patches/sched-__set_cpus_allowed_ptr-Check-cpus_mask-not-cpu.patch

From: Scott Wood <swood@redhat.com>
Date: Sat, 27 Jul 2019 00:56:32 -0500
Subject: [PATCH] sched: __set_cpus_allowed_ptr(): Check cpus_mask, not
 cpus_ptr

This function is concerned with the long-term cpu mask, not the
transitory mask the task might have while migrate disabled.  Before
this patch, if a task was migrate disabled at the time
__set_cpus_allowed_ptr() was called, and the new mask happened to be
equal to the cpu that the task was running on, then the mask update
would be lost.

Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/sched/core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1644,7 +1644,7 @@ static int __set_cpus_allowed_ptr(struct
 		goto out;
 	}
 
-	if (cpumask_equal(p->cpus_ptr, new_mask))
+	if (cpumask_equal(&p->cpus_mask, new_mask))
 		goto out;
 
 	dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask);