diff options
| author | Johannes Berg <johannes@sipsolutions.net> | 2007-07-19 01:49:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-19 10:04:49 -0700 |
| commit | c71063c9c9dc232d0d51f936f237f7dc5681e8e3 (patch) | |
| tree | 3f56b9e12c86b2afe9e613e868001654240aabb7 /kernel/lockdep.c | |
| parent | d38e1d5aaee384698fcef9455d6e2df1d062a1d0 (diff) | |
| download | lwn-c71063c9c9dc232d0d51f936f237f7dc5681e8e3.tar.gz lwn-c71063c9c9dc232d0d51f936f237f7dc5681e8e3.zip | |
lockdep debugging: give stacktrace for init_error
When I started adding support for lockdep to 64-bit powerpc, I got a
lockdep_init_error and with this patch was able to pinpoint why and where
to put lockdep_init(). Let's support this generally for others adding
lockdep support to their architecture.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/lockdep.c')
| -rw-r--r-- | kernel/lockdep.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 156fce4960c3..734da579ad13 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -375,6 +375,11 @@ unsigned int max_recursion_depth; * about it later on, in lockdep_info(). */ static int lockdep_init_error; +static unsigned long lockdep_init_trace_data[20]; +static struct stack_trace lockdep_init_trace = { + .max_entries = ARRAY_SIZE(lockdep_init_trace_data), + .entries = lockdep_init_trace_data, +}; /* * Various lockdep statistics: @@ -662,6 +667,7 @@ look_up_lock_class(struct lockdep_map *lock, unsigned int subclass) if (unlikely(!lockdep_initialized)) { lockdep_init(); lockdep_init_error = 1; + save_stack_trace(&lockdep_init_trace); } #endif @@ -3040,8 +3046,11 @@ void __init lockdep_info(void) sizeof(struct held_lock) * MAX_LOCK_DEPTH); #ifdef CONFIG_DEBUG_LOCKDEP - if (lockdep_init_error) - printk("WARNING: lockdep init error! Arch code didnt call lockdep_init() early enough?\n"); + if (lockdep_init_error) { + printk("WARNING: lockdep init error! Arch code didn't call lockdep_init() early enough?\n"); + printk("Call stack leading to lockdep invocation was:\n"); + print_stack_trace(&lockdep_init_trace, 0); + } #endif } |