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authorIngo Molnar <mingo@elte.hu>2006-12-13 00:34:43 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-13 09:05:50 -0800
commit3117df0453828bd045c16244e6f50e5714667a8a (patch)
tree4f24e5b4024359dd42c91b84cbc25280f21b7314
parent27c3b23226fc649de47e4886ccbf994482f388ba (diff)
downloadop-kernel-dev-3117df0453828bd045c16244e6f50e5714667a8a.zip
op-kernel-dev-3117df0453828bd045c16244e6f50e5714667a8a.tar.gz
[PATCH] lockdep: print irq-trace info on asserts
When we print an assert due to scheduling-in-atomic bugs, and if lockdep is enabled, then the IRQ tracing information of lockdep can be printed to pinpoint the code location that disabled interrupts. This saved me quite a bit of debugging time in cases where the backtrace did not identify the irq-disabling site well enough. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/linux/lockdep.h16
-rw-r--r--kernel/lockdep.c6
-rw-r--r--kernel/sched.c4
3 files changed, 18 insertions, 8 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 498bfbd..ea097dd 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -281,15 +281,25 @@ struct lock_class_key { };
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
extern void early_init_irq_lock_class(void);
#else
-# define early_init_irq_lock_class() do { } while (0)
+static inline void early_init_irq_lock_class(void)
+{
+}
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
extern void early_boot_irqs_off(void);
extern void early_boot_irqs_on(void);
+extern void print_irqtrace_events(struct task_struct *curr);
#else
-# define early_boot_irqs_off() do { } while (0)
-# define early_boot_irqs_on() do { } while (0)
+static inline void early_boot_irqs_off(void)
+{
+}
+static inline void early_boot_irqs_on(void)
+{
+}
+static inline void print_irqtrace_events(struct task_struct *curr)
+{
+}
#endif
/*
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 69e92c6..07a3d74 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1447,7 +1447,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this,
return print_irq_inversion_bug(curr, backwards_match, this, 0, irqclass);
}
-static inline void print_irqtrace_events(struct task_struct *curr)
+void print_irqtrace_events(struct task_struct *curr)
{
printk("irq event stamp: %u\n", curr->irq_events);
printk("hardirqs last enabled at (%u): ", curr->hardirq_enable_event);
@@ -1460,10 +1460,6 @@ static inline void print_irqtrace_events(struct task_struct *curr)
print_ip_sym(curr->softirq_disable_ip);
}
-#else
-static inline void print_irqtrace_events(struct task_struct *curr)
-{
-}
#endif
static int
diff --git a/kernel/sched.c b/kernel/sched.c
index 8a0afb9..5cd833b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3429,6 +3429,8 @@ asmlinkage void __sched schedule(void)
"%s/0x%08x/%d\n",
current->comm, preempt_count(), current->pid);
debug_show_held_locks(current);
+ if (irqs_disabled())
+ print_irqtrace_events(current);
dump_stack();
}
profile_hit(SCHED_PROFILING, __builtin_return_address(0));
@@ -6977,6 +6979,8 @@ void __might_sleep(char *file, int line)
printk("in_atomic():%d, irqs_disabled():%d\n",
in_atomic(), irqs_disabled());
debug_show_held_locks(current);
+ if (irqs_disabled())
+ print_irqtrace_events(current);
dump_stack();
}
#endif
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