+--- a/mm/page_alloc.c
++++ b/mm/page_alloc.c
+@@ -3038,9 +3038,9 @@ static void drain_local_pages_wq(struct work_struct *work)
+ 	 * cpu which is allright but we also have to make sure to not move to
+ 	 * a different one.
+ 	 */
+-	preempt_disable();
++	migrate_disable();
+ 	drain_local_pages(drain->zone);
+-	preempt_enable();
++	migrate_enable();
+ }
+ 
+ /*
+-- 
+2.19.1
+