diff options
| author | Tiejun Chen <tiejun.chen@windriver.com> | 2013-11-07 10:06:07 +0800 |
|---|---|---|
| committer | Gary S. Robertson <gary.robertson@linaro.org> | 2014-05-07 08:56:19 -0500 |
| commit | 0f09657baf26d40f23beace1b2399e0239555b41 (patch) | |
| tree | 30a7489219140ee27594422ccab8670286b4875b | |
| parent | 9b4a5a778525672359ae54ea160f7a868badd8a0 (diff) | |
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.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/cpu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 716c98b35ac7..c62ae016675d 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -596,6 +596,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) err = -EBUSY; goto restore_cpus; } + migrate_enable(); cpu_hotplug_begin(); err = cpu_unplug_begin(cpu); @@ -649,7 +650,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) out_release: cpu_unplug_done(cpu); out_cancel: - migrate_enable(); cpu_hotplug_done(); if (!err) cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); |