diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2014-02-07 20:58:39 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-02-22 18:08:08 +0100 |
| commit | 8f47b1871b8aac98f1a9d93bc3467fb97b65199a (patch) | |
| tree | 0eebff7b82d2cfa93a728a363d0bd4019356d9cf /kernel | |
| parent | db273be2a7d42f92b3471e0f717982928214a650 (diff) | |
sched: Add better debug output for might_sleep()
might_sleep() can tell us where interrupts have been disabled, but we
have no idea what disabled preemption. Add some debug infrastructure.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-4-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a01fe6cfdb9b..c94e851dc981 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2501,8 +2501,13 @@ void __kprobes preempt_count_add(int val) DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= PREEMPT_MASK - 10); #endif - if (preempt_count() == val) - trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); + if (preempt_count() == val) { + unsigned long ip = get_parent_ip(CALLER_ADDR1); +#ifdef CONFIG_DEBUG_PREEMPT + current->preempt_disable_ip = ip; +#endif + trace_preempt_off(CALLER_ADDR0, ip); + } } EXPORT_SYMBOL(preempt_count_add); @@ -2545,6 +2550,13 @@ static noinline void __schedule_bug(struct task_struct *prev) print_modules(); if (irqs_disabled()) print_irqtrace_events(prev); +#ifdef CONFIG_DEBUG_PREEMPT + if (in_atomic_preempt_off()) { + pr_err("Preemption disabled at:"); + print_ip_sym(current->preempt_disable_ip); + pr_cont("\n"); + } +#endif dump_stack(); add_taint(TAINT_WARN, LOCKDEP_STILL_OK); } @@ -6946,6 +6958,13 @@ void __might_sleep(const char *file, int line, int preempt_offset) debug_show_held_locks(current); if (irqs_disabled()) print_irqtrace_events(current); +#ifdef CONFIG_DEBUG_PREEMPT + if (!preempt_count_equals(preempt_offset)) { + pr_err("Preemption disabled at:"); + print_ip_sym(current->preempt_disable_ip); + pr_cont("\n"); + } +#endif dump_stack(); } EXPORT_SYMBOL(__might_sleep); |