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| author | Tiejun Chen <tiejun.chen@windriver.com> | 2013-11-07 10:06:07 +0800 |
|---|---|---|
| committer | Anders Roxell <anders.roxell@linaro.org> | 2015-08-17 08:59:48 +0200 |
| commit | 7596a673439903d18adf43e8dbced4aafdfdf209 (patch) | |
| tree | 21f88c45265857015b7fb7ce958734a43aeef6f7 | |
| parent | 2b4f1753adf061da794a7ffb8ba246a4a8df2de3 (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.
Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
| -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 9b02cb9f605a..c2740a14f77e 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -668,6 +668,7 @@ 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); @@ -744,7 +745,6 @@ 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); |