[tip:core/locking] lockdep: add stack dumps to asserts

From: Peter Zijlstra
Date: Tue Mar 31 2009 - 08:58:40 EST


Commit-ID: eedeeabdeeadb016b8c783e3620d06b98d0cb4e1
Gitweb: http://git.kernel.org/tip/eedeeabdeeadb016b8c783e3620d06b98d0cb4e1
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Wed, 18 Mar 2009 12:38:47 +0100
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 31 Mar 2009 14:53:01 +0200

lockdep: add stack dumps to asserts

Have a better idea about exactly which loc causes a lockdep
limit overflow. Often it's a bug or inefficiency in that
subsystem.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <1237376327.5069.253.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>


---
kernel/lockdep.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 981cd48..a288ae1 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -792,6 +792,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)

printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
printk("turning off the locking correctness validator.\n");
+ dump_stack();
return NULL;
}
class = lock_classes + nr_lock_classes++;
@@ -855,6 +856,7 @@ static struct lock_list *alloc_list_entry(void)

printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n");
printk("turning off the locking correctness validator.\n");
+ dump_stack();
return NULL;
}
return list_entries + nr_list_entries++;
@@ -1681,6 +1683,7 @@ cache_hit:

printk("BUG: MAX_LOCKDEP_CHAINS too low!\n");
printk("turning off the locking correctness validator.\n");
+ dump_stack();
return 0;
}
chain = lock_chains + nr_lock_chains++;
@@ -2540,6 +2543,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
debug_locks_off();
printk("BUG: MAX_LOCKDEP_SUBCLASSES too low!\n");
printk("turning off the locking correctness validator.\n");
+ dump_stack();
return 0;
}

@@ -2636,6 +2640,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
debug_locks_off();
printk("BUG: MAX_LOCK_DEPTH too low!\n");
printk("turning off the locking correctness validator.\n");
+ dump_stack();
return 0;
}

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