[PATCH 1/5] sched: Enable might_sleep before initializing drivers.

From: John Stultz
Date: Fri Nov 19 2010 - 21:09:37 EST


From: Arve HjÃnnevÃg <arve@xxxxxxxxxxx>

This allows detection of init bugs in built-in drivers.

CC: Ingo Molnar <mingo@xxxxxxx>
CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Arve HjÃnnevÃg <arve@xxxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
kernel/sched.c | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index aa14a56..0b58415 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -8104,13 +8104,24 @@ static inline int preempt_count_equals(int preempt_offset)
return (nested == PREEMPT_INATOMIC_BASE + preempt_offset);
}

+static int __might_sleep_init_called;
+int __init __might_sleep_init(void)
+{
+ __might_sleep_init_called = 1;
+ return 0;
+}
+early_initcall(__might_sleep_init);
+
void __might_sleep(const char *file, int line, int preempt_offset)
{
#ifdef in_atomic
static unsigned long prev_jiffy; /* ratelimiting */

if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
- system_state != SYSTEM_RUNNING || oops_in_progress)
+ oops_in_progress)
+ return;
+ if (system_state != SYSTEM_RUNNING &&
+ (!__might_sleep_init_called || system_state != SYSTEM_BOOTING))
return;
if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
return;
--
1.7.3.2.146.gca209

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