59 lines
1.6 KiB
Diff
59 lines
1.6 KiB
Diff
From 515dbfcc0ada82f09c173da496b20b9c1bc58d40 Mon Sep 17 00:00:00 2001
|
|
From: Tiejun Chen <tiejun.chen@windriver.com>
|
|
Date: Thu, 7 Nov 2013 10:06:07 +0800
|
|
Subject: [PATCH 282/365] cpu_down: move migrate_enable() back
|
|
|
|
Commit 08c1ab68, "hotplug-use-migrate-disable.patch", intends to
|
|
use migrate_enable()/migrate_disable() to replace that combination
|
|
of preempt_enable() and preempt_disable(), but actually in
|
|
!CONFIG_PREEMPT_RT_FULL case, migrate_enable()/migrate_disable()
|
|
are still equal to preempt_enable()/preempt_disable(). So that
|
|
followed cpu_hotplug_begin()/cpu_unplug_begin(cpu) would go schedule()
|
|
to trigger schedule_debug() like this:
|
|
|
|
_cpu_down()
|
|
|
|
|
+ migrate_disable() = preempt_disable()
|
|
|
|
|
+ cpu_hotplug_begin() or cpu_unplug_begin()
|
|
|
|
|
+ schedule()
|
|
|
|
|
+ __schedule()
|
|
|
|
|
+ preempt_disable();
|
|
|
|
|
+ __schedule_bug() is true!
|
|
|
|
So we should move migrate_enable() as the original scheme.
|
|
|
|
|
|
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
|
|
---
|
|
kernel/cpu.c | 2 +-
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|
|
|
diff --git a/kernel/cpu.c b/kernel/cpu.c
|
|
index 072e296c1c12..f4bb4e76e13f 100644
|
|
--- a/kernel/cpu.c
|
|
+++ b/kernel/cpu.c
|
|
@@ -1337,6 +1337,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
|
|
goto restore_cpus;
|
|
}
|
|
|
|
+ migrate_enable();
|
|
cpu_hotplug_begin();
|
|
ret = cpu_unplug_begin(cpu);
|
|
if (ret) {
|
|
@@ -1384,7 +1385,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
|
|
cpu_unplug_done(cpu);
|
|
out_cancel:
|
|
cpu_hotplug_done();
|
|
- migrate_enable();
|
|
/* This post dead nonsense must die */
|
|
if (!ret && hasdied)
|
|
cpu_notify_nofail(CPU_POST_DEAD, cpu);
|
|
--
|
|
2.28.0
|
|
|