The patch titled
lockdep debugging: give stacktrace for init_error
has been added to the -mm tree. Its filename is
lockdep-debugging-give-stacktrace-for-init_error.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: lockdep debugging: give stacktrace for init_error
From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/lockdep.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff -puN kernel/lockdep.c~lockdep-debugging-give-stacktrace-for-init_error kernel/lockdep.c
--- a/kernel/lockdep.c~lockdep-debugging-give-stacktrace-for-init_error
+++ a/kernel/lockdep.c
@@ -291,6 +291,11 @@ 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:
@@ -1170,6 +1175,7 @@ look_up_lock_class(struct lockdep_map *l
if (unlikely(!lockdep_initialized)) {
lockdep_init();
lockdep_init_error = 1;
+ save_stack_trace(&lockdep_init_trace);
}
#endif
@@ -2636,8 +2642,11 @@ 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
}
_
Patches currently in -mm which might be from johannes@xxxxxxxxxxxxxxxx are
git-powerpc.patch
git-netdev-all.patch
git-net.patch
git-ocfs2.patch
tidy-up-usermode-helper-waiting-a-bit-fix.patch
lockdep-debugging-give-stacktrace-for-init_error.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
