diff options
| author | Tiejun Chen <tiejun.chen@windriver.com> | 2013-11-07 10:06:07 +0800 |
|---|---|---|
| committer | Steven Rostedt <rostedt@rostedt.homelinux.com> | 2013-12-16 21:03:54 -0500 |
| commit | 0c24509cda5de3fc766dad127caaa192248dfb2a (patch) | |
| tree | a24ae41d972857092d499d6cc0b05e86fa5676dd | |
| parent | 10e4b1ff05e7028c76431751b92a7d5e4d6107b6 (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 98f2ea369cce..da6e12848ded 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -594,6 +594,7 @@ 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); @@ -647,7 +648,6 @@ 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); |