diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2012-10-05 08:56:15 +0100 |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2013-08-13 16:08:58 -0400 |
commit | 8c874b19cbc3f4706bd2e5e9fd587d84dc3f38ea (patch) | |
tree | 21c4e78b5d5f6dff79767fd15e571be4e31ec152 | |
parent | d31dd1ef9a928bbaf9b32255bba079edb85c4f30 (diff) |
sched: 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>
-rw-r--r-- | include/linux/sched.h | 3 | ||||
-rw-r--r-- | kernel/sched/core.c | 23 |
2 files changed, 24 insertions, 2 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 0e1b4b9e64e7..aab87b7bbf7b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1643,6 +1643,9 @@ struct task_struct { pte_t kmap_pte[KM_TYPE_NR]; # endif #endif +#ifdef CONFIG_DEBUG_PREEMPT + unsigned long preempt_disable_ip; +#endif }; #ifdef CONFIG_NUMA_BALANCING diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 90af179d1d49..a2ef28f70209 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2791,8 +2791,13 @@ void __kprobes add_preempt_count(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(add_preempt_count); @@ -2835,6 +2840,13 @@ 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); } @@ -7312,6 +7324,13 @@ 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); |