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| author | Thomas Gleixner <tglx@linutronix.de> | 2017-05-16 20:42:48 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-05-23 10:01:38 +0200 |
| commit | 1c3c5eab171590f86edd8d31389d61dd1efe3037 (patch) | |
| tree | 9c44caada92823283f4de3fce475045e22d4ca2a /init/main.c | |
| parent | 69a78ff226fe0241ab6cb9dd961667be477e3cf7 (diff) | |
| download | lwn-1c3c5eab171590f86edd8d31389d61dd1efe3037.tar.gz lwn-1c3c5eab171590f86edd8d31389d61dd1efe3037.zip | |
sched/core: Enable might_sleep() and smp_processor_id() checks early
might_sleep() and smp_processor_id() checks are enabled after the boot
process is done. That hides bugs in the SMP bringup and driver
initialization code.
Enable it right when the scheduler starts working, i.e. when init task and
kthreadd have been created and right before the idle task enables
preemption.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.272225698@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'init/main.c')
| -rw-r--r-- | init/main.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/init/main.c b/init/main.c index badae3bf08f1..df58a416dd1d 100644 --- a/init/main.c +++ b/init/main.c @@ -414,6 +414,16 @@ static noinline void __ref rest_init(void) rcu_read_lock(); kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); rcu_read_unlock(); + + /* + * Enable might_sleep() and smp_processor_id() checks. + * They cannot be enabled earlier because with CONFIG_PRREMPT=y + * kernel_thread() would trigger might_sleep() splats. With + * CONFIG_PREEMPT_VOLUNTARY=y the init task might have scheduled + * already, but it's stuck on the kthreadd_done completion. + */ + system_state = SYSTEM_SCHEDULING; + complete(&kthreadd_done); /* |